1 files changed, 59 insertions, 0 deletions
diff --git a/devtools/client/responsive/test/browser/browser_screenshot_button_warning.js b/devtools/client/responsive/test/browser/browser_screenshot_button_warning.js
new file mode 100644
index 0000000000..f7940b3cbf
--- /dev/null
+++ b/devtools/client/responsive/test/browser/browser_screenshot_button_warning.js
@@ -0,0 +1,59 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test that warning messages emitted when taking a screenshot are displayed in the UI.
+
+const TEST_URL = `http://example.net/document-builder.sjs?html=
+  <style>
+    body {
+      margin: 0;
+      height: 10001px;
+    }
+  </style>Hello world`;
+
+addRDMTask(
+  TEST_URL,
+  async function ({ ui, browser, manager }) {
+    const { toolWindow } = ui;
+    const { document } = toolWindow;
+
+    info(
+      "Set a big viewport and high dpr so the screenshot dpr gets downsized"
+    );
+    // The viewport can't be bigger than 9999×9999
+    await setViewportSize(ui, manager, 9999, 9999);
+    const dpr = 3;
+    await selectDevicePixelRatio(ui, dpr);
+    await waitForDevicePixelRatio(ui, dpr);
+
+    info("Click the screenshot button");
+    const onScreenshotDownloaded = waitUntilScreenshot();
+    const screenshotButton = document.getElementById("screenshot-button");
+    screenshotButton.click();
+
+    const filePath = await onScreenshotDownloaded;
+    ok(filePath, "The screenshot was taken");
+
+    info(
+      "Check that a warning message was displayed to indicate the dpr was changed"
+    );
+
+    const box = gBrowser.getNotificationBox(browser);
+    await waitUntil(() => box.currentNotification);
+
+    const notificationEl = box.currentNotification;
+    ok(notificationEl, "Notification should be visible");
+    is(
+      notificationEl.messageText.textContent.trim(),
+      "The device pixel ratio was reduced to 1 as the resulting image was too large",
+      "The expected warning was displayed"
+    );
+
+    //Remove the downloaded screenshot file
+    await IOUtils.remove(filePath);
+    await resetDownloads();
+  },
+  { waitForDeviceList: true }
+);