1 files changed, 61 insertions, 0 deletions
diff --git a/toolkit/components/extensions/test/xpcshell/test_ext_contentscript_scriptCreated.js b/toolkit/components/extensions/test/xpcshell/test_ext_contentscript_scriptCreated.js
new file mode 100644
index 0000000000..2f10f8f252
--- /dev/null
+++ b/toolkit/components/extensions/test/xpcshell/test_ext_contentscript_scriptCreated.js
@@ -0,0 +1,61 @@
+"use strict";
+
+const server = createHttpServer();
+server.registerDirectory("/data/", do_get_file("data"));
+
+const BASE_URL = `http://localhost:${server.identity.primaryPort}/data`;
+
+// ExtensionContent.jsm needs to know when it's running from xpcshell,
+// to use the right timeout for content scripts executed at document_idle.
+ExtensionTestUtils.mockAppInfo();
+
+// Test that document_start content scripts don't block script-created
+// parsers.
+add_task(async function test_contentscript_scriptCreated() {
+  let extensionData = {
+    manifest: {
+      content_scripts: [
+        {
+          matches: ["http://*/*/file_document_write.html"],
+          js: ["content_script.js"],
+          run_at: "document_start",
+          match_about_blank: true,
+          all_frames: true,
+        },
+      ],
+    },
+
+    files: {
+      "content_script.js": function () {
+        if (window === top) {
+          addEventListener(
+            "message",
+            msg => {
+              browser.test.assertEq(
+                "ok",
+                msg.data,
+                "document.write() succeeded"
+              );
+              browser.test.sendMessage("content-script-done");
+            },
+            { once: true }
+          );
+        }
+      },
+    },
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+
+  await extension.startup();
+
+  let contentPage = await ExtensionTestUtils.loadContentPage(
+    `${BASE_URL}/file_document_write.html`
+  );
+
+  await extension.awaitMessage("content-script-done");
+
+  await contentPage.close();
+
+  await extension.unload();
+});