1 files changed, 78 insertions, 0 deletions
diff --git a/toolkit/components/extensions/test/xpcshell/test_ext_contentscript_about_blank_start.js b/toolkit/components/extensions/test/xpcshell/test_ext_contentscript_about_blank_start.js
new file mode 100644
index 0000000000..1297f105a1
--- /dev/null
+++ b/toolkit/components/extensions/test/xpcshell/test_ext_contentscript_about_blank_start.js
@@ -0,0 +1,78 @@
+"use strict";
+
+const server = createHttpServer({ hosts: ["example.com"] });
+
+server.registerPathHandler("/blank-iframe.html", (request, response) => {
+  response.setStatusLine(request.httpVersion, 200, "OK");
+  response.setHeader("Content-Type", "text/html; charset=utf-8", false);
+  response.write("<iframe></iframe>");
+});
+
+add_task(async function content_script_at_document_start() {
+  let extensionData = {
+    manifest: {
+      content_scripts: [
+        {
+          matches: ["<all_urls>"],
+          js: ["start.js"],
+          run_at: "document_start",
+          match_about_blank: true,
+        },
+      ],
+    },
+
+    files: {
+      "start.js": function () {
+        browser.test.sendMessage("content-script-done");
+      },
+    },
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  await extension.startup();
+  let contentPage = await ExtensionTestUtils.loadContentPage(`about:blank`);
+  await extension.awaitMessage("content-script-done");
+  await contentPage.close();
+  await extension.unload();
+});
+
+add_task(async function content_style_at_document_start() {
+  let extensionData = {
+    manifest: {
+      content_scripts: [
+        {
+          matches: ["<all_urls>"],
+          css: ["start.css"],
+          run_at: "document_start",
+          match_about_blank: true,
+        },
+        {
+          matches: ["<all_urls>"],
+          js: ["end.js"],
+          run_at: "document_end",
+          match_about_blank: true,
+        },
+      ],
+    },
+
+    files: {
+      "start.css": "body { background: red; }",
+      "end.js": function () {
+        let style = window.getComputedStyle(document.body);
+        browser.test.assertEq(
+          "rgb(255, 0, 0)",
+          style.backgroundColor,
+          "document_start style should have been applied"
+        );
+        browser.test.sendMessage("content-script-done");
+      },
+    },
+  };
+
+  let extension = ExtensionTestUtils.loadExtension(extensionData);
+  await extension.startup();
+  let contentPage = await ExtensionTestUtils.loadContentPage(`about:blank`);
+  await extension.awaitMessage("content-script-done");
+  await contentPage.close();
+  await extension.unload();
+});