1 files changed, 55 insertions, 0 deletions
diff --git a/toolkit/components/extensions/test/xpcshell/test_ext_sandboxed_resource.js b/toolkit/components/extensions/test/xpcshell/test_ext_sandboxed_resource.js
new file mode 100644
index 0000000000..05489d753d
--- /dev/null
+++ b/toolkit/components/extensions/test/xpcshell/test_ext_sandboxed_resource.js
@@ -0,0 +1,55 @@
+"use strict";
+
+// Test that an extension page which is sandboxed may load resources
+// from itself without relying on web acessible resources.
+add_task(async function test_webext_background_sandbox_privileges() {
+  function backgroundSubframeScript() {
+    window.parent.postMessage(typeof browser, "*");
+  }
+
+  function backgroundScript() {
+    /* eslint-disable-next-line mozilla/balanced-listeners */
+    window.addEventListener("message", event => {
+      if (event.data == "undefined") {
+        browser.test.notifyPass("webext-background-sandbox-privileges");
+      } else {
+        browser.test.notifyFail("webext-background-sandbox-privileges");
+      }
+    });
+  }
+
+  let extensionData = {
+    manifest: {
+      background: {
+        page: "background.html",
+      },
+    },
+    files: {
+      "background.html": `<!DOCTYPE>
+        <html>
+          <head>
+            <meta charset="utf-8">
+          </head>
+          <body>
+            <script src="background.js"><\/script>
+            <iframe src="background-subframe.html" sandbox="allow-scripts"></iframe>
+          </body>
+        </html>`,
+      "background-subframe.html": `<!DOCTYPE>
+        <html>
+          <head>
+            <meta charset="utf-8">
+            <script src="background-subframe.js"><\/script>
+          </head>
+        </html>`,
+      "background-subframe.js": backgroundSubframeScript,
+      "background.js": backgroundScript,
+    },
+  };
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  await extension.startup();
+
+  await extension.awaitFinish("webext-background-sandbox-privileges");
+  await extension.unload();
+});