Bug 1768475 - [devtools] WalkerActor watchRootNode should not check isDocumentReady r=devtools-reviewers,nchevobbe

If the walker actor was initialized, we assume the document is ready enough and a root node can be returned if available. A new test was added for a slow loading document. Differential Revision: https://phabricator.services.mozilla.com/D146464
2022-05-17 06:04:47 +00:00 · 2022-05-17 06:04:47 +00:00 · e4e4e73bb9
--- a/devtools/client/inspector/test/browser_inspector_inspect_loading_document.js
+++ b/devtools/client/inspector/test/browser_inspector_inspect_loading_document.js
@ -26,7 +26,7 @@ const TEST_URL =
  </html>
 `);

-add_task(async function() {
+add_task(async function testSlowLoadingFrame() {
  const loadingTab = BrowserTestUtils.addTab(gBrowser, TEST_URL);
  gBrowser.selectedTab = loadingTab;

@ -67,3 +67,96 @@ add_task(async function() {
    inspector
  );
 });
+
+const DOCUMENT_DELAY = 5000;
+
+add_task(async function testSlowLoadingDocument() {
+  info("Create a test server serving a slow document");
+  const httpServer = createTestHTTPServer();
+  httpServer.registerContentType("html", "text/html");
+
+  httpServer.registerPathHandler(`/`, async function(request, response) {
+    response.processAsync();
+    response.setStatusLine(request.httpVersion, 200, "OK");
+
+    // Split the page content in 2 parts:
+    // - opening body tag and the "#start" div will be returned immediately
+    // - "#end" div and closing body tag are returned after a delay.
+    const page_start = "<body><div id='start'>start</div>";
+    const page_end = "<div id='end'>end</div></body>";
+    const page = page_start + page_end;
+
+    response.setHeader("Content-Type", "text/html; charset=utf-8", false);
+    response.setHeader("Content-Length", page.length + "", false);
+    response.write(page_start);
+
+    await wait(DOCUMENT_DELAY);
+    response.write(page_end);
+    response.finish();
+  });
+
+  const port = httpServer.identity.primaryPort;
+  const TEST_URL_2 = `http://localhost:${port}/`;
+
+  // Same as in the other task, we cannot wait for the full load.
+  info("Open a new tab on TEST_URL_2 and select it");
+  const loadingTab = BrowserTestUtils.addTab(gBrowser, TEST_URL_2);
+  gBrowser.selectedTab = loadingTab;
+
+  info("Wait for the #start div to be available in the document");
+  await TestUtils.waitForCondition(async () => {
+    try {
+      return await ContentTask.spawn(gBrowser.selectedBrowser, {}, () =>
+        content.document.getElementById("start")
+      );
+    } catch (e) {
+      return false;
+    }
+  });
+
+  const { inspector } = await openInspector();
+
+  info("Check that the inspector is not blank and only shows the #start div");
+  await assertMarkupViewAsTree(
+    `
+    body
+      div id="start"`,
+    "body",
+    inspector
+  );
+
+  // Navigate to about:blank to clean the state.
+  await navigateTo("about:blank");
+
+  await navigateTo(TEST_URL_2, { waitForLoad: false });
+  info("Wait for the #start div to be available as a markupview container");
+  await TestUtils.waitForCondition(async () => {
+    const nodeFront = await getNodeFront("#start", inspector);
+    return nodeFront && getContainerForNodeFront(nodeFront, inspector);
+  });
+
+  info("Check that the inspector is not blank and only shows the #start div");
+  await assertMarkupViewAsTree(
+    `
+    body
+      div id="start"`,
+    "body",
+    inspector
+  );
+
+  info("Wait for the #end div to be available as a markupview container");
+  await TestUtils.waitForCondition(async () => {
+    const nodeFront = await getNodeFront("#end", inspector);
+    return nodeFront && getContainerForNodeFront(nodeFront, inspector);
+  });
+
+  info("Check that the inspector will ultimately show the #end div");
+  await assertMarkupViewAsTree(
+    `
+    body
+      div id="start"
+      div id="end"`,
+    "body",
+    inspector
+  );
+});
--- a/devtools/server/actors/inspector/walker.js
+++ b/devtools/server/actors/inspector/walker.js
@ -43,7 +43,6 @@ loader.lazyRequireGetter(
  [
    "allAnonymousContentTreeWalkerFilter",
    "findGridParentContainerForNode",
-    "isDocumentReady",
    "isNodeDead",
    "noAnonymousContentTreeWalkerFilter",
    "nodeDocument",
@ -291,7 +290,7 @@ var WalkerActor = protocol.ActorClassWithSpec(walkerSpec, {
  },

  watchRootNode() {
-    if (this.rootNode && isDocumentReady(this.rootDoc)) {
+    if (this.rootNode) {
      this.emit("root-available", this.rootNode);
    }
  },