1 files changed, 91 insertions, 0 deletions
diff --git a/devtools/client/inspector/markup/test/browser_markup_pagesize_01.js b/devtools/client/inspector/markup/test/browser_markup_pagesize_01.js
new file mode 100644
index 0000000000..1700c9a433
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+++ b/devtools/client/inspector/markup/test/browser_markup_pagesize_01.js
@@ -0,0 +1,91 @@
+/* Any copyright is dedicated to the Public Domain.
+ http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Tests that the markup view loads only as many nodes as specified by the
+// devtools.markup.pagesize preference.
+
+Services.prefs.setIntPref("devtools.markup.pagesize", 5);
+
+const TEST_URL = URL_ROOT + "doc_markup_pagesize_01.html";
+const TEST_DATA = [
+  {
+    desc: "Select the last item",
+    selector: "#z",
+    expected: "*more*vwxyz",
+  },
+  {
+    desc: "Select the first item",
+    selector: "#a",
+    expected: "abcde*more*",
+  },
+  {
+    desc: "Select the last item",
+    selector: "#z",
+    expected: "*more*vwxyz",
+  },
+  {
+    desc: "Select an already-visible item",
+    selector: "#v",
+    // Because "v" was already visible, we shouldn't have loaded
+    // a different page.
+    expected: "*more*vwxyz",
+  },
+  {
+    desc: "Verify childrenDirty reloads the page",
+    selector: "#w",
+    forceReload: true,
+    // But now that we don't already have a loaded page, selecting
+    // w should center around w.
+    expected: "*more*uvwxy*more*",
+  },
+];
+
+add_task(async function () {
+  const { inspector } = await openInspectorForURL(TEST_URL);
+
+  info("Start iterating through the test data");
+  for (const step of TEST_DATA) {
+    info("Start test: " + step.desc);
+
+    if (step.forceReload) {
+      await forceReload(inspector);
+    }
+    info("Selecting the node that corresponds to " + step.selector);
+    await selectNode(step.selector, inspector);
+
+    info("Checking that the right nodes are shwon");
+    await assertChildren(step.expected, inspector);
+  }
+
+  info("Checking that clicking the more button loads everything");
+  await clickShowMoreNodes(inspector);
+  await inspector.markup._waitForChildren();
+  await assertChildren("abcdefghijklmnopqrstuvwxyz", inspector);
+});
+
+async function assertChildren(expected, inspector) {
+  const container = await getContainerForSelector("body", inspector);
+  let found = "";
+  for (const child of container.children.children) {
+    if (child.classList.contains("more-nodes")) {
+      found += "*more*";
+    } else {
+      found += child.container.node.getAttribute("id");
+    }
+  }
+  is(found, expected, "Got the expected children.");
+}
+
+async function forceReload(inspector) {
+  const container = await getContainerForSelector("body", inspector);
+  container.childrenDirty = true;
+}
+
+async function clickShowMoreNodes(inspector) {
+  const container = await getContainerForSelector("body", inspector);
+  const button = container.elt.querySelector("button");
+  const win = button.ownerDocument.defaultView;
+  EventUtils.sendMouseEvent({ type: "click" }, button, win);
+}