1 files changed, 52 insertions, 0 deletions
diff --git a/testing/web-platform/tests/workers/importscripts_mime.any.js b/testing/web-platform/tests/workers/importscripts_mime.any.js
new file mode 100644
index 0000000000..bfdfc191fd
--- /dev/null
+++ b/testing/web-platform/tests/workers/importscripts_mime.any.js
@@ -0,0 +1,52 @@
+// META: global=worker
+//
+// Tentative test for https://github.com/whatwg/html/issues/3255
+
+let test_cases = [
+  // Supported mimetypes:
+  ["text/javascript", true],
+  ["application/javascript", true],
+  ["text/ecmascript", true],
+
+  // Blocked mimetpyes:
+  ["image/png", false],
+  ["text/csv", false],
+  ["video/mpeg", false],
+
+  // Legacy mimetypes:
+  ["text/html", false],
+  ["text/plain", false],
+  ["application/xml", false],
+  ["application/octet-stream", false],
+
+  // Potato mimetypes:
+  ["text/potato", false],
+  ["potato/text", false],
+  ["aaa/aaa", false],
+  ["zzz/zzz", false],
+
+  // Parameterized mime types:
+  ["text/javascript; charset=utf-8", true],
+  ["text/javascript;charset=utf-8", true],
+  ["text/javascript;bla;bla", true],
+  ["text/csv; charset=utf-8", false],
+  ["text/csv;charset=utf-8", false],
+  ["text/csv;bla;bla", false],
+
+  // Funky capitalization:
+  ["Text/html", false],
+  ["text/Html", false],
+  ["TeXt/HtMl", false],
+  ["TEXT/HTML", false],
+];
+
+for (const [mimeType, isScriptType] of test_cases) {
+  test(t => {
+    let import_url = "/workers/support/imported_script.py?mime=" + mimeType;
+    if (isScriptType) {
+      assert_equals(undefined, importScripts(import_url));
+    } else {
+      assert_throws_dom("NetworkError", _ => { importScripts(import_url) })
+    }
+  }, "importScripts() requires scripty MIME types: " + mimeType + " is " + (isScriptType ? "allowed" : "blocked") + ".");
+}