1 files changed, 44 insertions, 0 deletions
diff --git a/gfx/layers/apz/test/mochitest/browser_test_reset_scaling_zoom.js b/gfx/layers/apz/test/mochitest/browser_test_reset_scaling_zoom.js
new file mode 100644
index 0000000000..168d358fcb
--- /dev/null
+++ b/gfx/layers/apz/test/mochitest/browser_test_reset_scaling_zoom.js
@@ -0,0 +1,44 @@
+add_task(async function setup_pref() {
+  let isWindows = navigator.platform.indexOf("Win") == 0;
+  await SpecialPowers.pushPrefEnv({
+    set: [["apz.test.fails_with_native_injection", isWindows]],
+  });
+});
+
+add_task(async function test_main() {
+  function httpURL(filename) {
+    let chromeURL = getRootDirectory(gTestPath) + filename;
+    return chromeURL.replace(
+      "chrome://mochitests/content/",
+      "http://mochi.test:8888/"
+    );
+  }
+
+  const pageUrl = httpURL("helper_test_reset_scaling_zoom.html");
+
+  await BrowserTestUtils.withNewTab(pageUrl, async function (browser) {
+    let getResolution = function () {
+      return content.window.SpecialPowers.getDOMWindowUtils(
+        content.window
+      ).getResolution();
+    };
+
+    let doZoomIn = async function () {
+      await content.window.wrappedJSObject.doZoomIn();
+    };
+
+    let resolution = await ContentTask.spawn(browser, null, getResolution);
+    is(resolution, 1.0, "Initial page resolution should be 1.0");
+
+    await ContentTask.spawn(browser, null, doZoomIn);
+    resolution = await ContentTask.spawn(browser, null, getResolution);
+    isnot(resolution, 1.0, "Expected resolution to be bigger than 1.0");
+
+    document.getElementById("cmd_fullZoomReset").doCommand();
+    // Spin the event loop once just to make sure the message gets through
+    await new Promise(resolve => setTimeout(resolve, 0));
+
+    resolution = await ContentTask.spawn(browser, null, getResolution);
+    is(resolution, 1.0, "Expected resolution to be reset to 1.0");
+  });
+});