1 files changed, 75 insertions, 0 deletions
diff --git a/toolkit/components/extensions/test/xpcshell/test_ext_contentscript_xml_prettyprint.js b/toolkit/components/extensions/test/xpcshell/test_ext_contentscript_xml_prettyprint.js
new file mode 100644
index 0000000000..0682d30933
--- /dev/null
+++ b/toolkit/components/extensions/test/xpcshell/test_ext_contentscript_xml_prettyprint.js
@@ -0,0 +1,75 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+Services.prefs.setBoolPref("layout.xml.prettyprint", true);
+
+const BASE_XML = '<?xml version="1.0" encoding="UTF-8"?>';
+const server = createHttpServer({ hosts: ["example.com"] });
+
+server.registerPathHandler("/test.xml", (request, response) => {
+  response.setStatusLine(request.httpVersion, 200, "OK");
+  response.setHeader("Content-Type", "text/xml; charset=utf-8", false);
+  response.write(`${BASE_XML}\n<note></note>`);
+});
+
+// Make sure that XML pretty printer runs after content scripts
+// that runs at document_start (See Bug 1605657).
+add_task(async function content_script_on_xml_prettyprinted_document() {
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      content_scripts: [
+        {
+          matches: ["<all_urls>"],
+          js: ["start.js"],
+          run_at: "document_start",
+        },
+      ],
+    },
+    files: {
+      "start.js": async function () {
+        const el = document.createElement("ext-el");
+        document.documentElement.append(el);
+        if (document.readyState !== "complete") {
+          await new Promise(resolve => {
+            document.addEventListener("DOMContentLoaded", resolve, {
+              once: true,
+            });
+          });
+        }
+        browser.test.sendMessage("content-script-done");
+      },
+    },
+  });
+
+  await extension.startup();
+  let contentPage = await ExtensionTestUtils.loadContentPage(
+    "http://example.com/test.xml"
+  );
+
+  info("Wait content script and xml document to be fully loaded");
+  await extension.awaitMessage("content-script-done");
+
+  info("Verify the xml file is still pretty printed");
+  const res = await contentPage.spawn([], () => {
+    const doc = this.content.document;
+    const shadowRoot = doc.documentElement.openOrClosedShadowRoot;
+    const prettyPrintLink =
+      shadowRoot &&
+      shadowRoot.querySelector("link[href*='XMLPrettyPrint.css']");
+    return {
+      hasShadowRoot: !!shadowRoot,
+      hasPrettyPrintLink: !!prettyPrintLink,
+    };
+  });
+
+  Assert.deepEqual(
+    res,
+    { hasShadowRoot: true, hasPrettyPrintLink: true },
+    "The XML file has the pretty print shadowRoot"
+  );
+
+  await contentPage.close();
+  await extension.unload();
+});