1 files changed, 63 insertions, 0 deletions
diff --git a/devtools/client/responsive/test/browser/browser_screenshot_button.js b/devtools/client/responsive/test/browser/browser_screenshot_button.js
new file mode 100644
index 0000000000..4dcb429087
--- /dev/null
+++ b/devtools/client/responsive/test/browser/browser_screenshot_button.js
@@ -0,0 +1,63 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test global exit button
+
+const TEST_URL = "data:text/html;charset=utf-8,";
+
+const { OS } = require("resource://gre/modules/osfile.jsm");
+
+async function waitUntilScreenshot() {
+  const { Downloads } = require("resource://gre/modules/Downloads.jsm");
+  const list = await Downloads.getList(Downloads.ALL);
+
+  return new Promise(function(resolve) {
+    const view = {
+      onDownloadAdded: download => {
+        download.whenSucceeded().then(() => {
+          resolve(download.target.path);
+          list.removeView(view);
+        });
+      },
+    };
+
+    list.addView(view);
+  });
+}
+
+addRDMTask(TEST_URL, async function({ ui }) {
+  const { toolWindow } = ui;
+  const { store, document } = toolWindow;
+
+  info("Click the screenshot button");
+  const screenshotButton = document.getElementById("screenshot-button");
+  screenshotButton.click();
+
+  const whenScreenshotSucceeded = waitUntilScreenshot();
+
+  const filePath = await whenScreenshotSucceeded;
+  const image = new Image();
+  image.src = OS.Path.toFileURI(filePath);
+
+  await once(image, "load");
+
+  // We have only one viewport at the moment
+  const viewport = store.getState().viewports[0];
+  const ratio = window.devicePixelRatio;
+
+  is(
+    image.width,
+    viewport.width * ratio,
+    "screenshot width has the expected width"
+  );
+
+  is(
+    image.height,
+    viewport.height * ratio,
+    "screenshot width has the expected height"
+  );
+
+  await OS.File.remove(filePath);
+});