From 36d22d82aa202bb199967e9512281e9a53db42c9 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 21:33:14 +0200
Subject: Adding upstream version 115.7.0esr.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 .../dedicated-worker-import-blob-url.any.js        |  26 ++
 .../modules/dedicated-worker-import-csp.html       | 120 ++++++++
 ...icated-worker-import-data-url-cross-origin.html |  43 +++
 .../dedicated-worker-import-data-url.any.js        |  22 ++
 .../modules/dedicated-worker-import-failure.html   |  54 ++++
 .../modules/dedicated-worker-import-meta.html      |  59 ++++
 .../modules/dedicated-worker-import-referrer.html  | 244 ++++++++++++++++
 .../workers/modules/dedicated-worker-import.any.js |  22 ++
 .../dedicated-worker-options-credentials.html      | 304 ++++++++++++++++++++
 ...dicated-worker-options-credentials.html.headers |   2 +
 .../modules/dedicated-worker-options-type.html     |  46 +++
 .../dedicated-worker-parse-error-failure.html      |  51 ++++
 ...dynamic-import-and-then-static-import-worker.js |  32 +++
 .../dynamic-import-data-url-block-cross-origin.js  |  24 ++
 .../resources/dynamic-import-given-url-worker.js   |  21 ++
 ...remote-origin-credentials-checker-worker.sub.js |  15 +
 ...rt-remote-origin-referrer-checker-worker.sub.js |  16 ++
 ...namic-import-remote-origin-script-worker.sub.js |  17 ++
 ...mport-same-origin-credentials-checker-worker.js |  13 +
 ...c-import-same-origin-referrer-checker-worker.js |  15 +
 .../dynamic-import-script-block-cross-origin.js    |  24 ++
 .../modules/resources/dynamic-import-worker.js     |  32 +++
 .../workers/modules/resources/empty-worker.js      |   1 +
 .../resources/eval-dynamic-import-worker.js        |  29 ++
 .../modules/resources/export-block-cross-origin.js |   1 +
 .../modules/resources/export-credentials.py        |  15 +
 .../resources/export-on-dynamic-import-script.js   |   8 +
 .../export-on-dynamic-import-script.js.headers     |   1 +
 .../modules/resources/export-on-load-script.js     |   1 +
 .../resources/export-on-load-script.js.headers     |   1 +
 .../modules/resources/export-on-load-script.py     |  15 +
 .../resources/export-on-static-import-script.js    |   3 +
 .../export-on-static-import-script.js.headers      |   1 +
 .../modules/resources/export-referrer-checker.py   |   9 +
 .../modules/resources/import-meta-url-export.js    |   1 +
 .../modules/resources/import-meta-url-worker.js    |  10 +
 .../modules/resources/import-scripts-worker.js     |  33 +++
 .../workers/modules/resources/import-test-cases.js |  59 ++++
 .../resources/nested-dynamic-import-worker.js      |  34 +++
 .../resources/nested-static-import-worker.js       |  21 ++
 .../resources/new-shared-worker-window.html        |  19 ++
 .../modules/resources/new-worker-window.html       |  19 ++
 .../resources/post-message-on-load-worker.js       |  10 +
 .../modules/resources/postmessage-credentials.py   |  22 ++
 .../resources/postmessage-referrer-checker.py      |  16 ++
 .../tests/workers/modules/resources/redirect.py    |   8 +
 ...static-import-and-then-dynamic-import-worker.js |  34 +++
 .../static-import-data-url-block-cross-origin.js   |  14 +
 .../static-import-non-existent-script-worker.js    |   1 +
 .../resources/static-import-redirect-worker.js     |  21 ++
 ...remote-origin-credentials-checker-worker.sub.js |  12 +
 ...rt-remote-origin-referrer-checker-worker.sub.js |  12 +
 ...tatic-import-remote-origin-script-worker.sub.js |  20 ++
 ...mport-same-origin-credentials-checker-worker.js |  11 +
 ...c-import-same-origin-referrer-checker-worker.js |  11 +
 .../static-import-script-block-cross-origin.js     |  14 +
 .../resources/static-import-syntax-error.js        |   1 +
 .../modules/resources/static-import-worker.js      |  21 ++
 .../workers/modules/resources/syntax-error.js      |   1 +
 .../tests/workers/modules/resources/throw.js       |   1 +
 .../shared-worker-import-blob-url.window.js        |  26 ++
 .../workers/modules/shared-worker-import-csp.html  | 128 +++++++++
 ...shared-worker-import-data-url-cross-origin.html |  43 +++
 .../shared-worker-import-data-url.window.js        |  23 ++
 .../modules/shared-worker-import-failure.html      |  67 +++++
 .../workers/modules/shared-worker-import-meta.html |  49 ++++
 .../modules/shared-worker-import-referrer.html     | 259 +++++++++++++++++
 .../workers/modules/shared-worker-import.window.js |  22 ++
 .../modules/shared-worker-options-credentials.html | 309 +++++++++++++++++++++
 .../shared-worker-options-credentials.html.headers |   2 +
 .../modules/shared-worker-options-type.html        |  48 ++++
 .../modules/shared-worker-parse-error-failure.html |  49 ++++
 72 files changed, 2738 insertions(+)
 create mode 100644 testing/web-platform/tests/workers/modules/dedicated-worker-import-blob-url.any.js
 create mode 100644 testing/web-platform/tests/workers/modules/dedicated-worker-import-csp.html
 create mode 100644 testing/web-platform/tests/workers/modules/dedicated-worker-import-data-url-cross-origin.html
 create mode 100644 testing/web-platform/tests/workers/modules/dedicated-worker-import-data-url.any.js
 create mode 100644 testing/web-platform/tests/workers/modules/dedicated-worker-import-failure.html
 create mode 100644 testing/web-platform/tests/workers/modules/dedicated-worker-import-meta.html
 create mode 100644 testing/web-platform/tests/workers/modules/dedicated-worker-import-referrer.html
 create mode 100644 testing/web-platform/tests/workers/modules/dedicated-worker-import.any.js
 create mode 100644 testing/web-platform/tests/workers/modules/dedicated-worker-options-credentials.html
 create mode 100644 testing/web-platform/tests/workers/modules/dedicated-worker-options-credentials.html.headers
 create mode 100644 testing/web-platform/tests/workers/modules/dedicated-worker-options-type.html
 create mode 100644 testing/web-platform/tests/workers/modules/dedicated-worker-parse-error-failure.html
 create mode 100644 testing/web-platform/tests/workers/modules/resources/dynamic-import-and-then-static-import-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/dynamic-import-data-url-block-cross-origin.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/dynamic-import-given-url-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/dynamic-import-remote-origin-credentials-checker-worker.sub.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/dynamic-import-remote-origin-referrer-checker-worker.sub.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/dynamic-import-remote-origin-script-worker.sub.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/dynamic-import-same-origin-credentials-checker-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/dynamic-import-same-origin-referrer-checker-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/dynamic-import-script-block-cross-origin.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/dynamic-import-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/empty-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/eval-dynamic-import-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/export-block-cross-origin.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/export-credentials.py
 create mode 100644 testing/web-platform/tests/workers/modules/resources/export-on-dynamic-import-script.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/export-on-dynamic-import-script.js.headers
 create mode 100644 testing/web-platform/tests/workers/modules/resources/export-on-load-script.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/export-on-load-script.js.headers
 create mode 100644 testing/web-platform/tests/workers/modules/resources/export-on-load-script.py
 create mode 100644 testing/web-platform/tests/workers/modules/resources/export-on-static-import-script.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/export-on-static-import-script.js.headers
 create mode 100644 testing/web-platform/tests/workers/modules/resources/export-referrer-checker.py
 create mode 100644 testing/web-platform/tests/workers/modules/resources/import-meta-url-export.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/import-meta-url-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/import-scripts-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/import-test-cases.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/nested-dynamic-import-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/nested-static-import-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/new-shared-worker-window.html
 create mode 100644 testing/web-platform/tests/workers/modules/resources/new-worker-window.html
 create mode 100644 testing/web-platform/tests/workers/modules/resources/post-message-on-load-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/postmessage-credentials.py
 create mode 100644 testing/web-platform/tests/workers/modules/resources/postmessage-referrer-checker.py
 create mode 100644 testing/web-platform/tests/workers/modules/resources/redirect.py
 create mode 100644 testing/web-platform/tests/workers/modules/resources/static-import-and-then-dynamic-import-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/static-import-data-url-block-cross-origin.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/static-import-non-existent-script-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/static-import-redirect-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/static-import-remote-origin-credentials-checker-worker.sub.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/static-import-remote-origin-referrer-checker-worker.sub.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/static-import-remote-origin-script-worker.sub.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/static-import-same-origin-credentials-checker-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/static-import-same-origin-referrer-checker-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/static-import-script-block-cross-origin.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/static-import-syntax-error.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/static-import-worker.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/syntax-error.js
 create mode 100644 testing/web-platform/tests/workers/modules/resources/throw.js
 create mode 100644 testing/web-platform/tests/workers/modules/shared-worker-import-blob-url.window.js
 create mode 100644 testing/web-platform/tests/workers/modules/shared-worker-import-csp.html
 create mode 100644 testing/web-platform/tests/workers/modules/shared-worker-import-data-url-cross-origin.html
 create mode 100644 testing/web-platform/tests/workers/modules/shared-worker-import-data-url.window.js
 create mode 100644 testing/web-platform/tests/workers/modules/shared-worker-import-failure.html
 create mode 100644 testing/web-platform/tests/workers/modules/shared-worker-import-meta.html
 create mode 100644 testing/web-platform/tests/workers/modules/shared-worker-import-referrer.html
 create mode 100644 testing/web-platform/tests/workers/modules/shared-worker-import.window.js
 create mode 100644 testing/web-platform/tests/workers/modules/shared-worker-options-credentials.html
 create mode 100644 testing/web-platform/tests/workers/modules/shared-worker-options-credentials.html.headers
 create mode 100644 testing/web-platform/tests/workers/modules/shared-worker-options-type.html
 create mode 100644 testing/web-platform/tests/workers/modules/shared-worker-parse-error-failure.html

(limited to 'testing/web-platform/tests/workers/modules')

diff --git a/testing/web-platform/tests/workers/modules/dedicated-worker-import-blob-url.any.js b/testing/web-platform/tests/workers/modules/dedicated-worker-import-blob-url.any.js
new file mode 100644
index 0000000000..e5d79add73
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/dedicated-worker-import-blob-url.any.js
@@ -0,0 +1,26 @@
+// META: script=/workers/modules/resources/import-test-cases.js
+
+// Imports |testCase.scriptURL| on a dedicated worker loaded from a blob URL,
+// and waits until the list of imported modules is sent from the worker. Passes
+// if the list is equal to |testCase.expectation|.
+function import_blob_url_test(testCase) {
+  promise_test(async () => {
+    const importURL = new URL(testCase.scriptURL, location.href);
+    const blob = new Blob([`import "${importURL}";`],
+                          { type: 'text/javascript' });
+    const blobURL = URL.createObjectURL(blob);
+    const worker = new Worker(blobURL, { type: 'module'});
+    worker.postMessage('Send message for tests from main script.');
+    const msgEvent = await new Promise((resolve, reject) => {
+      worker.onmessage = resolve;
+      worker.onerror = error => {
+        const msg = error instanceof ErrorEvent ? error.message
+                                                : 'unknown error';
+        reject(msg);
+      };
+    });
+    assert_array_equals(msgEvent.data, testCase.expectation);
+  }, testCase.description);
+}
+
+testCases.forEach(import_blob_url_test);
diff --git a/testing/web-platform/tests/workers/modules/dedicated-worker-import-csp.html b/testing/web-platform/tests/workers/modules/dedicated-worker-import-csp.html
new file mode 100644
index 0000000000..20b03a7276
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/dedicated-worker-import-csp.html
@@ -0,0 +1,120 @@
+<!DOCTYPE html>
+<title>DedicatedWorker: CSP for ES Modules</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+
+async function openWindow(url) {
+  const win = window.open(url, '_blank');
+  add_result_callback(() => win.close());
+  const msg_event = await new Promise(resolve => window.onmessage = resolve);
+  assert_equals(msg_event.data, 'LOADED');
+  return win;
+}
+
+function import_csp_test(
+    cspHeader, importType, expectedImportedModules, description) {
+  // Append CSP header to windowURL for static import tests since static import
+  // scripts should obey Window's CSP.
+  const windowURL = `resources/new-worker-window.html` +
+      `${importType === 'static'
+          ? '?pipe=header(Content-Security-Policy, ' + cspHeader + ')'
+          : ''}`;
+  // Append CSP header to scriptURL for dynamic import tests since dynamic
+  // import scripts should obey Worker script's response's CSP.
+  const scriptURL = `${importType}-import-remote-origin-script-worker.sub.js` +
+      `${importType === 'dynamic'
+          ? '?pipe=header(Content-Security-Policy, ' + cspHeader + ')'
+          : ''}`;
+  promise_test(async () => {
+    const win = await openWindow(windowURL);
+    // Ask the window to start a dedicated worker.
+    win.postMessage(scriptURL, '*');
+    const msg_event = await new Promise(resolve => window.onmessage = resolve);
+    assert_array_equals(msg_event.data, expectedImportedModules);
+  }, description);
+}
+
+// Tests for static import.
+//
+// Static import should obey the worker-src directive and the script-src
+// directive. If the both directives are specified, the worker-src directive
+// should be prioritized.
+//
+// Step 1: "If the result of executing 6.6.1.11 Get the effective directive for
+// request on request is "worker-src", and policy contains a directive whose
+// name is "worker-src", return "Allowed"."
+// "Note: If worker-src is present, we’ll defer to it when handling worker
+// requests."
+// https://w3c.github.io/webappsec-csp/#script-src-pre-request
+
+import_csp_test(
+    "worker-src 'self' 'unsafe-inline'",
+    "static",
+    ['ERROR'],
+    "worker-src 'self' directive should disallow cross origin static import.");
+
+import_csp_test(
+    "worker-src * 'unsafe-inline'",
+    "static",
+    ["export-on-load-script.js"],
+    "worker-src * directive should allow cross origin static import.")
+
+import_csp_test(
+    "script-src 'self' 'unsafe-inline'",
+    "static",
+    ['ERROR'],
+    "script-src 'self' directive should disallow cross origin static import.");
+
+import_csp_test(
+    "script-src * 'unsafe-inline'",
+    "static",
+    ["export-on-load-script.js"],
+    "script-src * directive should allow cross origin static import.")
+
+import_csp_test(
+    "worker-src *; script-src 'self' 'unsafe-inline'",
+    "static",
+    ["export-on-load-script.js"],
+    "worker-src * directive should override script-src 'self' directive and " +
+        "allow cross origin static import.");
+
+import_csp_test(
+    "worker-src 'self'; script-src * 'unsafe-inline'",
+    "static",
+    ['ERROR'],
+    "worker-src 'self' directive should override script-src * directive and " +
+        "disallow cross origin static import.");
+
+// Tests for dynamic import.
+//
+// Dynamic import should obey the script-src directive instead of the worker-src
+// directive according to the specs:
+//
+// Dynamic import has the "script" destination.
+// Step 2.4: "Fetch a module script graph given url, ..., "script", ..."
+// https://html.spec.whatwg.org/multipage/webappapis.html#hostimportmoduledynamically(referencingscriptormodule,-specifier,-promisecapability)
+//
+// The "script" destination should obey the script-src CSP directive.
+// Step 2: "If request's destination is script-like:"
+// https://w3c.github.io/webappsec-csp/#script-src-pre-request
+
+import_csp_test(
+    "script-src 'self' 'unsafe-inline'",
+    "dynamic",
+    ['ERROR'],
+    "script-src 'self' directive should disallow cross origin dynamic import.");
+
+import_csp_test(
+    "script-src * 'unsafe-inline'",
+    "dynamic",
+    ["export-on-load-script.js"],
+    "script-src * directive should allow cross origin dynamic import.")
+
+import_csp_test(
+    "worker-src 'self' 'unsafe-inline'",
+    "dynamic",
+    ["export-on-load-script.js"],
+    "worker-src 'self' directive should not take effect on dynamic import.");
+
+</script>
diff --git a/testing/web-platform/tests/workers/modules/dedicated-worker-import-data-url-cross-origin.html b/testing/web-platform/tests/workers/modules/dedicated-worker-import-data-url-cross-origin.html
new file mode 100644
index 0000000000..37390947b6
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/dedicated-worker-import-data-url-cross-origin.html
@@ -0,0 +1,43 @@
+<!DOCTYPE html>
+<title>DedicatedWorker: ES modules for data URL workers</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+
+const import_from_data_url_worker_test = (importType, isDataURL, expectation) => {
+  promise_test(async () => {
+    const importURL = new URL(`resources/${importType}-import-` +
+        `${isDataURL ? 'data-url' : 'script'}-block-cross-origin.js`,
+        location.href) + '?pipe=header(Access-Control-Allow-Origin, *)';
+    const dataURL = `data:text/javascript,import "${importURL}";`;
+    const worker = new Worker(dataURL, { type: 'module' });
+    worker.postMessage('Send message for tests from main script.');
+    const msgEvent =
+        await new Promise(resolve => worker.onmessage = resolve);
+    assert_array_equals(msgEvent.data,
+        expectation === 'blocked' ? ['ERROR']
+                                  : ['export-block-cross-origin.js']);
+  }, `${importType} import ${isDataURL ? 'data url' : 'script'} from data: ` +
+     `URL should be ${expectation}.`);
+}
+
+// Static import should obey the outside settings.
+// SecurityOrigin of the outside settings is decided by Window.
+import_from_data_url_worker_test('static', true, 'allowed');
+import_from_data_url_worker_test('static', false, 'allowed');
+
+
+// Dynamic import should obey the inside settings.
+// SecurityOrigin of the inside settings is a unique opaque origin.
+//
+// Data url script is cross-origin to the inside settings' SecurityOrigin, but
+// dynamic importing it is allowed.
+// https://fetch.spec.whatwg.org/#concept-main-fetch
+// Step 5: request’s current URL’s scheme is "data" [spec text]
+import_from_data_url_worker_test('dynamic', true, 'allowed');
+
+// Non-data url script is cross-origin to the inside settings' SecurityOrigin.
+// It should be blocked.
+import_from_data_url_worker_test('dynamic', false, 'blocked');
+
+</script>
diff --git a/testing/web-platform/tests/workers/modules/dedicated-worker-import-data-url.any.js b/testing/web-platform/tests/workers/modules/dedicated-worker-import-data-url.any.js
new file mode 100644
index 0000000000..0d8510da0c
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/dedicated-worker-import-data-url.any.js
@@ -0,0 +1,22 @@
+// META: script=/workers/modules/resources/import-test-cases.js
+
+// Imports |testCase.scriptURL| on a dedicated worker loaded from a data URL,
+// and waits until the list of imported modules is sent from the worker. Passes
+// if the list is equal to |testCase.expectation|.
+function import_data_url_test(testCase) {
+  promise_test(async () => {
+    // The Access-Control-Allow-Origin header is necessary because a worker
+    // loaded from a data URL has a null origin and import() on the worker
+    // without the header is blocked.
+    const importURL = new URL(testCase.scriptURL, location.href) +
+        '?pipe=header(Access-Control-Allow-Origin, *)';
+    const dataURL = `data:text/javascript,import "${importURL}";`;
+
+    const worker = new Worker(dataURL, { type: 'module'});
+    worker.postMessage('Send message for tests from main script.');
+    const msgEvent = await new Promise(resolve => worker.onmessage = resolve);
+    assert_array_equals(msgEvent.data, testCase.expectation);
+  }, testCase.description);
+}
+
+testCases.forEach(import_data_url_test);
diff --git a/testing/web-platform/tests/workers/modules/dedicated-worker-import-failure.html b/testing/web-platform/tests/workers/modules/dedicated-worker-import-failure.html
new file mode 100644
index 0000000000..4c705e7325
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/dedicated-worker-import-failure.html
@@ -0,0 +1,54 @@
+<!DOCTYPE html>
+<title>DedicatedWorker: import failure</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script> setup({allow_uncaught_exception: true}); </script>
+<script>
+
+promise_test(async () => {
+  const scriptURL = 'resources/import-scripts-worker.js';
+  const worker = new Worker(scriptURL, { type: 'module' });
+  const msg_event = await new Promise(resolve => worker.onmessage = resolve);
+  assert_equals(msg_event.data, 'TypeError');
+}, 'importScripts() on module worker should throw an exception.');
+
+promise_test(() => {
+  const scriptURL = 'resources/non-existent-worker.js';
+  const worker = new Worker(scriptURL, { type: 'module' });
+  return new Promise(resolve => worker.onerror = resolve);
+}, 'Worker construction for non-existent script should dispatch an ' +
+   'ErrorEvent.');
+
+promise_test(() => {
+  const scriptURL = 'resources/static-import-non-existent-script-worker.js';
+  const worker = new Worker(scriptURL, { type: 'module' });
+  return new Promise(resolve => worker.onerror = resolve);
+}, 'Static import for non-existent script should dispatch an ErrorEvent.');
+
+promise_test(async () => {
+  const scriptURL = './non-existent-worker.js';
+  const worker = new Worker('resources/dynamic-import-given-url-worker.js',
+                            { type: 'module' });
+  worker.postMessage(scriptURL);
+  const msg_event = await new Promise((resolve, reject) => {
+    worker.onmessage = resolve;
+    worker.onerror = error => {
+      const msg = error instanceof ErrorEvent ? error.message
+                                              : 'unknown error';
+      reject(msg);
+    };
+  });
+  assert_equals(msg_event.data, 'TypeError');
+}, 'Dynamic import for non-existent script should throw an exception.');
+
+test(() => {
+  const scriptURL = 'http://invalid:123$';
+  assert_throws_dom('SyntaxError', () => new Worker(scriptURL, { type: 'module' }));
+}, 'Worker construction for an invalid URL should throw an exception.');
+
+test(() => {
+  const scriptURL = 'file:///static-import-worker.js';
+  assert_throws_dom('SecurityError', () => new Worker(scriptURL, { type: 'module' }));
+}, 'Worker construction for a file URL should throw an exception.');
+
+</script>
diff --git a/testing/web-platform/tests/workers/modules/dedicated-worker-import-meta.html b/testing/web-platform/tests/workers/modules/dedicated-worker-import-meta.html
new file mode 100644
index 0000000000..97a5da870f
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/dedicated-worker-import-meta.html
@@ -0,0 +1,59 @@
+<!DOCTYPE html>
+<title>DedicatedWorker: import.meta</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+
+promise_test(() => {
+  const script_url = 'resources/import-meta-url-worker.js';
+  const worker = new Worker(script_url, { type: 'module' });
+  return new Promise((resolve, reject) => {
+        worker.onmessage = resolve;
+        worker.onerror = error => {
+          const msg = error instanceof ErrorEvent ? error.message
+                                                  : 'unknown error';
+          reject(msg);
+        };
+      })
+      .then(msg_event => assert_true(msg_event.data.endsWith(script_url)));
+}, 'Test import.meta.url on the top-level module script.');
+
+promise_test(() => {
+  const script_url = 'import-meta-url-export.js';
+  const worker = new Worker('resources/dynamic-import-given-url-worker.js',
+                            { type: 'module' });
+  worker.postMessage('./' + script_url);
+  return new Promise((resolve, reject) => {
+        worker.onmessage = resolve;
+        worker.onerror = error => {
+          const msg = error instanceof ErrorEvent ? error.message
+                                                  : 'unknown error';
+          reject(msg);
+        };
+      })
+      .then(msg_event => assert_true(msg_event.data.endsWith(script_url)));
+}, 'Test import.meta.url on the imported module script.');
+
+promise_test(() => {
+  const script_url = 'import-meta-url-export.js';
+  const worker = new Worker('resources/dynamic-import-given-url-worker.js',
+                            { type: 'module' });
+  worker.postMessage('./' + script_url);
+
+  return new Promise((resolve, reject) => {
+        worker.onmessage = resolve;
+        worker.onerror = error => {
+          const msg = error instanceof ErrorEvent ? error.message
+                                                  : 'unknown error';
+          reject(msg);
+        };
+      })
+      .then(msg_event => assert_true(msg_event.data.endsWith(script_url)))
+      .then(() => {
+        worker.postMessage('./' + script_url + '#1');
+        return new Promise(resolve => worker.onmessage = resolve);
+      })
+      .then(msg_event => assert_true(msg_event.data.endsWith(script_url + "#1")));
+}, 'Test import.meta.url on the imported module script with a fragment.');
+
+</script>
diff --git a/testing/web-platform/tests/workers/modules/dedicated-worker-import-referrer.html b/testing/web-platform/tests/workers/modules/dedicated-worker-import-referrer.html
new file mode 100644
index 0000000000..855df62194
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/dedicated-worker-import-referrer.html
@@ -0,0 +1,244 @@
+<!DOCTYPE html>
+<title>DedicatedWorker: Referrer</title>
+<meta name="timeout" content="long">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+
+async function openWindow(url) {
+  const win = window.open(url, '_blank');
+  add_result_callback(() => win.close());
+  const msg_event = await new Promise(resolve => window.onmessage = resolve);
+  assert_equals(msg_event.data, 'LOADED');
+  return win;
+}
+
+// Removes URL parameters from the given URL string and returns it.
+function removeParams(url_string) {
+  if (!url_string)
+    return url_string;
+  let url = new URL(url_string);
+  for (var key of url.searchParams.keys())
+    url.searchParams.delete(key);
+  return url.href;
+}
+
+// Generates a referrer given a fetchType, referrer policy, and a request URL
+// (used to determine whether request is remote-origin or not). This function
+// is used to generate expected referrers.
+function generateExpectedReferrer(referrerURL, referrerPolicy, requestURL) {
+  let generatedReferrer = "";
+  if (referrerPolicy === 'no-referrer')
+    generatedReferrer = "";
+  else if (referrerPolicy === 'origin')
+    generatedReferrer = new URL('resources/' + referrerURL, location.href).origin + '/';
+  else if (referrerPolicy === 'same-origin')
+    generatedReferrer = requestURL.includes('remote') ? "" : new URL('resources/' + referrerURL, location.href).href;
+  else
+    generatedReferrer = new URL('resources/' + referrerURL, location.href).href;
+
+  return generatedReferrer;
+}
+
+// Runs a referrer policy test with the given settings. This opens a new window
+// that starts a dedicated worker.
+//
+// |settings| has options as follows:
+//
+//   settings = {
+//     scriptURL: 'resources/referrer-checker.sub.js',
+//     windowReferrerPolicy: 'no-referrer',
+//     workerReferrerPolicy: 'same-origin',
+//     fetchType: 'top-level' or 'descendant-static' or 'descendant-dynamic'
+//   };
+//
+// - |scriptURL| is used for starting a new worker.
+// - |windowReferrerPolicy| is to set the ReferrerPolicy HTTP header of the
+//   window. This policy should be applied to top-level worker module script
+//   loading and static imports.
+// - |workerReferrerPolicy| is to set the ReferrerPolicy HTTP header of the
+//   worker. This policy should be applied to dynamic imports.
+// - |fetchType| indicates a script whose referrer will be tested.
+function import_referrer_test(settings, description) {
+  promise_test(async () => {
+    let windowURL = 'resources/new-worker-window.html';
+    if (settings.windowReferrerPolicy) {
+      windowURL +=
+          `?pipe=header(Referrer-Policy, ${settings.windowReferrerPolicy})`;
+    }
+
+    let scriptURL = settings.scriptURL;
+    if (settings.workerReferrerPolicy) {
+      // 'sub' is necessary even if the |scriptURL| contains the '.sub'
+      // extension because the extension doesn't work with the 'pipe' parameter.
+      // See an issue on the WPT's repository:
+      // https://github.com/web-platform-tests/wpt/issues/9345
+      scriptURL +=
+          `?pipe=sub|header(Referrer-Policy, ${settings.workerReferrerPolicy})`;
+    }
+
+    const win = await openWindow(windowURL);
+    win.postMessage(scriptURL, '*');
+    const msgEvent = await new Promise(resolve => window.onmessage = resolve);
+
+    // Generate the expected referrer, given:
+    //   - The fetchType of the test
+    //   - Referrer URL to be used
+    //   - Relevant referrer policy
+    //   - Request URL
+    let expectedReferrer;
+    if (settings.fetchType === 'top-level') {
+      // Top-level worker requests have their outgoing referrers set given their
+      // containing window's URL and referrer policy.
+      expectedReferrer = generateExpectedReferrer('new-worker-window.html', settings.windowReferrerPolicy, settings.scriptURL);
+    } else if (settings.fetchType === 'descendant-static') {
+      // Static descendant script requests from a worker have their outgoing
+      // referrer set given their containing script's URL and containing
+      // window's referrer policy.
+
+      // In the below cases, the referrer URL and the request URLs are the same
+      // because the initial request (for the top-level worker script) should
+      // act as the referrer for future descendant requests.
+      expectedReferrer = generateExpectedReferrer(settings.scriptURL, settings.windowReferrerPolicy, settings.scriptURL);
+    } else if (settings.fetchType === 'descendant-dynamic') {
+      // Dynamic descendant script requests from a worker have their outgoing
+      // referrer set given their containing script's URL and referrer policy.
+      expectedReferrer = generateExpectedReferrer(settings.scriptURL, settings.workerReferrerPolicy, settings.scriptURL);
+    }
+
+    // Delete query parameters from the actual referrer to make it easy to match
+    // it with the expected referrer.
+    const actualReferrer = removeParams(msgEvent.data);
+
+    assert_equals(actualReferrer, expectedReferrer);
+  }, description);
+}
+
+// Tests for top-level worker module script loading.
+//
+// Top-level worker module scripts should inherit the containing window's
+// referrer policy when using the containing window's URL as the referrer.
+//
+// [Current document]
+// --(open)--> [Window] whose referrer policy is |windowReferrerPolicy|.
+//   --(new Worker)--> [Worker] should respect [windowReferrerPolicy| when
+//                     using [Window]'s URL as the referrer.
+
+import_referrer_test(
+    { scriptURL: 'postmessage-referrer-checker.py',
+      windowReferrerPolicy: 'no-referrer',
+      fetchType: 'top-level' },
+    'Same-origin top-level module script loading with "no-referrer" referrer ' +
+        'policy');
+
+import_referrer_test(
+    { scriptURL: 'postmessage-referrer-checker.py',
+      windowReferrerPolicy: 'origin',
+      fetchType: 'top-level' },
+    'Same-origin top-level module script loading with "origin" referrer ' +
+        'policy');
+
+import_referrer_test(
+    { scriptURL: 'postmessage-referrer-checker.py',
+      windowReferrerPolicy: 'same-origin',
+      fetchType: 'top-level' },
+    'Same-origin top-level module script loading with "same-origin" referrer ' +
+        'policy');
+
+// Tests for static imports.
+//
+// Static imports should inherit the containing window's referrer policy when
+// using the containing module script's URL as the referrer.
+// Note: This is subject to change in the future; see
+// https://github.com/w3c/webappsec-referrer-policy/issues/111.
+//
+// [Current document]
+// --(open)--> [Window] whose referrer policy is |windowReferrerPolicy|.
+//   --(new Worker)--> [Worker]
+//     --(static import)--> [Script] should respect |windowReferrerPolicy| when
+//                          using [Worker]'s URL as the referrer.
+
+import_referrer_test(
+    { scriptURL: 'static-import-same-origin-referrer-checker-worker.js',
+      windowReferrerPolicy: 'no-referrer',
+      fetchType: 'descendant-static' },
+    'Same-origin static import with "no-referrer" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'static-import-same-origin-referrer-checker-worker.js',
+      windowReferrerPolicy: 'origin',
+      fetchType: 'descendant-static' },
+    'Same-origin static import with "origin" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'static-import-same-origin-referrer-checker-worker.js',
+      windowReferrerPolicy: 'same-origin',
+      fetchType: 'descendant-static' },
+    'Same-origin static import with "same-origin" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'static-import-remote-origin-referrer-checker-worker.sub.js',
+      windowReferrerPolicy: 'no-referrer',
+      fetchType: 'descendant-static' },
+    'Cross-origin static import with "no-referrer" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'static-import-remote-origin-referrer-checker-worker.sub.js',
+      windowReferrerPolicy: 'origin',
+      fetchType: 'descendant-static' },
+    'Cross-origin static import with "origin" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'static-import-remote-origin-referrer-checker-worker.sub.js',
+      windowReferrerPolicy: 'same-origin',
+      fetchType: 'descendant-static' },
+    'Cross-origin static import with "same-origin" referrer policy.');
+
+// Tests for dynamic imports.
+//
+// Dynamic imports should inherit the containing script's referrer policy if
+// set, and use the default referrer policy otherwise, when using the
+// containing script's URL as the referrer.
+//
+// [Current document]
+// --(open)--> [Window]
+//   --(new Worker)--> [Worker] whose referrer policy is |workerReferrerPolicy|.
+//     --(dynamic import)--> [Script] should respect |workerReferrerPolicy| when
+//                           using [Worker]'s URL as the referrer.
+
+import_referrer_test(
+    { scriptURL: 'dynamic-import-same-origin-referrer-checker-worker.js',
+      workerReferrerPolicy: 'no-referrer',
+      fetchType: 'descendant-dynamic' },
+    'Same-origin dynamic import with "no-referrer" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'dynamic-import-same-origin-referrer-checker-worker.js',
+      workerReferrerPolicy: 'origin',
+      fetchType: 'descendant-dynamic' },
+    'Same-origin dynamic import with "origin" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'dynamic-import-same-origin-referrer-checker-worker.js',
+      workerReferrerPolicy: 'same-origin',
+      fetchType: 'descendant-dynamic' },
+    'Same-origin dynamic import with "same-origin" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'dynamic-import-remote-origin-referrer-checker-worker.sub.js',
+      workerReferrerPolicy: 'no-referrer',
+      fetchType: 'descendant-dynamic' },
+    'Cross-origin dynamic import with "no-referrer" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'dynamic-import-remote-origin-referrer-checker-worker.sub.js',
+      workerReferrerPolicy: 'origin',
+      fetchType: 'descendant-dynamic' },
+    'Cross-origin dynamic import with "origin" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'dynamic-import-remote-origin-referrer-checker-worker.sub.js',
+      workerReferrerPolicy: 'same-origin',
+      fetchType: 'descendant-dynamic' },
+    'Cross-origin dynamic import with "same-origin" referrer policy.');
+</script>
diff --git a/testing/web-platform/tests/workers/modules/dedicated-worker-import.any.js b/testing/web-platform/tests/workers/modules/dedicated-worker-import.any.js
new file mode 100644
index 0000000000..d5bb6cccbe
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/dedicated-worker-import.any.js
@@ -0,0 +1,22 @@
+// META: script=/workers/modules/resources/import-test-cases.js
+
+// Starts a dedicated worker for |testCase.scriptURL| and waits until the list
+// of imported modules is sent from the worker. Passes if the list is equal to
+// |testCase.expectation|.
+function import_test(testCase) {
+  promise_test(async () => {
+    const worker = new Worker(testCase.scriptURL, { type: 'module' });
+    worker.postMessage('Send message for tests from main script.');
+    const msgEvent = await new Promise((resolve, reject) => {
+      worker.onmessage = resolve;
+      worker.onerror = error => {
+        const msg = error instanceof ErrorEvent ? error.message
+                                                : 'unknown error';
+        reject(msg);
+      };
+    });
+    assert_array_equals(msgEvent.data, testCase.expectation);
+  }, testCase.description);
+}
+
+testCases.forEach(import_test);
diff --git a/testing/web-platform/tests/workers/modules/dedicated-worker-options-credentials.html b/testing/web-platform/tests/workers/modules/dedicated-worker-options-credentials.html
new file mode 100644
index 0000000000..94916d7ff5
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/dedicated-worker-options-credentials.html
@@ -0,0 +1,304 @@
+<!DOCTYPE html>
+<title>DedicatedWorker: WorkerOptions 'credentials'</title>
+<meta name="timeout" content="long">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script>
+host_info = get_host_info();
+
+// Determines the expected cookie value to be reported by a dedicated worker
+// based on the given option. The worker reports an empty string as the actual
+// cookie value if the cookie wasn't sent to the server. Otherwise, it's the
+// value set by the headers file:
+// "dedicated-worker-options-credentials.html.headers"
+function DetermineExpectedCookieValue(options, config) {
+  // Valid WorkerOptions and test config checking.
+  if (config.origin !== 'same' && config.origin !== 'remote')
+    assert_unreached('Invalid config.origin was specified: ' + config.origin);
+  if (options.credentials && options.credentials !== 'omit' &&
+      options.credentials !== 'same-origin' &&
+      options.credentials !== 'include') {
+    assert_unreached('Invalid credentials option was specified: ' +
+                      options.credentials);
+  }
+  if (options.type !== 'classic' && options.type !== 'module')
+    assert_unreached('Invalid type option was specified: ' + options.type);
+
+  if (options.type === 'classic')
+    return (config.origin === 'same') ? '1' : '';
+
+  if (options.credentials === 'omit')
+    return '';
+  else if (options.credentials === 'include')
+    return '1';
+  else
+    return (config.origin === 'same') ? '1' : '';
+}
+
+// Runs a credentials test with the given WorkerOptions.
+//
+// |options| is a WorkerOptions dict.
+// |config| has options as follows:
+//
+//   config = {
+//     fetchType: 'top-level' or 'descendant-static' or 'descendant-dynamic'
+//     origin: 'remote' or 'same'
+//   };
+//
+// - |config.fetchType| indicates the type of script to load for the test.
+// - |config.origin| indicates same-origin-ness of the script to load.
+function credentials_test(options, config, description) {
+  promise_test(async () => {
+    let workerURL, origin = config.origin;
+    if (config.fetchType === 'top-level') {
+      workerURL = 'resources/postmessage-credentials.py';
+    } else if (config.fetchType === 'descendant-static') {
+      workerURL =
+        `resources/static-import-${origin}-origin-credentials-checker-worker.${origin === 'same' ? '' : 'sub.'}js`;
+    } else if (config.fetchType === 'descendant-dynamic') {
+      workerURL =
+        `resources/dynamic-import-${origin}-origin-credentials-checker-worker.${origin === 'same' ? '' : 'sub.'}js`;
+    } else {
+      assert_unreached('Invalid config.fetchType: ' + config.fetchType);
+    }
+
+    const worker = new Worker(workerURL, options);
+
+    // Wait until the worker sends the actual cookie value.
+    const msg_event = await new Promise(resolve => worker.onmessage = resolve);
+
+    const expectedCookieValue = DetermineExpectedCookieValue(options, config);
+    assert_equals(msg_event.data, expectedCookieValue);
+  }, description);
+}
+
+function init() {
+  // Same-origin cookie is set up in the .headers file in this directory.
+  promise_test(async () => {
+    return fetch(
+      `${host_info.HTTP_REMOTE_ORIGIN}/cookies/resources/set-cookie.py?name=COOKIE_NAME&path=/workers/modules/`,
+      {
+        mode: 'no-cors',
+        credentials: 'include'
+      });
+  }, 'Test initialization: setting up cross-origin cookie');
+}
+
+init();
+
+// Tests for module workers.
+
+credentials_test(
+    { type: 'module' },
+    { fetchType: 'top-level', origin: 'same' },
+    'new Worker() with type=module and default credentials option should ' +
+    'behave as credentials=same-origin and send the credentials');
+
+credentials_test(
+    { credentials: 'omit', type: 'module' },
+    { fetchType: 'top-level', origin: 'same' },
+    'new Worker() with type=module and credentials=omit should not send the ' +
+    'credentials');
+
+credentials_test(
+    { credentials: 'same-origin', type: 'module' },
+    { fetchType: 'top-level', origin: 'same' },
+    'new Worker() with type=module and credentials=same-origin should send ' +
+    'the credentials');
+
+credentials_test(
+    { credentials: 'include', type: 'module' },
+    { fetchType: 'top-level', origin: 'same' },
+    'new Worker() with type=module and credentials=include should send the ' +
+    'credentials');
+
+// Tests for module worker static imports.
+
+credentials_test(
+    { type: 'module' },
+    { fetchType: 'descendant-static', origin: 'same' },
+    'new Worker() with type=module and default credentials option should ' +
+    'behave as credentials=same-origin and send the credentials for ' +
+    'same-origin static imports');
+
+credentials_test(
+    { credentials: 'omit', type: 'module' },
+    { fetchType: 'descendant-static', origin: 'same' },
+    'new Worker() with type=module and credentials=omit should not send the ' +
+    'credentials for same-origin static imports');
+
+credentials_test(
+    { credentials: 'same-origin', type: 'module' },
+    { fetchType: 'descendant-static', origin: 'same' },
+    'new Worker() with type=module and credentials=same-origin should send ' +
+    'the credentials for same-origin static imports');
+
+credentials_test(
+    { credentials: 'include', type: 'module' },
+    { fetchType: 'descendant-static', origin: 'same' },
+    'new Worker() with type=module and credentials=include should send the ' +
+    'credentials for same-origin static imports');
+
+credentials_test(
+    { type: 'module' },
+    { fetchType: 'descendant-static', origin: 'remote' },
+    'new Worker() with type=module and default credentials option should ' +
+    'behave as credentials=same-origin and not send the credentials for ' +
+    'cross-origin static imports');
+
+credentials_test(
+    { credentials: 'omit', type: 'module' },
+    { fetchType: 'descendant-static', origin: 'remote' },
+    'new Worker() with type-module credentials=omit should not send the ' +
+    'credentials for cross-origin static imports');
+
+credentials_test(
+    { credentials: 'same-origin', type: 'module' },
+    { fetchType: 'descendant-static', origin: 'remote' },
+    'new Worker() with type=module and credentials=same-origin should not ' +
+    'send the credentials for cross-origin static imports');
+
+credentials_test(
+    { credentials: 'include', type: 'module' },
+    { fetchType: 'descendant-static', origin: 'remote' },
+    'new Worker() with type=module and credentials=include should send the ' +
+    'credentials for cross-origin static imports');
+
+// Tests for module worker dynamic imports.
+
+credentials_test(
+    { type: 'module' },
+    { fetchType: 'descendant-dynamic', origin: 'same' },
+    'new Worker() with type=module and default credentials option should ' +
+    'behave as credentials=same-origin and send the credentials for ' +
+    'same-origin dynamic imports');
+
+credentials_test(
+    { credentials: 'omit', type: 'module' },
+    { fetchType: 'descendant-dynamic', origin: 'same' },
+    'new Worker() with type=module and credentials=omit should not send the ' +
+    'credentials for same-origin dynamic imports');
+
+credentials_test(
+    { credentials: 'same-origin', type: 'module' },
+    { fetchType: 'descendant-dynamic', origin: 'same' },
+    'new Worker() with type=module and credentials=same-origin should send ' +
+    'the credentials for same-origin dynamic imports');
+
+credentials_test(
+    { credentials: 'include', type: 'module' },
+    { fetchType: 'descendant-dynamic', origin: 'same' },
+    'new Worker() with type=module and credentials=include should send the ' +
+    'credentials for same-origin dynamic imports');
+
+credentials_test(
+    { type: 'module'},
+    { fetchType: 'descendant-dynamic', origin: 'remote' },
+    'new Worker() with type=module and default credentials option should ' +
+    'behave as credentials=same-origin and not send the credentials for ' +
+    'cross-origin dynamic imports');
+
+credentials_test(
+    { credentials: 'omit', type: 'module' },
+    { fetchType: 'descendant-dynamic', origin: 'remote' },
+    'new Worker() with type-module credentials=omit should not send the ' +
+    'credentials for cross-origin dynamic imports');
+
+credentials_test(
+    { credentials: 'same-origin', type: 'module' },
+    { fetchType: 'descendant-dynamic', origin: 'remote' },
+    'new Worker() with type=module and credentials=same-origin should not ' +
+    'send the credentials for cross-origin dynamic imports');
+
+credentials_test(
+    { credentials: 'include', type: 'module' },
+    { fetchType: 'descendant-dynamic', origin: 'remote' },
+    'new Worker() with type=module and credentials=include should send the ' +
+    'credentials for cross-origin dynamic imports');
+
+// Tests for classic workers.
+// TODO(domfarolino): Maybe move classic worker tests up a directory?
+
+credentials_test(
+    { type: 'classic' },
+    { fetchType: 'top-level', origin: 'same' },
+    'new Worker() with type=classic should always send the credentials ' +
+    'regardless of the credentials option (default).');
+
+credentials_test(
+    { credentials: 'omit', type: 'classic' },
+    { fetchType: 'top-level', origin: 'same' },
+    'new Worker() with type=classic should always send the credentials ' +
+    'regardless of the credentials option (omit).');
+
+credentials_test(
+    { credentials: 'same-origin', type: 'classic' },
+    { fetchType: 'top-level', origin: 'same' },
+    'new Worker() with type=classic should always send the credentials ' +
+    'regardless of the credentials option (same-origin).');
+
+credentials_test(
+    { credentials: 'include', type: 'classic' },
+    { fetchType: 'top-level', origin: 'same' },
+    'new Worker() with type=classic should always send the credentials ' +
+    'regardless of the credentials option (include).');
+
+// Tests for classic worker dynamic imports.
+
+credentials_test(
+    { type: 'classic' },
+    { fetchType: 'descendant-dynamic', origin: 'same' },
+    'new Worker() with type=classic should always send the credentials for ' +
+    'same-origin dynamic imports regardless of the credentials option ' +
+    '(default).');
+
+credentials_test(
+    { credentials: 'omit', type: 'classic' },
+    { fetchType: 'descendant-dynamic', origin: 'same' },
+    'new Worker() with type=classic should always send the credentials for ' +
+    'same-origin dynamic imports regardless of the credentials option (omit).');
+
+credentials_test(
+    { credentials: 'same-origin', type: 'classic' },
+    { fetchType: 'descendant-dynamic', origin: 'same' },
+    'new Worker() with type=classic should always send the credentials for ' +
+    'same-origin dynamic imports regardless of the credentials option ' +
+    '(same-origin).');
+
+credentials_test(
+    { credentials: 'include', type: 'classic' },
+    { fetchType: 'descendant-dynamic', origin: 'same' },
+    'new Worker() with type=classic should always send the credentials for ' +
+    'same-origin dynamic imports regardless of the credentials option ' +
+    '(include).');
+
+credentials_test(
+    { type: 'classic' },
+    { fetchType: 'descendant-dynamic', origin: 'remote' },
+    'new Worker() with type=classic should never send the credentials for ' +
+    'cross-origin dynamic imports regardless of the credentials option ' +
+    '(default).');
+
+credentials_test(
+    { credentials: 'omit', type: 'classic' },
+    { fetchType: 'descendant-dynamic', origin: 'remote' },
+    'new Worker() with type=classic should never send the credentials for ' +
+    'cross-origin dynamic imports regardless of the credentials option ' +
+    '(omit).');
+
+credentials_test(
+    { credentials: 'same-origin', type: 'classic' },
+    { fetchType: 'descendant-dynamic', origin: 'remote' },
+    'new Worker() with type=classic should never send the credentials for ' +
+    'cross-origin dynamic imports regardless of the credentials option ' +
+    '(same-origin).');
+
+credentials_test(
+    { credentials: 'include', type: 'classic' },
+    { fetchType: 'descendant-dynamic', origin: 'remote' },
+    'new Worker() with type=classic should never send the credentials for ' +
+    'cross-origin dynamic imports regardless of the credentials option ' +
+    '(include).');
+
+</script>
diff --git a/testing/web-platform/tests/workers/modules/dedicated-worker-options-credentials.html.headers b/testing/web-platform/tests/workers/modules/dedicated-worker-options-credentials.html.headers
new file mode 100644
index 0000000000..8da851ab73
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/dedicated-worker-options-credentials.html.headers
@@ -0,0 +1,2 @@
+Set-Cookie: COOKIE_NAME=1
+Access-Control-Allow-Credentials: true
diff --git a/testing/web-platform/tests/workers/modules/dedicated-worker-options-type.html b/testing/web-platform/tests/workers/modules/dedicated-worker-options-type.html
new file mode 100644
index 0000000000..bb37a18f2c
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/dedicated-worker-options-type.html
@@ -0,0 +1,46 @@
+<!DOCTYPE html>
+<title>DedicatedWorker: WorkerOptions 'type'</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+
+promise_test(() => {
+  const worker = new Worker('resources/post-message-on-load-worker.js');
+  return new Promise(resolve => worker.onmessage = resolve)
+      .then(msg_event => assert_equals(msg_event.data, 'LOADED'));
+}, 'Test worker construction with the default worker type.');
+
+promise_test(() => {
+  const worker = new Worker('resources/post-message-on-load-worker.js',
+                            { type: 'classic' });
+  return new Promise(resolve => worker.onmessage = resolve)
+      .then(msg_event => assert_equals(msg_event.data, 'LOADED'));
+}, 'Test worker construction with the "classic" worker type.');
+
+promise_test(() => {
+  const worker = new Worker('resources/post-message-on-load-worker.js',
+                            { type: 'module' });
+  return new Promise(resolve => worker.onmessage = resolve)
+      .then(msg_event => assert_equals(msg_event.data, 'LOADED'));
+}, 'Test worker construction with the "module" worker type.');
+
+test(() => {
+  assert_throws_js(
+      TypeError,
+      () => {
+        new Worker('resources/post-message-on-load-worker.js', { type: '' });
+      },
+      'Worker construction with an empty type should throw an exception');
+}, 'Test worker construction with an empty worker type.');
+
+test(() => {
+  assert_throws_js(
+      TypeError,
+      () => {
+        new Worker('resources/post-message-on-load-worker.js',
+                   { type: 'unknown' });
+      },
+      'Worker construction with an unknown type should throw an exception');
+}, 'Test worker construction with an unknown worker type.');
+
+</script>
diff --git a/testing/web-platform/tests/workers/modules/dedicated-worker-parse-error-failure.html b/testing/web-platform/tests/workers/modules/dedicated-worker-parse-error-failure.html
new file mode 100644
index 0000000000..343bfe289f
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/dedicated-worker-parse-error-failure.html
@@ -0,0 +1,51 @@
+<!DOCTYPE html>
+<title>DedicatedWorker: parse error failure</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script> setup({allow_uncaught_exception: true}); </script>
+<script src="../support/check-error-arguments.js"></script>
+<script>
+
+// Check if module scripts are supported on dedicated workers. There is no
+// direct way to detect it, so we assume it's supported when static import is
+// available on the workers.
+//
+// This check is necessary to appropriately test parse error handling because
+// we need to distinguish the parse error invoked by unsupported "import" in
+// the top-level script from the parse error invoked by the statically imported
+// script which is the one we want to check in this test.
+promise_setup(async () => {
+  const scriptURL = 'resources/static-import-worker.js';
+  const worker = new Worker(scriptURL, { type: 'module' });
+  worker.postMessage('Send message for tests from main script.');
+  const supportsModuleWorkers = await new Promise((resolve, reject) => {
+    worker.onmessage = e => {
+      resolve(e.data.length == 1 && e.data[0] == 'export-on-load-script.js');
+    };
+    worker.onerror = () => resolve(false);
+  });
+  assert_implements(
+    supportsModuleWorkers,
+    "Static import must be supported on module dedicated worker to run this test."
+  );
+});
+
+promise_test(async () => {
+  const scriptURL = 'resources/syntax-error.js';
+  const worker = new Worker(scriptURL, { type: 'module' });
+  const args = await new Promise(resolve =>
+      worker.onerror = (...args) => resolve(args));
+  window.checkErrorArguments(args);
+}, 'Module worker construction for script with syntax error should dispatch ' +
+   'an event named error.');
+
+promise_test(async () => {
+  const scriptURL = 'resources/static-import-syntax-error.js';
+  const worker = new Worker(scriptURL, { type: 'module' });
+  const args = await new Promise(resolve =>
+      worker.onerror = (...args) => resolve(args));
+  window.checkErrorArguments(args);
+}, 'Static import on module worker for script with syntax error should ' +
+   'dispatch an event named error.');
+
+</script>
diff --git a/testing/web-platform/tests/workers/modules/resources/dynamic-import-and-then-static-import-worker.js b/testing/web-platform/tests/workers/modules/resources/dynamic-import-and-then-static-import-worker.js
new file mode 100644
index 0000000000..527702f551
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/dynamic-import-and-then-static-import-worker.js
@@ -0,0 +1,32 @@
+// This script is meant to be imported by a module worker. It receives a
+// message from the worker and responds with the list of imported modules.
+const sourcePromise = new Promise(resolve => {
+  if ('DedicatedWorkerGlobalScope' in self &&
+      self instanceof DedicatedWorkerGlobalScope) {
+    self.onmessage = e => {
+      resolve(e.target);
+    };
+  } else if (
+      'SharedWorkerGlobalScope' in self &&
+      self instanceof SharedWorkerGlobalScope) {
+    self.onconnect = e => {
+      resolve(e.ports[0]);
+    };
+  } else if (
+      'ServiceWorkerGlobalScope' in self &&
+      self instanceof ServiceWorkerGlobalScope) {
+    self.onmessage = e => {
+      resolve(e.source);
+    };
+  }
+});
+
+const importedModulesPromise =
+  import('./export-on-static-import-script.js')
+    .then(module => module.importedModules)
+    .catch(error => `Failed to do dynamic import: ${error}`);
+
+Promise.all([sourcePromise, importedModulesPromise]).then(results => {
+  const [source, importedModules] = results;
+  source.postMessage(importedModules);
+});
diff --git a/testing/web-platform/tests/workers/modules/resources/dynamic-import-data-url-block-cross-origin.js b/testing/web-platform/tests/workers/modules/resources/dynamic-import-data-url-block-cross-origin.js
new file mode 100644
index 0000000000..caa15319c5
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/dynamic-import-data-url-block-cross-origin.js
@@ -0,0 +1,24 @@
+const sourcePromise = new Promise(resolve => {
+  if ('DedicatedWorkerGlobalScope' in self &&
+      self instanceof DedicatedWorkerGlobalScope) {
+    self.onmessage = e => {
+      resolve(e.target);
+    };
+  } else if (
+      'SharedWorkerGlobalScope' in self &&
+      self instanceof SharedWorkerGlobalScope) {
+    self.onconnect = e => {
+      resolve(e.ports[0]);
+    };
+  }
+});
+
+const importedModulesPromise =
+  import("data:text/javascript, export const importedModules = ['export-block-cross-origin.js'];")
+    .then(module => module.importedModules)
+    .catch(() => ['ERROR']);
+
+Promise.all([sourcePromise, importedModulesPromise]).then(results => {
+  const [source, importedModules] = results;
+  source.postMessage(importedModules);
+});
diff --git a/testing/web-platform/tests/workers/modules/resources/dynamic-import-given-url-worker.js b/testing/web-platform/tests/workers/modules/resources/dynamic-import-given-url-worker.js
new file mode 100644
index 0000000000..5510275935
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/dynamic-import-given-url-worker.js
@@ -0,0 +1,21 @@
+// This worker dynamically imports the script URL sent by postMessage(), and
+// sends back an error name if the dynamic import fails.
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  self.onmessage = msg_event => {
+    import(msg_event.data)
+        .then(module => postMessage(module.meta_url))
+        .catch(e => postMessage(e.name));
+  };
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  self.onconnect = connect_event => {
+    const port = connect_event.ports[0];
+    port.onmessage = msg_event => {
+      import(msg_event.data)
+          .then(module => port.postMessage(module.meta_url))
+          .catch(e => port.postMessage(e.name));
+    };
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/dynamic-import-remote-origin-credentials-checker-worker.sub.js b/testing/web-platform/tests/workers/modules/resources/dynamic-import-remote-origin-credentials-checker-worker.sub.js
new file mode 100644
index 0000000000..3cfbe7c6e4
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/dynamic-import-remote-origin-credentials-checker-worker.sub.js
@@ -0,0 +1,15 @@
+// Import a remote origin script.
+const import_url =
+    'http://{{domains[www1]}}:{{ports[http][0]}}/workers/modules/resources/export-credentials.py';
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  import(import_url)
+      .then(module => postMessage(module.cookie));
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  onconnect = e => {
+    import(import_url)
+        .then(module => e.ports[0].postMessage(module.cookie));
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/dynamic-import-remote-origin-referrer-checker-worker.sub.js b/testing/web-platform/tests/workers/modules/resources/dynamic-import-remote-origin-referrer-checker-worker.sub.js
new file mode 100644
index 0000000000..3f281faa7c
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/dynamic-import-remote-origin-referrer-checker-worker.sub.js
@@ -0,0 +1,16 @@
+// Import a remote origin script.
+const import_url = 'https://{{domains[www1]}}:{{ports[https][0]}}/workers/modules/resources/export-referrer-checker.py';
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  import(import_url)
+      .then(module => postMessage(module.referrer))
+      .catch(error => postMessage(`Import failed: ${error}`));
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  onconnect = e => {
+    import(import_url)
+        .then(module => e.ports[0].postMessage(module.referrer))
+        .catch(error => e.ports[0].postMessage(`Import failed: ${error}`));
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/dynamic-import-remote-origin-script-worker.sub.js b/testing/web-platform/tests/workers/modules/resources/dynamic-import-remote-origin-script-worker.sub.js
new file mode 100644
index 0000000000..7ed6543890
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/dynamic-import-remote-origin-script-worker.sub.js
@@ -0,0 +1,17 @@
+// Import a remote origin script.
+const importUrl =
+    'https://{{domains[www1]}}:{{ports[https][0]}}/workers/modules/resources/export-on-load-script.js';
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  import(importUrl)
+      .then(module => postMessage(module.importedModules))
+      .catch(e => postMessage(['ERROR']));
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  onconnect = e => {
+    import(importUrl)
+        .then(module => e.ports[0].postMessage(module.importedModules))
+        .catch(error => e.ports[0].postMessage(['ERROR']));
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/dynamic-import-same-origin-credentials-checker-worker.js b/testing/web-platform/tests/workers/modules/resources/dynamic-import-same-origin-credentials-checker-worker.js
new file mode 100644
index 0000000000..24dbd55128
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/dynamic-import-same-origin-credentials-checker-worker.js
@@ -0,0 +1,13 @@
+const import_url = './export-credentials.py';
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  import(import_url)
+      .then(module => postMessage(module.cookie));
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  onconnect = e => {
+    import(import_url)
+        .then(module => e.ports[0].postMessage(module.cookie));
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/dynamic-import-same-origin-referrer-checker-worker.js b/testing/web-platform/tests/workers/modules/resources/dynamic-import-same-origin-referrer-checker-worker.js
new file mode 100644
index 0000000000..56f8a6ffe8
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/dynamic-import-same-origin-referrer-checker-worker.js
@@ -0,0 +1,15 @@
+const import_url = './export-referrer-checker.py';
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  import(import_url)
+      .then(module => postMessage(module.referrer))
+      .catch(error => postMessage(`Import failed: ${error}`));
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  onconnect = e => {
+    import(import_url)
+        .then(module => e.ports[0].postMessage(module.referrer))
+        .catch(error => e.ports[0].postMessage(`Import failed: ${error}`));
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/dynamic-import-script-block-cross-origin.js b/testing/web-platform/tests/workers/modules/resources/dynamic-import-script-block-cross-origin.js
new file mode 100644
index 0000000000..52ec530663
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/dynamic-import-script-block-cross-origin.js
@@ -0,0 +1,24 @@
+const sourcePromise = new Promise(resolve => {
+  if ('DedicatedWorkerGlobalScope' in self &&
+      self instanceof DedicatedWorkerGlobalScope) {
+    self.onmessage = e => {
+      resolve(e.target);
+    };
+  } else if (
+      'SharedWorkerGlobalScope' in self &&
+      self instanceof SharedWorkerGlobalScope) {
+    self.onconnect = e => {
+      resolve(e.ports[0]);
+    };
+  }
+});
+
+const importedModulesPromise =
+  import('./export-block-cross-origin.js')
+    .then(module => module.importedModules)
+    .catch(() => ['ERROR']);
+
+Promise.all([sourcePromise, importedModulesPromise]).then(results => {
+  const [source, importedModules] = results;
+  source.postMessage(importedModules);
+});
diff --git a/testing/web-platform/tests/workers/modules/resources/dynamic-import-worker.js b/testing/web-platform/tests/workers/modules/resources/dynamic-import-worker.js
new file mode 100644
index 0000000000..2e756fe055
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/dynamic-import-worker.js
@@ -0,0 +1,32 @@
+// This script is meant to be imported by a module worker. It receives a
+// message from the worker and responds with the list of imported modules.
+const sourcePromise = new Promise(resolve => {
+  if ('DedicatedWorkerGlobalScope' in self &&
+      self instanceof DedicatedWorkerGlobalScope) {
+    self.onmessage = e => {
+      resolve(e.target);
+    };
+  } else if (
+      'SharedWorkerGlobalScope' in self &&
+      self instanceof SharedWorkerGlobalScope) {
+    self.onconnect = e => {
+      resolve(e.ports[0]);
+    };
+  } else if (
+      'ServiceWorkerGlobalScope' in self &&
+      self instanceof ServiceWorkerGlobalScope) {
+    self.onmessage = e => {
+      resolve(e.source);
+    };
+  }
+});
+
+const importedModulesPromise =
+  import('./export-on-load-script.js')
+    .then(module => module.importedModules)
+    .catch(error => `Failed to do dynamic import: ${error}`);
+
+Promise.all([sourcePromise, importedModulesPromise]).then(results => {
+  const [source, importedModules] = results;
+  source.postMessage(importedModules);
+});
diff --git a/testing/web-platform/tests/workers/modules/resources/empty-worker.js b/testing/web-platform/tests/workers/modules/resources/empty-worker.js
new file mode 100644
index 0000000000..49ceb2648a
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/empty-worker.js
@@ -0,0 +1 @@
+// Do nothing.
diff --git a/testing/web-platform/tests/workers/modules/resources/eval-dynamic-import-worker.js b/testing/web-platform/tests/workers/modules/resources/eval-dynamic-import-worker.js
new file mode 100644
index 0000000000..60080d4292
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/eval-dynamic-import-worker.js
@@ -0,0 +1,29 @@
+// This script is meant to be imported by a module worker. It receives a
+// message from the worker and responds with the list of imported modules.
+const code = 'const sourcePromise = new Promise(resolve => {' +
+    '  if (\'DedicatedWorkerGlobalScope\' in self &&' +
+    '      self instanceof DedicatedWorkerGlobalScope) {' +
+    '    self.onmessage = e => {' +
+    '      resolve(e.target);' +
+    '    };' +
+    '  } else if (\'SharedWorkerGlobalScope\' in self &&' +
+    '             self instanceof SharedWorkerGlobalScope) {' +
+    '    self.onconnect = e => {' +
+    '      resolve(e.ports[0]);' +
+    '    };' +
+    '  } else if (\'ServiceWorkerGlobalScope\' in self &&' +
+    '             self instanceof ServiceWorkerGlobalScope) {' +
+    '    self.onmessage = e => {' +
+    '      resolve(e.source);' +
+    '    };' +
+    '  }' +
+    '});' +
+    'const importedModulesPromise =' +
+    '  import(\'./export-on-load-script.js\')' +
+    '    .then(module => module.importedModules)' +
+    '    .catch(error => `Failed to do dynamic import: ${error}`);' +
+    'Promise.all([sourcePromise, importedModulesPromise]).then(results => {' +
+    '  const [source, importedModules] = results;' +
+    '  source.postMessage(importedModules);' +
+    '});';
+eval(code);
diff --git a/testing/web-platform/tests/workers/modules/resources/export-block-cross-origin.js b/testing/web-platform/tests/workers/modules/resources/export-block-cross-origin.js
new file mode 100644
index 0000000000..a4b513d280
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/export-block-cross-origin.js
@@ -0,0 +1 @@
+export const importedModules = ['export-block-cross-origin.js'];
diff --git a/testing/web-platform/tests/workers/modules/resources/export-credentials.py b/testing/web-platform/tests/workers/modules/resources/export-credentials.py
new file mode 100644
index 0000000000..3d0ba778d1
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/export-credentials.py
@@ -0,0 +1,15 @@
+def main(request, response):
+    cookie = request.cookies.first(b"COOKIE_NAME", None)
+
+    response_headers = [(b"Content-Type", b"text/javascript"),
+                        (b"Access-Control-Allow-Credentials", b"true")]
+
+    origin = request.headers.get(b"Origin", None)
+    if origin:
+        response_headers.append((b"Access-Control-Allow-Origin", origin))
+
+    cookie_value = b'';
+    if cookie:
+        cookie_value = cookie.value;
+    return (200, response_headers,
+            b"export const cookie = '"+cookie_value+b"';")
diff --git a/testing/web-platform/tests/workers/modules/resources/export-on-dynamic-import-script.js b/testing/web-platform/tests/workers/modules/resources/export-on-dynamic-import-script.js
new file mode 100644
index 0000000000..bab7cb48d2
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/export-on-dynamic-import-script.js
@@ -0,0 +1,8 @@
+// Export the list of imported modules. It's available after the |ready| promise
+// is resolved.
+export let importedModules = ['export-on-dynamic-import-script.js'];
+export let ready = import('./export-on-load-script.js')
+  .then(module => {
+    Array.prototype.push.apply(importedModules, module.importedModules);
+    return importedModules;
+  });
diff --git a/testing/web-platform/tests/workers/modules/resources/export-on-dynamic-import-script.js.headers b/testing/web-platform/tests/workers/modules/resources/export-on-dynamic-import-script.js.headers
new file mode 100644
index 0000000000..cb762eff80
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/export-on-dynamic-import-script.js.headers
@@ -0,0 +1 @@
+Access-Control-Allow-Origin: *
diff --git a/testing/web-platform/tests/workers/modules/resources/export-on-load-script.js b/testing/web-platform/tests/workers/modules/resources/export-on-load-script.js
new file mode 100644
index 0000000000..7d1b122c32
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/export-on-load-script.js
@@ -0,0 +1 @@
+export const importedModules = ['export-on-load-script.js'];
diff --git a/testing/web-platform/tests/workers/modules/resources/export-on-load-script.js.headers b/testing/web-platform/tests/workers/modules/resources/export-on-load-script.js.headers
new file mode 100644
index 0000000000..cb762eff80
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/export-on-load-script.js.headers
@@ -0,0 +1 @@
+Access-Control-Allow-Origin: *
diff --git a/testing/web-platform/tests/workers/modules/resources/export-on-load-script.py b/testing/web-platform/tests/workers/modules/resources/export-on-load-script.py
new file mode 100644
index 0000000000..9014341915
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/export-on-load-script.py
@@ -0,0 +1,15 @@
+import datetime
+
+def main(request, response):
+    # This script serves both preflight and main GET request for cross-origin
+    # static imports from module service workers.
+    # According to https://w3c.github.io/ServiceWorker/#update-algorithm,
+    # `Service-Worker: script` request header is added, which triggers CORS
+    # preflight.
+    response_headers = [(b"Content-Type", b"text/javascript"),
+                        (b"Access-Control-Allow-Origin", b"*"),
+                        (b"Access-Control-Allow-Headers", b"Service-Worker")]
+
+    body = b"export const importedModules = ['export-on-load-script.js'];"
+    body += b"// %d" % datetime.datetime.now().timestamp()
+    return (200, response_headers, body)
diff --git a/testing/web-platform/tests/workers/modules/resources/export-on-static-import-script.js b/testing/web-platform/tests/workers/modules/resources/export-on-static-import-script.js
new file mode 100644
index 0000000000..3f7174eef0
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/export-on-static-import-script.js
@@ -0,0 +1,3 @@
+import * as module from './export-on-load-script.js';
+const filename = 'export-on-static-import-script.js';
+export const importedModules = [filename].concat(module.importedModules);
diff --git a/testing/web-platform/tests/workers/modules/resources/export-on-static-import-script.js.headers b/testing/web-platform/tests/workers/modules/resources/export-on-static-import-script.js.headers
new file mode 100644
index 0000000000..cb762eff80
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/export-on-static-import-script.js.headers
@@ -0,0 +1 @@
+Access-Control-Allow-Origin: *
diff --git a/testing/web-platform/tests/workers/modules/resources/export-referrer-checker.py b/testing/web-platform/tests/workers/modules/resources/export-referrer-checker.py
new file mode 100644
index 0000000000..3b0fda1aa6
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/export-referrer-checker.py
@@ -0,0 +1,9 @@
+# Returns a worker script that posts the request's referrer header.
+def main(request, response):
+    referrer = request.headers.get(b"referer", b"")
+
+    response_headers = [(b"Content-Type", b"text/javascript"),
+                        (b"Access-Control-Allow-Origin", b"*")]
+
+    return (200, response_headers,
+            b"export const referrer = '"+referrer+b"';")
diff --git a/testing/web-platform/tests/workers/modules/resources/import-meta-url-export.js b/testing/web-platform/tests/workers/modules/resources/import-meta-url-export.js
new file mode 100644
index 0000000000..5287b2e9e8
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/import-meta-url-export.js
@@ -0,0 +1 @@
+export const meta_url = import.meta.url;
diff --git a/testing/web-platform/tests/workers/modules/resources/import-meta-url-worker.js b/testing/web-platform/tests/workers/modules/resources/import-meta-url-worker.js
new file mode 100644
index 0000000000..7887836a6c
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/import-meta-url-worker.js
@@ -0,0 +1,10 @@
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  postMessage(import.meta.url);
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  self.onconnect = e => {
+    e.ports[0].postMessage(import.meta.url);
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/import-scripts-worker.js b/testing/web-platform/tests/workers/modules/resources/import-scripts-worker.js
new file mode 100644
index 0000000000..d85f573ffe
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/import-scripts-worker.js
@@ -0,0 +1,33 @@
+try {
+  importScripts('empty-worker.js');
+  if ('DedicatedWorkerGlobalScope' in self &&
+      self instanceof DedicatedWorkerGlobalScope) {
+    postMessage('LOADED');
+  } else if (
+      'SharedWorkerGlobalScope' in self &&
+      self instanceof SharedWorkerGlobalScope) {
+    onconnect = e => {
+      e.ports[0].postMessage('LOADED');
+    };
+  }
+} catch (e) {
+  // Post a message instead of propagating an ErrorEvent to the page because
+  // propagated event loses an error name.
+  //
+  // Step 1. "Let notHandled be the result of firing an event named error at the
+  // Worker object associated with the worker, using ErrorEvent, with the
+  // cancelable attribute initialized to true, the message, filename, lineno,
+  // and colno attributes initialized appropriately, and the error attribute
+  // initialized to null."
+  // https://html.spec.whatwg.org/multipage/workers.html#runtime-script-errors-2
+  if ('DedicatedWorkerGlobalScope' in self &&
+      self instanceof DedicatedWorkerGlobalScope) {
+    postMessage(e.name);
+  } else if (
+      'SharedWorkerGlobalScope' in self &&
+      self instanceof SharedWorkerGlobalScope) {
+    onconnect = connectEvent => {
+      connectEvent.ports[0].postMessage(e.name);
+    };
+  }
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/import-test-cases.js b/testing/web-platform/tests/workers/modules/resources/import-test-cases.js
new file mode 100644
index 0000000000..8ad89e8fda
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/import-test-cases.js
@@ -0,0 +1,59 @@
+const testCases = [
+    {
+        scriptURL: '/workers/modules/resources/static-import-worker.js',
+        expectation: ['export-on-load-script.js'],
+        description: 'Static import.'
+    },
+    {
+        scriptURL: '/workers/modules/resources/static-import-remote-origin-script-worker.sub.js',
+        expectation: ['export-on-load-script.js'],
+        description: 'Static import (cross-origin).'
+    },
+    {
+        scriptURL: '/workers/modules/resources/static-import-redirect-worker.js',
+        expectation: ['export-on-load-script.js'],
+        description: 'Static import (redirect).'
+    },
+    {
+        scriptURL: '/workers/modules/resources/nested-static-import-worker.js',
+        expectation: [
+            'export-on-static-import-script.js',
+            'export-on-load-script.js'
+        ],
+        description: 'Nested static import.'
+    },
+    {
+        scriptURL: '/workers/modules/resources/static-import-and-then-dynamic-import-worker.js',
+        expectation: [
+            'export-on-dynamic-import-script.js',
+            'export-on-load-script.js'
+        ],
+        description: 'Static import and then dynamic import.'
+    },
+    {
+        scriptURL: '/workers/modules/resources/dynamic-import-worker.js',
+        expectation: ['export-on-load-script.js'],
+        description: 'Dynamic import.'
+    },
+    {
+        scriptURL: '/workers/modules/resources/nested-dynamic-import-worker.js',
+        expectation: [
+            'export-on-dynamic-import-script.js',
+            'export-on-load-script.js'
+        ],
+        description: 'Nested dynamic import.'
+    },
+    {
+        scriptURL: '/workers/modules/resources/dynamic-import-and-then-static-import-worker.js',
+        expectation: [
+            'export-on-static-import-script.js',
+            'export-on-load-script.js'
+        ],
+        description: 'Dynamic import and then static import.'
+    },
+    {
+        scriptURL: '/workers/modules/resources/eval-dynamic-import-worker.js',
+        expectation: ['export-on-load-script.js'],
+        description: 'eval(import()).'
+    }
+];
diff --git a/testing/web-platform/tests/workers/modules/resources/nested-dynamic-import-worker.js b/testing/web-platform/tests/workers/modules/resources/nested-dynamic-import-worker.js
new file mode 100644
index 0000000000..00da43c5f0
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/nested-dynamic-import-worker.js
@@ -0,0 +1,34 @@
+// This script is meant to be imported by a module worker. It receives a
+// message from the worker and responds with the list of imported modules.
+
+const sourcePromise = new Promise(resolve => {
+  if ('DedicatedWorkerGlobalScope' in self &&
+      self instanceof DedicatedWorkerGlobalScope) {
+    self.onmessage = e => {
+      resolve(e.target);
+    };
+  } else if (
+      'SharedWorkerGlobalScope' in self &&
+      self instanceof SharedWorkerGlobalScope) {
+    self.onconnect = e => {
+      resolve(e.ports[0]);
+    };
+  } else if (
+      'ServiceWorkerGlobalScope' in self &&
+      self instanceof ServiceWorkerGlobalScope) {
+    self.onmessage = e => {
+      resolve(e.source);
+    };
+  }
+});
+
+const importedModulesPromise =
+  import('./export-on-dynamic-import-script.js')
+    .then(module => module.ready)
+    .then(importedModules => importedModules)
+    .catch(error => `Failed to do dynamic import: ${error}`);
+
+Promise.all([sourcePromise, importedModulesPromise]).then(results => {
+  const [source, importedModules] = results;
+  source.postMessage(importedModules);
+});
diff --git a/testing/web-platform/tests/workers/modules/resources/nested-static-import-worker.js b/testing/web-platform/tests/workers/modules/resources/nested-static-import-worker.js
new file mode 100644
index 0000000000..c3a9ff0b79
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/nested-static-import-worker.js
@@ -0,0 +1,21 @@
+// This script is meant to be imported by a module worker. It receives a
+// message from the worker and responds with the list of imported modules.
+import * as module from './export-on-static-import-script.js';
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  self.onmessage = e => {
+    e.target.postMessage(module.importedModules);
+  };
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  self.onconnect = e => {
+    e.ports[0].postMessage(module.importedModules);
+  };
+} else if (
+    'ServiceWorkerGlobalScope' in self &&
+    self instanceof ServiceWorkerGlobalScope) {
+  self.onmessage = e => {
+    e.source.postMessage(module.importedModules);
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/new-shared-worker-window.html b/testing/web-platform/tests/workers/modules/resources/new-shared-worker-window.html
new file mode 100644
index 0000000000..84564fd7b6
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/new-shared-worker-window.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<title>SharedWorker: new SharedWorker()</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+let worker;
+
+// Create a new shared worker for a given script url.
+window.onmessage = e => {
+  worker = new SharedWorker(e.data.scriptURL,
+                            { name: e.data.name, type: 'module' });
+  worker.port.onmessage = msg => window.opener.postMessage(msg.data, '*');
+  worker.onerror = err => {
+    window.opener.postMessage(['ERROR'], '*');
+    err.preventDefault();
+  };
+}
+window.opener.postMessage('LOADED', '*');
+</script>
diff --git a/testing/web-platform/tests/workers/modules/resources/new-worker-window.html b/testing/web-platform/tests/workers/modules/resources/new-worker-window.html
new file mode 100644
index 0000000000..32a89fae0e
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/new-worker-window.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<title>DedicatedWorker: new Worker()</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+let worker;
+
+// Creates a new dedicated worker for a given script url.
+window.onmessage = e => {
+  worker = new Worker(e.data, { type: 'module' });
+  worker.postMessage('start');
+  worker.onmessage = msg => window.opener.postMessage(msg.data, '*');
+  worker.onerror = err => {
+      window.opener.postMessage(['ERROR'], '*');
+      err.preventDefault();
+  };
+};
+window.opener.postMessage('LOADED', '*');
+</script>
diff --git a/testing/web-platform/tests/workers/modules/resources/post-message-on-load-worker.js b/testing/web-platform/tests/workers/modules/resources/post-message-on-load-worker.js
new file mode 100644
index 0000000000..e1c547ab6a
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/post-message-on-load-worker.js
@@ -0,0 +1,10 @@
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  postMessage('LOADED');
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  self.onconnect = e => {
+    e.ports[0].postMessage('LOADED');
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/postmessage-credentials.py b/testing/web-platform/tests/workers/modules/resources/postmessage-credentials.py
new file mode 100644
index 0000000000..a054a1a923
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/postmessage-credentials.py
@@ -0,0 +1,22 @@
+def main(request, response):
+    cookie = request.cookies.first(b"COOKIE_NAME", None)
+
+    response_headers = [(b"Content-Type", b"text/javascript"),
+                        (b"Access-Control-Allow-Credentials", b"true")]
+
+    origin = request.headers.get(b"Origin", None)
+    if origin:
+        response_headers.append((b"Access-Control-Allow-Origin", origin))
+
+    cookie_value = b'';
+    if cookie:
+        cookie_value = cookie.value;
+    return (200, response_headers,
+            b"if ('DedicatedWorkerGlobalScope' in self &&" +
+            b"    self instanceof DedicatedWorkerGlobalScope) {" +
+            b"  postMessage('"+cookie_value+b"');" +
+            b"} else if (" +
+            b"    'SharedWorkerGlobalScope' in self &&" +
+            b"    self instanceof SharedWorkerGlobalScope) {" +
+            b"  onconnect = e => e.ports[0].postMessage('"+cookie_value+b"');" +
+            b"}")
diff --git a/testing/web-platform/tests/workers/modules/resources/postmessage-referrer-checker.py b/testing/web-platform/tests/workers/modules/resources/postmessage-referrer-checker.py
new file mode 100644
index 0000000000..699af684a2
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/postmessage-referrer-checker.py
@@ -0,0 +1,16 @@
+# Returns a worker script that posts the request's referrer header.
+def main(request, response):
+    referrer = request.headers.get(b"referer", b"")
+
+    response_headers = [(b"Content-Type", b"text/javascript"),
+                        (b"Access-Control-Allow-Origin", b"*")]
+
+    return (200, response_headers,
+            b"if ('DedicatedWorkerGlobalScope' in self &&" +
+            b"    self instanceof DedicatedWorkerGlobalScope) {" +
+            b"  postMessage('"+referrer+b"');" +
+            b"} else if (" +
+            b"    'SharedWorkerGlobalScope' in self &&" +
+            b"    self instanceof SharedWorkerGlobalScope) {" +
+            b"  onconnect = e => e.ports[0].postMessage('"+referrer+b"');" +
+            b"}")
diff --git a/testing/web-platform/tests/workers/modules/resources/redirect.py b/testing/web-platform/tests/workers/modules/resources/redirect.py
new file mode 100644
index 0000000000..396bd4c4b2
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/redirect.py
@@ -0,0 +1,8 @@
+def main(request, response):
+    """Simple handler that causes redirection.
+    This is placed here to stay within the same directory during redirects,
+    to avoid issues like https://crbug.com/1136775.
+    """
+    response.status = 302
+    location = request.GET.first(b"location")
+    response.headers.set(b"Location", location)
diff --git a/testing/web-platform/tests/workers/modules/resources/static-import-and-then-dynamic-import-worker.js b/testing/web-platform/tests/workers/modules/resources/static-import-and-then-dynamic-import-worker.js
new file mode 100644
index 0000000000..2d857a2e90
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/static-import-and-then-dynamic-import-worker.js
@@ -0,0 +1,34 @@
+// This script is meant to be imported by a module worker. It receives a
+// message from the worker and responds with the list of imported modules.
+import * as module from './export-on-dynamic-import-script.js';
+
+const sourcePromise = new Promise(resolve => {
+  if ('DedicatedWorkerGlobalScope' in self &&
+      self instanceof DedicatedWorkerGlobalScope) {
+    self.onmessage = e => {
+      resolve(e.target);
+    };
+  } else if (
+      'SharedWorkerGlobalScope' in self &&
+      self instanceof SharedWorkerGlobalScope) {
+    self.onconnect = e => {
+      resolve(e.ports[0]);
+    };
+  } else if (
+      'ServiceWorkerGlobalScope' in self &&
+      self instanceof ServiceWorkerGlobalScope) {
+    self.onmessage = e => {
+      resolve(e.source);
+    };
+  }
+});
+
+export let importedModules = ['export-on-dynamic-import-script.js'];
+const importedModulesPromise = module.ready
+  .then(importedModules => importedModules)
+  .catch(error => `Failed to do dynamic import: ${error}`);
+
+Promise.all([sourcePromise, importedModulesPromise]).then(results => {
+  const [source, importedModules] = results;
+  source.postMessage(importedModules);
+});
diff --git a/testing/web-platform/tests/workers/modules/resources/static-import-data-url-block-cross-origin.js b/testing/web-platform/tests/workers/modules/resources/static-import-data-url-block-cross-origin.js
new file mode 100644
index 0000000000..833348d66c
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/static-import-data-url-block-cross-origin.js
@@ -0,0 +1,14 @@
+import * as module from "data:text/javascript, export const importedModules = ['export-block-cross-origin.js'];";
+
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  self.onmessage = e => {
+    e.target.postMessage(module.importedModules);
+  };
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  self.onconnect = e => {
+    e.ports[0].postMessage(module.importedModules);
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/static-import-non-existent-script-worker.js b/testing/web-platform/tests/workers/modules/resources/static-import-non-existent-script-worker.js
new file mode 100644
index 0000000000..16f70e9daf
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/static-import-non-existent-script-worker.js
@@ -0,0 +1 @@
+import './non-existent-script.js';
diff --git a/testing/web-platform/tests/workers/modules/resources/static-import-redirect-worker.js b/testing/web-platform/tests/workers/modules/resources/static-import-redirect-worker.js
new file mode 100644
index 0000000000..8434c1a34e
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/static-import-redirect-worker.js
@@ -0,0 +1,21 @@
+// This script is meant to be imported by a module worker. It receives a
+// message from the worker and responds with the list of imported modules.
+import * as module from './redirect.py?location=/workers/modules/resources/export-on-load-script.js';
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  self.onmessage = e => {
+    e.target.postMessage(module.importedModules);
+  };
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  self.onconnect = e => {
+    e.ports[0].postMessage(module.importedModules);
+  };
+} else if (
+    'ServiceWorkerGlobalScope' in self &&
+    self instanceof ServiceWorkerGlobalScope) {
+  self.onmessage = e => {
+    e.source.postMessage(module.importedModules);
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/static-import-remote-origin-credentials-checker-worker.sub.js b/testing/web-platform/tests/workers/modules/resources/static-import-remote-origin-credentials-checker-worker.sub.js
new file mode 100644
index 0000000000..c543cb4961
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/static-import-remote-origin-credentials-checker-worker.sub.js
@@ -0,0 +1,12 @@
+// Import a remote origin script.
+import * as module from 'http://{{domains[www1]}}:{{ports[http][0]}}/workers/modules/resources/export-credentials.py';
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  postMessage(module.cookie);
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  onconnect = e => {
+    e.ports[0].postMessage(module.cookie);
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/static-import-remote-origin-referrer-checker-worker.sub.js b/testing/web-platform/tests/workers/modules/resources/static-import-remote-origin-referrer-checker-worker.sub.js
new file mode 100644
index 0000000000..45fc5493c9
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/static-import-remote-origin-referrer-checker-worker.sub.js
@@ -0,0 +1,12 @@
+// Import a remote origin script.
+import * as module from 'https://{{domains[www1]}}:{{ports[https][0]}}/workers/modules/resources/export-referrer-checker.py';
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  postMessage(module.referrer);
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  onconnect = e => {
+    e.ports[0].postMessage(module.referrer);
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/static-import-remote-origin-script-worker.sub.js b/testing/web-platform/tests/workers/modules/resources/static-import-remote-origin-script-worker.sub.js
new file mode 100644
index 0000000000..6432dd5d80
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/static-import-remote-origin-script-worker.sub.js
@@ -0,0 +1,20 @@
+// Import a remote origin script.
+import * as module from 'https://{{domains[www1]}}:{{ports[https][0]}}/workers/modules/resources/export-on-load-script.py';
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  self.onmessage = e => {
+    e.target.postMessage(module.importedModules);
+  };
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  self.onconnect = e => {
+    e.ports[0].postMessage(module.importedModules);
+  };
+} else if (
+    'ServiceWorkerGlobalScope' in self &&
+    self instanceof ServiceWorkerGlobalScope) {
+  self.onmessage = e => {
+    e.source.postMessage(module.importedModules);
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/static-import-same-origin-credentials-checker-worker.js b/testing/web-platform/tests/workers/modules/resources/static-import-same-origin-credentials-checker-worker.js
new file mode 100644
index 0000000000..e83dc92070
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/static-import-same-origin-credentials-checker-worker.js
@@ -0,0 +1,11 @@
+import * as module from './export-credentials.py';
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  postMessage(module.cookie);
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  onconnect = e => {
+    e.ports[0].postMessage(module.cookie);
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/static-import-same-origin-referrer-checker-worker.js b/testing/web-platform/tests/workers/modules/resources/static-import-same-origin-referrer-checker-worker.js
new file mode 100644
index 0000000000..ffcab9e45f
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/static-import-same-origin-referrer-checker-worker.js
@@ -0,0 +1,11 @@
+import * as module from './export-referrer-checker.py';
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  postMessage(module.referrer);
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  onconnect = e => {
+    e.ports[0].postMessage(module.referrer);
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/static-import-script-block-cross-origin.js b/testing/web-platform/tests/workers/modules/resources/static-import-script-block-cross-origin.js
new file mode 100644
index 0000000000..82be8e7ce7
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/static-import-script-block-cross-origin.js
@@ -0,0 +1,14 @@
+import * as module from './export-block-cross-origin.js';
+
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  self.onmessage = e => {
+    e.target.postMessage(module.importedModules);
+  };
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  self.onconnect = e => {
+    e.ports[0].postMessage(module.importedModules);
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/static-import-syntax-error.js b/testing/web-platform/tests/workers/modules/resources/static-import-syntax-error.js
new file mode 100644
index 0000000000..3a20e792c4
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/static-import-syntax-error.js
@@ -0,0 +1 @@
+import * as module from './syntax-error.js';
diff --git a/testing/web-platform/tests/workers/modules/resources/static-import-worker.js b/testing/web-platform/tests/workers/modules/resources/static-import-worker.js
new file mode 100644
index 0000000000..19a347999d
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/static-import-worker.js
@@ -0,0 +1,21 @@
+// This script is meant to be imported by a module worker. It receives a
+// message from the worker and responds with the list of imported modules.
+import * as module from './export-on-load-script.js';
+if ('DedicatedWorkerGlobalScope' in self &&
+    self instanceof DedicatedWorkerGlobalScope) {
+  self.onmessage = e => {
+    e.target.postMessage(module.importedModules);
+  };
+} else if (
+    'SharedWorkerGlobalScope' in self &&
+    self instanceof SharedWorkerGlobalScope) {
+  self.onconnect = e => {
+    e.ports[0].postMessage(module.importedModules);
+  };
+} else if (
+    'ServiceWorkerGlobalScope' in self &&
+    self instanceof ServiceWorkerGlobalScope) {
+  self.onmessage = e => {
+    e.source.postMessage(module.importedModules);
+  };
+}
diff --git a/testing/web-platform/tests/workers/modules/resources/syntax-error.js b/testing/web-platform/tests/workers/modules/resources/syntax-error.js
new file mode 100644
index 0000000000..8c5c4df671
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/syntax-error.js
@@ -0,0 +1 @@
+1 + ;
diff --git a/testing/web-platform/tests/workers/modules/resources/throw.js b/testing/web-platform/tests/workers/modules/resources/throw.js
new file mode 100644
index 0000000000..3d876d43d9
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/resources/throw.js
@@ -0,0 +1 @@
+throw new Error('custom message');
diff --git a/testing/web-platform/tests/workers/modules/shared-worker-import-blob-url.window.js b/testing/web-platform/tests/workers/modules/shared-worker-import-blob-url.window.js
new file mode 100644
index 0000000000..a79d5725ad
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/shared-worker-import-blob-url.window.js
@@ -0,0 +1,26 @@
+// META: script=/workers/modules/resources/import-test-cases.js
+
+// Imports |testCase.scriptURL| on a shared worker loaded from a blob URL,
+// and waits until the list of imported modules is sent from the worker. Passes
+// if the list is equal to |testCase.expectation|.
+function import_blob_url_test(testCase) {
+  promise_test(async () => {
+    const importURL = new URL(testCase.scriptURL, location.href);
+    const blob =
+        new Blob([`import "${importURL}";`], {type: 'text/javascript'});
+    const blobURL = URL.createObjectURL(blob);
+    const worker = new SharedWorker(blobURL, {type: 'module'});
+    worker.port.postMessage('Send message for tests from main script.');
+    const msgEvent = await new Promise((resolve, reject) => {
+      worker.port.onmessage = resolve;
+      worker.onerror = error => {
+        const msg = error instanceof ErrorEvent ? error.message
+                                                : 'unknown error';
+        reject(msg);
+      };
+    });
+    assert_array_equals(msgEvent.data, testCase.expectation);
+  }, testCase.description);
+}
+
+testCases.forEach(import_blob_url_test);
diff --git a/testing/web-platform/tests/workers/modules/shared-worker-import-csp.html b/testing/web-platform/tests/workers/modules/shared-worker-import-csp.html
new file mode 100644
index 0000000000..c7ca37557a
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/shared-worker-import-csp.html
@@ -0,0 +1,128 @@
+<!DOCTYPE html>
+<title>SharedWorker: CSP for ES Modules</title>
+<meta name="timeout" content="long">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+
+// This Set is for checking a shared worker in each test is newly created.
+const existingWorkers = new Set();
+
+async function openWindow(url) {
+  const win = window.open(url, '_blank');
+  add_result_callback(() => win.close());
+  const msgEvent = await new Promise(resolve => window.onmessage = resolve);
+  assert_equals(msgEvent.data, 'LOADED');
+  return win;
+}
+
+function import_csp_test(
+    cspHeader, importType, expectedImportedModules, description) {
+  // Append CSP header to windowURL for static import tests since static import
+  // scripts should obey Window's CSP.
+  const windowURL = `resources/new-shared-worker-window.html` +
+      `${importType === 'static'
+          ? '?pipe=header(Content-Security-Policy, ' + cspHeader + ')'
+          : ''}`;
+  // Append CSP header to scriptURL for dynamic import tests since dynamic
+  // import scripts should obey SharedWorker script's responce's CSP.
+  const scriptURL = `${importType}-import-remote-origin-script-worker.sub.js` +
+      `${importType === 'dynamic'
+          ? '?pipe=header(Content-Security-Policy, ' + cspHeader + ')'
+          : ''}`;
+  promise_test(async () => {
+    // Open a window that has the given CSP header.
+    const win = await openWindow(windowURL);
+    // Construct a unique name for SharedWorker.
+    const name = `${cspHeader}_${importType}`;
+    const workerProperties = { scriptURL, name };
+    // Check if this shared worker is newly created.
+    assert_false(existingWorkers.has(workerProperties));
+    existingWorkers.add(workerProperties);
+
+    // Ask the window to start a shared worker with the given CSP header.
+    // The shared worker doesn't inherits the window's CSP header.
+    // https://w3c.github.io/webappsec-csp/#initialize-global-object-csp
+    win.postMessage(workerProperties, '*');
+    const msg_event = await new Promise(resolve => window.onmessage = resolve);
+    assert_array_equals(msg_event.data, expectedImportedModules);
+  }, description);
+}
+
+// Tests for static import.
+//
+// Static import should obey the worker-src directive and the script-src
+// directive. If the both directives are specified, the worker-src directive
+// should be prioritized.
+//
+// "The script-src directive acts as a default fallback for all script-like
+// destinations (including worker-specific destinations if worker-src is not
+// present)."
+// https://w3c.github.io/webappsec-csp/#directive-script-src
+
+import_csp_test(
+    "worker-src 'self' 'unsafe-inline'", "static",
+    ['ERROR'],
+    "worker-src 'self' directive should disallow cross origin static import.");
+
+import_csp_test(
+    "worker-src * 'unsafe-inline'", "static",
+    ["export-on-load-script.js"],
+    "worker-src * directive should allow cross origin static import.");
+
+import_csp_test(
+    "script-src 'self' 'unsafe-inline'", "static",
+    ['ERROR'],
+    "script-src 'self' directive should disallow cross origin static import.");
+
+import_csp_test(
+    "script-src * 'unsafe-inline'", "static",
+    ["export-on-load-script.js"],
+    "script-src * directive should allow cross origin static import.");
+
+import_csp_test(
+    "worker-src *; script-src 'self' 'unsafe-inline'", "static",
+    ["export-on-load-script.js"],
+    "worker-src * directive should override script-src 'self' directive and " +
+        "allow cross origin static import.");
+
+import_csp_test(
+    "worker-src 'self'; script-src * 'unsafe-inline'", "static",
+    ['ERROR'],
+    "worker-src 'self' directive should override script-src * directive and " +
+        "disallow cross origin static import.");
+
+// Tests for dynamic import.
+//
+// Dynamic import should obey SharedWorker script's CSP instead of parent
+// Window's CSP.
+//
+// Dynamic import should obey the script-src directive instead of the worker-src
+// directive according to the specs:
+//
+// Dynamic import has the "script" destination.
+// Step 3: "Fetch a single module script graph given url, ..., "script", ..."
+// https://html.spec.whatwg.org/multipage/webappapis.html#fetch-an-import()-module-script-graph
+//
+// The "script" destination should obey the script-src CSP directive.
+// "The script-src directive acts as a default fallback for all script-like
+// destinations (including worker-specific destinations if worker-src is not
+// present)."
+// https://w3c.github.io/webappsec-csp/#directive-script-src
+
+import_csp_test(
+    "script-src 'self' 'unsafe-inline'", "dynamic",
+    ['ERROR'],
+    "script-src 'self' directive should disallow cross origin dynamic import.");
+
+import_csp_test(
+    "script-src * 'unsafe-inline'", "dynamic",
+    ["export-on-load-script.js"],
+    "script-src * directive should allow cross origin dynamic import.");
+
+import_csp_test(
+    "worker-src 'self' 'unsafe-inline'", "dynamic",
+    ["export-on-load-script.js"],
+    "worker-src 'self' directive should not take effect on dynamic import.");
+
+</script>
diff --git a/testing/web-platform/tests/workers/modules/shared-worker-import-data-url-cross-origin.html b/testing/web-platform/tests/workers/modules/shared-worker-import-data-url-cross-origin.html
new file mode 100644
index 0000000000..3f22c5094d
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/shared-worker-import-data-url-cross-origin.html
@@ -0,0 +1,43 @@
+<!DOCTYPE html>
+<title>SharedWorker: ES modules for data URL workers</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+
+const import_from_data_url_worker_test = (importType, isDataURL, expectation) => {
+  promise_test(async () => {
+    const importURL = new URL(`resources/${importType}-import-` +
+        `${isDataURL ? 'data-url' : 'script'}-block-cross-origin.js`,
+        location.href) + '?pipe=header(Access-Control-Allow-Origin, *)';
+    const dataURL = `data:text/javascript,import "${importURL}";`;
+    const worker = new SharedWorker(dataURL, { type: 'module' });
+    worker.port.postMessage('Send message for tests from main script.');
+    const msgEvent =
+        await new Promise(resolve => worker.port.onmessage = resolve);
+    assert_array_equals(msgEvent.data,
+        expectation === 'blocked' ? ['ERROR']
+                                  : ['export-block-cross-origin.js']);
+  }, `${importType} import ${isDataURL ? 'data url' : 'script'} from data: ` +
+     `URL should be ${expectation}.`);
+}
+
+// Static import should obey the outside settings.
+// SecurityOrigin of the outside settings is decided by Window.
+import_from_data_url_worker_test('static', true, 'allowed');
+import_from_data_url_worker_test('static', false, 'allowed');
+
+
+// Dynamic import should obey the inside settings.
+// SecurityOrigin of the inside settings is a unique opaque origin.
+//
+// Data url script is cross-origin to the inside settings' SecurityOrigin, but
+// dynamic importing it is allowed.
+// https://fetch.spec.whatwg.org/#concept-main-fetch
+// Step 5: request’s current URL’s scheme is "data" [spec text]
+import_from_data_url_worker_test('dynamic', true, 'allowed');
+
+// Non-data url script is cross-origin to the inside settings' SecurityOrigin.
+// It should be blocked.
+import_from_data_url_worker_test('dynamic', false, 'blocked');
+
+</script>
diff --git a/testing/web-platform/tests/workers/modules/shared-worker-import-data-url.window.js b/testing/web-platform/tests/workers/modules/shared-worker-import-data-url.window.js
new file mode 100644
index 0000000000..6d54c0e232
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/shared-worker-import-data-url.window.js
@@ -0,0 +1,23 @@
+// META: script=/workers/modules/resources/import-test-cases.js
+
+// Imports |testCase.scriptURL| on a shared worker loaded from a data URL,
+// and waits until the list of imported modules is sent from the worker. Passes
+// if the list is equal to |testCase.expectation|.
+function import_data_url_test(testCase) {
+  promise_test(async () => {
+    // The Access-Control-Allow-Origin header is necessary because a worker
+    // loaded from a data URL has a null origin and import() on the worker
+    // without the header is blocked.
+    const importURL = new URL(testCase.scriptURL, location.href) +
+        '?pipe=header(Access-Control-Allow-Origin, *)';
+    const dataURL = `data:text/javascript,import "${importURL}";`;
+
+    const worker = new SharedWorker(dataURL, { type: 'module'});
+    worker.port.postMessage('Send message for tests from main script.');
+    const msgEvent =
+        await new Promise(resolve => worker.port.onmessage = resolve);
+    assert_array_equals(msgEvent.data, testCase.expectation);
+  }, testCase.description);
+}
+
+testCases.forEach(import_data_url_test);
diff --git a/testing/web-platform/tests/workers/modules/shared-worker-import-failure.html b/testing/web-platform/tests/workers/modules/shared-worker-import-failure.html
new file mode 100644
index 0000000000..14579ba762
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/shared-worker-import-failure.html
@@ -0,0 +1,67 @@
+<!DOCTYPE html>
+<title>SharedWorker: import failure</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script> setup({allow_uncaught_exception: true}); </script>
+<script>
+
+// TODO: Factor out the test cases into a separate file.
+// (like import-test-cases.js)
+
+// SharedWorkers doesn't fire error events when runtime script errors occur.
+//
+// "For shared workers, if the error is still not handled afterwards, the error
+// may be reported to a developer console." [spec text]
+// https://html.spec.whatwg.org/C/#runtime-script-errors-2
+
+promise_test(async () => {
+  const scriptURL = 'resources/import-scripts-worker.js';
+  const worker = new SharedWorker(scriptURL, { type: 'module' });
+  const msg_event =
+    await new Promise(resolve => worker.port.onmessage = resolve);
+  assert_equals(msg_event.data, 'TypeError');
+}, 'importScripts() on module worker should throw an exception.');
+
+promise_test(() => {
+  const scriptURL = 'resources/non-existent-worker.js';
+  const worker = new SharedWorker(scriptURL, { type: 'module' });
+  return new Promise(resolve => worker.onerror = resolve);
+}, 'Worker construction for non-existent script should dispatch an ' +
+   'ErrorEvent.');
+
+promise_test(() => {
+  const scriptURL = 'resources/static-import-non-existent-script-worker.js';
+  const worker = new SharedWorker(scriptURL, { type: 'module' });
+  return new Promise(resolve => worker.onerror = resolve);
+}, 'Static import for non-existent script should dispatch an ErrorEvent.');
+
+promise_test(async () => {
+  const scriptURL = './non-existent-worker.js';
+  const worker =
+      new SharedWorker('resources/dynamic-import-given-url-worker.js',
+                       { type: 'module' });
+  worker.port.postMessage(scriptURL);
+  const msg_event = await new Promise((resolve, reject) => {
+    worker.port.onmessage = resolve;
+    worker.onerror = error => {
+      const msg = error instanceof ErrorEvent ? error.message
+                                              : 'unknown error';
+      reject(msg);
+    };
+  });
+  assert_equals(msg_event.data, 'TypeError');
+}, 'Dynamic import for non-existent script should throw an exception.');
+
+test(() => {
+  const scriptURL = 'http://invalid:123$';
+  assert_throws_dom('SyntaxError',
+                    () => new SharedWorker(scriptURL, { type: 'module' }));
+}, 'SharedWorker construction for an invalid URL should throw an exception.');
+
+test(() => {
+  const scriptURL = 'file:///static-import-worker.js';
+  assert_throws_dom('SecurityError',
+                    () => new SharedWorker(scriptURL, { type: 'module' }));
+}, 'SharedWorker construction for a file URL should throw an exception.');
+
+</script>
diff --git a/testing/web-platform/tests/workers/modules/shared-worker-import-meta.html b/testing/web-platform/tests/workers/modules/shared-worker-import-meta.html
new file mode 100644
index 0000000000..e8e9b51f6a
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/shared-worker-import-meta.html
@@ -0,0 +1,49 @@
+<!DOCTYPE html>
+<title>SharedWorker: import.meta</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+
+promise_test(() => {
+  const script_url = 'resources/import-meta-url-worker.js';
+  const worker = new SharedWorker(script_url, { type: 'module' });
+  return new Promise((resolve, reject) => {
+        worker.port.onmessage = resolve;
+        worker.onerror = (error) => reject(error && error.message);
+      })
+      .then(msg_event => assert_true(msg_event.data.endsWith(script_url)));
+}, 'Test import.meta.url on the top-level module script.');
+
+promise_test(() => {
+  const script_url = 'import-meta-url-export.js';
+  const worker = new SharedWorker(
+      'resources/dynamic-import-given-url-worker.js',
+      { type: 'module' });
+  worker.port.postMessage('./' + script_url);
+  return new Promise((resolve, reject) => {
+        worker.port.onmessage = resolve;
+        worker.onerror = (error) => reject(error && error.message);
+      })
+      .then(msg_event => assert_true(msg_event.data.endsWith(script_url)));
+}, 'Test import.meta.url on the imported module script.');
+
+promise_test(() => {
+  const script_url = 'import-meta-url-export.js';
+  const worker = new SharedWorker(
+      'resources/dynamic-import-given-url-worker.js',
+      { type: 'module' });
+  worker.port.postMessage('./' + script_url);
+
+  return new Promise((resolve, reject) => {
+        worker.port.onmessage = resolve;
+        worker.onerror = (error) => reject(error && error.message);
+      })
+      .then(msg_event => assert_true(msg_event.data.endsWith(script_url)))
+      .then(() => {
+        worker.port.postMessage('./' + script_url + '#1');
+        return new Promise(resolve => worker.port.onmessage = resolve);
+      })
+      .then(msg_event => assert_true(msg_event.data.endsWith(script_url + "#1")));
+}, 'Test import.meta.url on the imported module script with a fragment.');
+
+</script>
diff --git a/testing/web-platform/tests/workers/modules/shared-worker-import-referrer.html b/testing/web-platform/tests/workers/modules/shared-worker-import-referrer.html
new file mode 100644
index 0000000000..1096fd2ad8
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/shared-worker-import-referrer.html
@@ -0,0 +1,259 @@
+<!DOCTYPE html>
+<title>SharedWorker: Referrer</title>
+<meta name="timeout" content="long" />
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+
+// This Set is for checking a shared worker in each test is newly created.
+const existingWorkers = new Set();
+
+async function openWindow(url) {
+  const win = window.open(url, '_blank');
+  add_result_callback(() => win.close());
+  const msg_event = await new Promise(resolve => window.onmessage = resolve);
+  assert_equals(msg_event.data, 'LOADED');
+  return win;
+}
+
+// Removes URL parameters from the given URL string and returns it.
+function removeParams(url_string) {
+  if (!url_string)
+    return url_string;
+  let url = new URL(url_string);
+  for (var key of url.searchParams.keys())
+    url.searchParams.delete(key);
+  return url.href;
+}
+
+// Generates a referrer given a fetchType, referrer policy, and a request URL
+// (used to determine whether request is remote-origin or not). This function
+// is used to generate expected referrers.
+function generateExpectedReferrer(referrerURL, referrerPolicy, requestURL) {
+  let generatedReferrer = "";
+  if (referrerPolicy === 'no-referrer')
+    generatedReferrer = "";
+  else if (referrerPolicy === 'origin')
+    generatedReferrer = new URL('resources/' + referrerURL, location.href).origin + '/';
+  else if (referrerPolicy === 'same-origin')
+    generatedReferrer = requestURL.includes('remote') ? "" : new URL('resources/' + referrerURL, location.href).href;
+  else
+    generatedReferrer = new URL('resources/' + referrerURL, location.href).href;
+
+  return generatedReferrer;
+}
+
+// Runs a referrer policy test with the given settings. This opens a new window
+// that starts a shared worker.
+//
+// |settings| has options as follows:
+//
+//   settings = {
+//     scriptURL: 'resources/referrer-checker.sub.js',
+//     windowReferrerPolicy: 'no-referrer',
+//     workerReferrerPolicy: 'same-origin',
+//     fetchType: 'top-level' or 'descendant-static' or 'descendant-dynamic'
+//   };
+//
+// - |scriptURL| is used for starting a new worker.
+// - |windowReferrerPolicy| is to set the ReferrerPolicy HTTP header of the
+//   window. This policy should be applied to top-level worker module script
+//   loading and static imports.
+// - |workerReferrerPolicy| is to set the ReferrerPolicy HTTP header of the
+//   worker. This policy should be applied to dynamic imports.
+// - |fetchType| indicates a script whose referrer will be tested.
+function import_referrer_test(settings, description) {
+  promise_test(async () => {
+    let windowURL = 'resources/new-shared-worker-window.html';
+    if (settings.windowReferrerPolicy) {
+      windowURL +=
+          `?pipe=header(Referrer-Policy, ${settings.windowReferrerPolicy})`;
+    }
+
+    let scriptURL = settings.scriptURL;
+    if (settings.workerReferrerPolicy) {
+      // 'sub' is necessary even if the |scriptURL| contains the '.sub'
+      // extension because the extension doesn't work with the 'pipe' parameter.
+      // See an issue on the WPT's repository:
+      // https://github.com/web-platform-tests/wpt/issues/9345
+      scriptURL +=
+          `?pipe=sub|header(Referrer-Policy, ${settings.workerReferrerPolicy})`;
+    }
+
+    const win = await openWindow(windowURL);
+    // Construct a unique name for SharedWorker.
+    const name = `${settings.scriptURL}_` +
+        `${settings.windowReferrerPolicy ? settings.windowReferrerPolicy
+                                         : settings.workerReferrerPolicy}` +
+        `_${settings.fetchType}`;
+    const workerProperties = { scriptURL, name };
+    // Check if this shared worker is newly created.
+    assert_false(existingWorkers.has(workerProperties));
+    existingWorkers.add(workerProperties);
+
+    win.postMessage(workerProperties, '*');
+    const msgEvent = await new Promise(resolve => window.onmessage = resolve);
+
+    // Generate the expected referrer, given:
+    //   - The fetchType of the test
+    //   - Referrer URL to be used
+    //   - Relevant referrer policy
+    //   - Request URL
+    let expectedReferrer;
+    if (settings.fetchType === 'top-level') {
+      // Top-level worker requests have their outgoing referrers set given their
+      // containing window's URL and referrer policy.
+      expectedReferrer = generateExpectedReferrer('new-shared-worker-window.html', settings.windowReferrerPolicy, settings.scriptURL);
+    } else if (settings.fetchType === 'descendant-static') {
+      // Static descendant script requests from a worker have their outgoing
+      // referrer set given their containing script's URL and containing
+      // window's referrer policy.
+
+      // In the below cases, the referrer URL and the request URLs are the same
+      // because the initial request (for the top-level worker script) should
+      // act as the referrer for future descendant requests.
+      expectedReferrer = generateExpectedReferrer(settings.scriptURL, settings.windowReferrerPolicy, settings.scriptURL);
+    } else if (settings.fetchType === 'descendant-dynamic') {
+      // Dynamic descendant script requests from a worker have their outgoing
+      // referrer set given their containing script's URL and referrer policy.
+      expectedReferrer = generateExpectedReferrer(settings.scriptURL, settings.workerReferrerPolicy, settings.scriptURL);
+    }
+
+    // Delete query parameters from the actual referrer to make it easy to match
+    // it with the expected referrer.
+    const actualReferrer = removeParams(msgEvent.data);
+
+    assert_equals(actualReferrer, expectedReferrer);
+  }, description);
+}
+
+// Tests for top-level worker module script loading.
+//
+// Top-level worker module scripts should inherit the containing window's
+// referrer policy when using the containing window's URL as the referrer.
+//
+// [Current document]
+// --(open)--> [Window] whose referrer policy is |windowReferrerPolicy|.
+//   --(new SharedWorker)--> [SharedWorker] should respect [windowReferrerPolicy|
+//                           when using [Window]'s URL as the referrer.
+
+import_referrer_test(
+    { scriptURL: 'postmessage-referrer-checker.py',
+      windowReferrerPolicy: 'no-referrer',
+      fetchType: 'top-level' },
+    'Same-origin top-level module script loading with "no-referrer" referrer ' +
+        'policy');
+
+import_referrer_test(
+    { scriptURL: 'postmessage-referrer-checker.py',
+      windowReferrerPolicy: 'origin',
+      fetchType: 'top-level' },
+    'Same-origin top-level module script loading with "origin" referrer ' +
+        'policy');
+
+import_referrer_test(
+    { scriptURL: 'postmessage-referrer-checker.py',
+      windowReferrerPolicy: 'same-origin',
+      fetchType: 'top-level' },
+    'Same-origin top-level module script loading with "same-origin" referrer ' +
+        'policy');
+
+// Tests for static imports.
+//
+// Static imports should inherit the containing window's referrer policy when
+// using the containing module script's URL as the referrer.
+// Note: This is subject to change in the future; see
+// https://github.com/w3c/webappsec-referrer-policy/issues/111.
+//
+// [Current document]
+// --(open)--> [Window] whose referrer policy is |windowReferrerPolicy|.
+//   --(new SharedWorker)--> [SharedWorker]
+//     --(static import)--> [Script] should respect |windowReferrerPolicy| when
+//                          using [SharedWorker]'s URL as the referrer.
+
+import_referrer_test(
+    { scriptURL: 'static-import-same-origin-referrer-checker-worker.js',
+      windowReferrerPolicy: 'no-referrer',
+      fetchType: 'descendant-static' },
+    'Same-origin static import with "no-referrer" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'static-import-same-origin-referrer-checker-worker.js',
+      windowReferrerPolicy: 'origin',
+      fetchType: 'descendant-static' },
+    'Same-origin static import with "origin" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'static-import-same-origin-referrer-checker-worker.js',
+      windowReferrerPolicy: 'same-origin',
+      fetchType: 'descendant-static' },
+    'Same-origin static import with "same-origin" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'static-import-remote-origin-referrer-checker-worker.sub.js',
+      windowReferrerPolicy: 'no-referrer',
+      fetchType: 'descendant-static' },
+    'Cross-origin static import with "no-referrer" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'static-import-remote-origin-referrer-checker-worker.sub.js',
+      windowReferrerPolicy: 'origin',
+      fetchType: 'descendant-static' },
+    'Cross-origin static import with "origin" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'static-import-remote-origin-referrer-checker-worker.sub.js',
+      windowReferrerPolicy: 'same-origin',
+      fetchType: 'descendant-static' },
+    'Cross-origin static import with "same-origin" referrer policy.');
+
+// Tests for dynamic imports.
+//
+// Dynamic imports should inherit the containing script's referrer policy if
+// set, and use the default referrer policy otherwise, when using the
+// containing script's URL as the referrer.
+//
+// [Current document]
+// --(open)--> [Window]
+//   --(new SharedWorker)--> [SharedWorker] whose referrer policy is
+//                           |workerReferrerPolicy|.
+//     --(dynamic import)--> [Script] should respect |workerReferrerPolicy| when
+//                           using [SharedWorker]'s URL as the referrer.
+
+import_referrer_test(
+    { scriptURL: 'dynamic-import-same-origin-referrer-checker-worker.js',
+      workerReferrerPolicy: 'no-referrer',
+      fetchType: 'descendant-dynamic' },
+    'Same-origin dynamic import with "no-referrer" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'dynamic-import-same-origin-referrer-checker-worker.js',
+      workerReferrerPolicy: 'origin',
+      fetchType: 'descendant-dynamic' },
+    'Same-origin dynamic import with "origin" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'dynamic-import-same-origin-referrer-checker-worker.js',
+      workerReferrerPolicy: 'same-origin',
+      fetchType: 'descendant-dynamic' },
+    'Same-origin dynamic import with "same-origin" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'dynamic-import-remote-origin-referrer-checker-worker.sub.js',
+      workerReferrerPolicy: 'no-referrer',
+      fetchType: 'descendant-dynamic' },
+    'Cross-origin dynamic import with "no-referrer" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'dynamic-import-remote-origin-referrer-checker-worker.sub.js',
+      workerReferrerPolicy: 'origin',
+      fetchType: 'descendant-dynamic' },
+    'Cross-origin dynamic import with "origin" referrer policy.');
+
+import_referrer_test(
+    { scriptURL: 'dynamic-import-remote-origin-referrer-checker-worker.sub.js',
+      workerReferrerPolicy: 'same-origin',
+      fetchType: 'descendant-dynamic' },
+    'Cross-origin dynamic import with "same-origin" referrer policy.');
+
+</script>
diff --git a/testing/web-platform/tests/workers/modules/shared-worker-import.window.js b/testing/web-platform/tests/workers/modules/shared-worker-import.window.js
new file mode 100644
index 0000000000..5be49ec125
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/shared-worker-import.window.js
@@ -0,0 +1,22 @@
+// META: script=/workers/modules/resources/import-test-cases.js
+
+// Starts a shared worker for |testCase.scriptURL| and waits until the list
+// of imported modules is sent from the worker. Passes if the list is equal to
+// |testCase.expectation|.
+function import_test(testCase) {
+  promise_test(async () => {
+    const worker = new SharedWorker(testCase.scriptURL, {type: 'module'});
+    worker.port.postMessage('Send message for tests from main script.');
+    const msgEvent = await new Promise((resolve, reject) => {
+      worker.port.onmessage = resolve;
+      worker.onerror = error => {
+        const msg = error instanceof ErrorEvent ? error.message
+                                                : 'unknown error';
+        reject(msg);
+      };
+    });
+    assert_array_equals(msgEvent.data, testCase.expectation);
+  }, testCase.description);
+}
+
+testCases.forEach(import_test);
diff --git a/testing/web-platform/tests/workers/modules/shared-worker-options-credentials.html b/testing/web-platform/tests/workers/modules/shared-worker-options-credentials.html
new file mode 100644
index 0000000000..221dd01a37
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/shared-worker-options-credentials.html
@@ -0,0 +1,309 @@
+<!DOCTYPE html>
+<title>SharedWorker: WorkerOptions 'credentials'</title>
+<meta name="timeout" content="long">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script>
+host_info = get_host_info();
+
+// Determines the expected cookie value to be reported by a shared worker
+// based on the given option. The worker reports an empty string as the actual
+// cookie value if the cookie wasn't sent to the server. Otherwise, it's the
+// value set by the headers file:
+// "shared-worker-options-credentials.html.headers"
+function DetermineExpectedCookieValue(options, config) {
+  // Valid WorkerOptions and test config checking.
+  if (config.origin !== 'same' && config.origin !== 'remote')
+    assert_unreached('Invalid config.origin was specified: ' + config.origin);
+  if (options.credentials && options.credentials !== 'omit' &&
+      options.credentials !== 'same-origin' &&
+      options.credentials !== 'include') {
+    assert_unreached('Invalid credentials option was specified: ' +
+                      options.credentials);
+  }
+  if (options.type !== 'classic' && options.type !== 'module')
+    assert_unreached('Invalid type option was specified: ' + options.type);
+
+  if (options.type === 'classic')
+    return (config.origin === 'same') ? '1' : '';
+
+  if (options.credentials === 'omit')
+    return '';
+  else if (options.credentials === 'include')
+    return '1';
+  else
+    return (config.origin === 'same') ? '1' : '';
+}
+
+// Runs a credentials test with the given WorkerOptions.
+//
+// |options| is a WorkerOptions dict.
+// |config| has options as follows:
+//
+//   config = {
+//     fetchType: 'top-level' or 'descendant-static' or 'descendant-dynamic'
+//     origin: 'remote' or 'same'
+//   };
+//
+// - |config.fetchType| indicates the type of script to load for the test.
+// - |config.origin| indicates same-origin-ness of the script to load.
+function credentials_test(options, config, description) {
+  promise_test(async () => {
+    let workerURL, origin = config.origin;
+    if (config.fetchType === 'top-level') {
+      workerURL = 'resources/postmessage-credentials.py';
+    } else if (config.fetchType === 'descendant-static') {
+      workerURL =
+        `resources/static-import-${origin}-origin-credentials-checker-worker.${origin === 'same' ? '' : 'sub.'}js`;
+    } else if (config.fetchType === 'descendant-dynamic') {
+      workerURL =
+        `resources/dynamic-import-${origin}-origin-credentials-checker-worker.${origin === 'same' ? '' : 'sub.'}js`;
+    } else {
+      assert_unreached('Invalid config.fetchType: ' + config.fetchType);
+    }
+
+    // Name idetically for each test cases so that it connects to the shared
+    // worker with specified type and credentials.
+    options.name = `${options.type}_${options.credentials || 'default'}_${config.fetchType}_${config.origin}`;
+
+    const worker = new SharedWorker(workerURL, options);
+
+    // Wait until the worker sends the actual cookie value.
+    const msg_event = await new Promise(resolve => worker.port.onmessage = resolve);
+
+    const expectedCookieValue = DetermineExpectedCookieValue(options, config);
+    assert_equals(msg_event.data, expectedCookieValue);
+  }, description);
+}
+
+function init() {
+  // Same-origin cookie is set up in the .headers file in this directory.
+  promise_test(async () => {
+    return fetch(
+      `${host_info.HTTP_REMOTE_ORIGIN}/cookies/resources/set-cookie.py?name=COOKIE_NAME&path=/workers/modules/`,
+      {
+        mode: 'no-cors',
+        credentials: 'include'
+      });
+  }, 'Test initialization: setting up cross-origin cookie');
+}
+
+init();
+
+// Tests for module workers.
+
+credentials_test(
+    { type: 'module' },
+    { fetchType: 'top-level', origin: 'same' },
+    'new SharedWorker() with type=module and default credentials option ' +
+    'should behave as credentials=same-origin and send the credentials');
+
+credentials_test(
+    { credentials: 'omit', type: 'module' },
+    { fetchType: 'top-level', origin: 'same' },
+    'new SharedWorker() with type=module and credentials=omit should not ' +
+    'send the credentials');
+
+credentials_test(
+    { credentials: 'same-origin', type: 'module' },
+    { fetchType: 'top-level', origin: 'same' },
+    'new SharedWorker() with type=module and credentials=same-origin should ' +
+    'send the credentials');
+
+credentials_test(
+    { credentials: 'include', type: 'module' },
+    { fetchType: 'top-level', origin: 'same' },
+    'new SharedWorker() with type=module and credentials=include should send ' +
+    'the credentials');
+
+// Tests for module worker static imports.
+
+credentials_test(
+    { type: 'module' },
+    { fetchType: 'descendant-static', origin: 'same' },
+    'new SharedWorker() with type=module and default credentials option ' +
+    'should behave as credentials=same-origin and send the credentials for ' +
+    'same-origin static imports');
+
+credentials_test(
+    { credentials: 'omit', type: 'module' },
+    { fetchType: 'descendant-static', origin: 'same' },
+    'new SharedWorker() with type=module and credentials=omit should not ' +
+    'send the credentials for same-origin static imports');
+
+credentials_test(
+    { credentials: 'same-origin', type: 'module' },
+    { fetchType: 'descendant-static', origin: 'same' },
+    'new SharedWorker() with type=module and credentials=same-origin should ' +
+    'send the credentials for same-origin static imports');
+
+credentials_test(
+    { credentials: 'include', type: 'module' },
+    { fetchType: 'descendant-static', origin: 'same' },
+    'new SharedWorker() with type=module and credentials=include should send ' +
+    'the credentials for same-origin static imports');
+
+credentials_test(
+    { type: 'module' },
+    { fetchType: 'descendant-static', origin: 'remote' },
+    'new SharedWorker() with type=module and default credentials option ' +
+    'should behave as credentials=same-origin and not send the credentials ' +
+    'for cross-origin static imports');
+
+credentials_test(
+    { credentials: 'omit', type: 'module' },
+    { fetchType: 'descendant-static', origin: 'remote' },
+    'new SharedWorker() with type=module and credentials=omit should not ' +
+    'send the credentials for cross-origin static imports');
+
+credentials_test(
+    { credentials: 'same-origin', type: 'module' },
+    { fetchType: 'descendant-static', origin: 'remote' },
+    'new SharedWorker() with type=module and credentials=same-origin should ' +
+    'not send the credentials for cross-origin static imports');
+
+credentials_test(
+    { credentials: 'include', type: 'module' },
+    { fetchType: 'descendant-static', origin: 'remote' },
+    'new SharedWorker() with type=module and credentials=include should send ' +
+    'the credentials for cross-origin static imports');
+
+// Tests for module worker dynamic imports.
+
+credentials_test(
+    { type: 'module' },
+    { fetchType: 'descendant-dynamic', origin: 'same' },
+    'new SharedWorker() with type=module and default credentials option ' +
+    'should behave as credentials=same-origin and send the credentials for ' +
+    'same-origin dynamic imports');
+
+credentials_test(
+    { credentials: 'omit', type: 'module' },
+    { fetchType: 'descendant-dynamic', origin: 'same' },
+    'new SharedWorker() with type=module and credentials=omit should not ' +
+    'send the credentials for same-origin dynamic imports');
+
+credentials_test(
+    { credentials: 'same-origin', type: 'module' },
+    { fetchType: 'descendant-dynamic', origin: 'same' },
+    'new SharedWorker() with type=module and credentials=same-origin should ' +
+    'send the credentials for same-origin dynamic imports');
+
+credentials_test(
+    { credentials: 'include', type: 'module' },
+    { fetchType: 'descendant-dynamic', origin: 'same' },
+    'new SharedWorker() with type=module and credentials=include should send ' +
+    'the credentials for same-origin dynamic imports');
+
+credentials_test(
+    { type: 'module'},
+    { fetchType: 'descendant-dynamic', origin: 'remote' },
+    'new SharedWorker() with type=module and default credentials option ' +
+    'should behave as credentials=same-origin and not send the credentials ' +
+    'for cross-origin dynamic imports');
+
+credentials_test(
+    { credentials: 'omit', type: 'module' },
+    { fetchType: 'descendant-dynamic', origin: 'remote' },
+    'new SharedWorker() with type=module and credentials=omit should not ' +
+    'send the credentials for cross-origin dynamic imports');
+
+credentials_test(
+    { credentials: 'same-origin', type: 'module' },
+    { fetchType: 'descendant-dynamic', origin: 'remote' },
+    'new SharedWorker() with type=module and credentials=same-origin should ' +
+    'not send the credentials for cross-origin dynamic imports');
+
+credentials_test(
+    { credentials: 'include', type: 'module' },
+    { fetchType: 'descendant-dynamic', origin: 'remote' },
+    'new SharedWorker() with type=module and credentials=include should send ' +
+    'the credentials for cross-origin dynamic imports');
+
+// Tests for classic workers.
+// TODO(domfarolino): Maybe move classic worker tests up a directory?
+
+credentials_test(
+    { type: 'classic' },
+    { fetchType: 'top-level', origin: 'same' },
+    'new SharedWorker() with type=classic should always send the credentials ' +
+    'regardless of the credentials option (default).');
+
+credentials_test(
+    { credentials: 'omit', type: 'classic' },
+    { fetchType: 'top-level', origin: 'same' },
+    'new SharedWorker() with type=classic should always send the credentials ' +
+    'regardless of the credentials option (omit).');
+
+credentials_test(
+    { credentials: 'same-origin', type: 'classic' },
+    { fetchType: 'top-level', origin: 'same' },
+    'new SharedWorker() with type=classic should always send the credentials ' +
+    'regardless of the credentials option (same-origin).');
+
+credentials_test(
+    { credentials: 'include', type: 'classic' },
+    { fetchType: 'top-level', origin: 'same' },
+    'new SharedWorker() with type=classic should always send the credentials ' +
+    'regardless of the credentials option (include).');
+
+// Tests for classic worker dynamic imports.
+
+credentials_test(
+    { type: 'classic' },
+    { fetchType: 'descendant-dynamic', origin: 'same' },
+    'new SharedWorker() with type=classic should always send the credentials ' +
+    'for same-origin dynamic imports regardless of the credentials option ' +
+    '(default).');
+
+credentials_test(
+    { credentials: 'omit', type: 'classic' },
+    { fetchType: 'descendant-dynamic', origin: 'same' },
+    'new SharedWorker() with type=classic should always send the credentials ' +
+    'for same-origin dynamic imports regardless of the credentials option ' +
+    '(omit).');
+
+credentials_test(
+    { credentials: 'same-origin', type: 'classic' },
+    { fetchType: 'descendant-dynamic', origin: 'same' },
+    'new SharedWorker() with type=classic should always send the credentials ' +
+    'for same-origin dynamic imports regardless of the credentials option ' +
+    '(same-origin).');
+
+credentials_test(
+    { credentials: 'include', type: 'classic' },
+    { fetchType: 'descendant-dynamic', origin: 'same' },
+    'new SharedWorker() with type=classic should always send the credentials ' +
+    'for same-origin dynamic imports regardless of the credentials option ' +
+    '(include).');
+
+credentials_test(
+    { type: 'classic' },
+    { fetchType: 'descendant-dynamic', origin: 'remote' },
+    'new SharedWorker() with type=classic should never send the credentials ' +
+    'for cross-origin dynamic imports regardless of the credentials option ' +
+    '(default).');
+
+credentials_test(
+    { credentials: 'omit', type: 'classic' },
+    { fetchType: 'descendant-dynamic', origin: 'remote' },
+    'new SharedWorker() with type=classic should never send the credentials ' +
+    'for cross-origin dynamic imports regardless of the credentials option ' +
+    '(omit).');
+
+credentials_test(
+    { credentials: 'same-origin', type: 'classic' },
+    { fetchType: 'descendant-dynamic', origin: 'remote' },
+    'new SharedWorker() with type=classic should never send the credentials ' +
+    'for cross-origin dynamic imports regardless of the credentials option ' +
+    '(same-origin).');
+
+credentials_test(
+    { credentials: 'include', type: 'classic' },
+    { fetchType: 'descendant-dynamic', origin: 'remote' },
+    'new SharedWorker() with type=classic should never send the credentials ' +
+    'for cross-origin dynamic imports regardless of the credentials option ' +
+    '(include).');
+
+</script>
diff --git a/testing/web-platform/tests/workers/modules/shared-worker-options-credentials.html.headers b/testing/web-platform/tests/workers/modules/shared-worker-options-credentials.html.headers
new file mode 100644
index 0000000000..8da851ab73
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/shared-worker-options-credentials.html.headers
@@ -0,0 +1,2 @@
+Set-Cookie: COOKIE_NAME=1
+Access-Control-Allow-Credentials: true
diff --git a/testing/web-platform/tests/workers/modules/shared-worker-options-type.html b/testing/web-platform/tests/workers/modules/shared-worker-options-type.html
new file mode 100644
index 0000000000..f62eeeb76b
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/shared-worker-options-type.html
@@ -0,0 +1,48 @@
+<!DOCTYPE html>
+<title>SharedWorker: WorkerOptions 'type'</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+
+promise_test(() => {
+  const worker = new SharedWorker('resources/post-message-on-load-worker.js',
+                                  'default');
+  return new Promise(resolve => worker.port.onmessage = resolve)
+      .then(msg_event => assert_equals(msg_event.data, 'LOADED'));
+}, 'Test worker construction with the default worker type.');
+
+promise_test(() => {
+  const worker = new SharedWorker('resources/post-message-on-load-worker.js',
+                                  { name: 'classic', type: 'classic' });
+  return new Promise(resolve => worker.port.onmessage = resolve)
+      .then(msg_event => assert_equals(msg_event.data, 'LOADED'));
+}, 'Test worker construction with the "classic" worker type.');
+
+promise_test(() => {
+  const worker = new SharedWorker('resources/post-message-on-load-worker.js',
+                                  { name: 'module', type: 'module' });
+  return new Promise(resolve => worker.port.onmessage = resolve)
+      .then(msg_event => assert_equals(msg_event.data, 'LOADED'));
+}, 'Test worker construction with the "module" worker type.');
+
+test(() => {
+  assert_throws_js(
+      TypeError,
+      () => {
+        new SharedWorker('resources/post-message-on-load-worker.js',
+                         { name: 'blank', type : '' });
+      },
+      'Worker construction with an empty type should throw an exception');
+}, 'Test worker construction with an empty worker type.');
+
+test(() => {
+  assert_throws_js(
+      TypeError,
+      () => {
+        new SharedWorker('resources/post-message-on-load-worker.js',
+                         { name: 'unknown', type : 'unknown' });
+      },
+      'Worker construction with an unknown type should throw an exception');
+}, 'Test worker construction with an unknown worker type.');
+
+</script>
diff --git a/testing/web-platform/tests/workers/modules/shared-worker-parse-error-failure.html b/testing/web-platform/tests/workers/modules/shared-worker-parse-error-failure.html
new file mode 100644
index 0000000000..8f63d5f37a
--- /dev/null
+++ b/testing/web-platform/tests/workers/modules/shared-worker-parse-error-failure.html
@@ -0,0 +1,49 @@
+<!DOCTYPE html>
+<title>SharedWorker: parse error failure</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../support/check-error-arguments.js"></script>
+<script>
+
+// Check if module shared worker is supported.
+// In this test scope, we only use simple non-nested static import as a feature
+// of module shared worker, so we only check if static import is supported.
+//
+// This check is necessary to appropriately test parse error handling because
+// we need to distingusih the parse error invoked by unsupported "import" in
+// the top-level script from the parse error invoked by the statically imported
+// script which is the one we want to check in this test.
+promise_setup(async () => {
+  const scriptURL = 'resources/static-import-worker.js';
+  const worker = new SharedWorker(scriptURL, { type: 'module' });
+  const supportsModuleWorkers = await new Promise((resolve, reject) => {
+    worker.port.onmessage = e => {
+      resolve(e.data.length == 1 && e.data[0] == 'export-on-load-script.js');
+    };
+    worker.onerror = () => resolve(false);
+  });
+  assert_implements(
+    supportsModuleWorkers,
+    "Static import must be supported on module shared worker to run this test."
+  );
+});
+
+promise_test(async () => {
+  const scriptURL = 'resources/syntax-error.js';
+  const worker = new SharedWorker(scriptURL, { type: 'module' });
+  const args = await new Promise(resolve =>
+      worker.onerror = (...args) => resolve(args));
+  window.checkErrorArguments(args);
+}, 'Module shared worker construction for script with syntax error should ' +
+   'dispatch an event named error.');
+
+promise_test(async () => {
+  const scriptURL = 'resources/static-import-syntax-error.js';
+  const worker = new SharedWorker(scriptURL, { type: 'module' });
+  const args = await new Promise(resolve =>
+      worker.onerror = (...args) => resolve(args));
+  window.checkErrorArguments(args);
+}, 'Static import on module shared worker for script with syntax error ' +
+   'should dispatch an event named error.');
+
+</script>
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