import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

devtools/client/responsive.html/test/browser/browser_screenshot_button.js

@@ -0,0 +1,59 @@
+/* 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");
+
+function* waitUntilScreenshot() {
+  return new Promise(Task.async(function* (resolve) {
+    let { Downloads } = require("resource://gre/modules/Downloads.jsm");
+    let list = yield Downloads.getList(Downloads.ALL);
+
+    let view = {
+      onDownloadAdded: download => {
+        download.whenSucceeded().then(() => {
+          resolve(download.target.path);
+          list.removeView(view);
+        });
+      }
+    };
+
+    yield list.addView(view);
+  }));
+}
+
+addRDMTask(TEST_URL, function* ({ ui: {toolWindow} }) {
+  let { store, document } = toolWindow;
+
+  // Wait until the viewport has been added
+  yield waitUntilState(store, state => state.viewports.length == 1);
+
+  info("Click the screenshot button");
+  let screenshotButton = document.getElementById("global-screenshot-button");
+  screenshotButton.click();
+
+  let whenScreenshotSucceeded = waitUntilScreenshot();
+
+  let filePath = yield whenScreenshotSucceeded;
+  let image = new Image();
+  image.src = OS.Path.toFileURI(filePath);
+
+  yield once(image, "load");
+
+  // We have only one viewport at the moment
+  let viewport = store.getState().viewports[0];
+  let 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");
+
+  yield OS.File.remove(filePath);
+});