1 files changed, 86 insertions, 0 deletions
diff --git a/devtools/client/responsive/test/browser/browser_viewport_resizing_scrollbar.js b/devtools/client/responsive/test/browser/browser_viewport_resizing_scrollbar.js
new file mode 100644
index 0000000000..ed4de1711e
--- /dev/null
+++ b/devtools/client/responsive/test/browser/browser_viewport_resizing_scrollbar.js
@@ -0,0 +1,86 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test scrollbar appearance after viewport resizing, with and without
+// meta viewport support.
+
+Services.scriptloader.loadSubScript(
+  "chrome://mochikit/content/tests/SimpleTest/WindowSnapshot.js",
+  this
+);
+
+// The quest for a TEST_ROOT: we have to choose a way of addressing the RDM document
+// such that two things can happen:
+// 1) addRDMTask can load it.
+// 2) WindowSnapshot can take a picture of it.
+
+// The WindowSnapshot does not work cross-origin. We can't use a data URI, because those
+// are considered cross-origin.
+
+// let TEST_ROOT = "";
+
+// We can't use a relative URL, because addRDMTask can't load local files.
+// TEST_ROOT = "";
+
+// We can't use a mochi.test URL, because it's cross-origin.
+// TEST_ROOT =
+//   "http://mochi.test:8888/browser/devtools/client/responsive/test/browser/";
+
+// We can't use a chrome URL, because it triggers an assertion: RDM only available for
+// remote tabs.
+// TEST_ROOT =
+//   "chrome://mochitests/content/browser/devtools/client/responsive/test/browser/";
+
+// So if we had an effective TEST_ROOT, we'd use it here and run our test. But we don't.
+// The proposed "file_meta_1000_div.html" would just contain the html specified below as
+// a data URI.
+// const TEST_URL = TEST_ROOT + "file_meta_1000_div.html";
+
+// Instead we're going to mess with a security preference to allow a data URI to be
+// treated as same-origin. This doesn't work either for reasons that I don't understand.
+
+const TEST_URL =
+  "data:text/html;charset=utf-8," +
+  "<head>" +
+  '<meta name="viewport" content="width=device-width, initial-scale=1"/>' +
+  "</head>" +
+  '<body><div style="background:orange; width:1000px; height:1000px"></div></body>';
+
+addRDMTask(TEST_URL, async function ({ ui, manager }) {
+  // Turn on the prefs that force overlay scrollbars to always be visible.
+  await SpecialPowers.pushPrefEnv({
+    set: [["layout.testing.overlay-scrollbars.always-visible", true]],
+  });
+
+  info("--- Starting viewport test output ---");
+
+  const browser = ui.getViewportBrowser();
+
+  const expected = [false, true];
+  for (const e of expected) {
+    const message = "Meta Viewport " + (e ? "ON" : "OFF");
+
+    // Ensure meta viewport is set.
+    info(message + " setting meta viewport support.");
+    await setTouchAndMetaViewportSupport(ui, e.metaSupport);
+
+    // Get to the initial size and snapshot the window.
+    await setViewportSizeAndAwaitReflow(ui, manager, 300, 600);
+    const initialSnapshot = await snapshotWindow(browser);
+
+    // Move to the rotated size.
+    await setViewportSizeAndAwaitReflow(ui, manager, 600, 300);
+
+    // Reload the window.
+    await reloadBrowser();
+
+    // Go back to the initial size and take another snapshot.
+    await setViewportSizeAndAwaitReflow(ui, manager, 300, 600);
+    const finalSnapshot = await snapshotWindow(browser);
+
+    const result = compareSnapshots(initialSnapshot, finalSnapshot, true);
+    is(result[2], result[1], "Window snapshots should match.");
+  }
+});