Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 907 insertions, 0 deletions

diff --git a/remote/marionette/reftest.sys.mjs b/remote/marionette/reftest.sys.mjs
new file mode 100644
index 0000000000..635f2196ef
--- /dev/null
+++ b/remote/marionette/reftest.sys.mjs
@@ -0,0 +1,907 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  clearTimeout: "resource://gre/modules/Timer.sys.mjs",
+  E10SUtils: "resource://gre/modules/E10SUtils.sys.mjs",
+  setTimeout: "resource://gre/modules/Timer.sys.mjs",
+
+  AppInfo: "chrome://remote/content/shared/AppInfo.sys.mjs",
+  assert: "chrome://remote/content/shared/webdriver/Assert.sys.mjs",
+  capture: "chrome://remote/content/shared/Capture.sys.mjs",
+  Log: "chrome://remote/content/shared/Log.sys.mjs",
+  navigate: "chrome://remote/content/marionette/navigate.sys.mjs",
+  print: "chrome://remote/content/shared/PDF.sys.mjs",
+  windowManager: "chrome://remote/content/shared/WindowManager.sys.mjs",
+});
+
+XPCOMUtils.defineLazyGetter(lazy, "logger", () =>
+  lazy.Log.get(lazy.Log.TYPES.MARIONETTE)
+);
+
+const XHTML_NS = "http://www.w3.org/1999/xhtml";
+const XUL_NS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
+
+const SCREENSHOT_MODE = {
+  unexpected: 0,
+  fail: 1,
+  always: 2,
+};
+
+const STATUS = {
+  PASS: "PASS",
+  FAIL: "FAIL",
+  ERROR: "ERROR",
+  TIMEOUT: "TIMEOUT",
+};
+
+const DEFAULT_REFTEST_WIDTH = 600;
+const DEFAULT_REFTEST_HEIGHT = 600;
+
+// reftest-print page dimensions in cm
+const CM_PER_INCH = 2.54;
+const DEFAULT_PAGE_WIDTH = 5 * CM_PER_INCH;
+const DEFAULT_PAGE_HEIGHT = 3 * CM_PER_INCH;
+const DEFAULT_PAGE_MARGIN = 0.5 * CM_PER_INCH;
+
+// CSS 96 pixels per inch, compared to pdf.js default 72 pixels per inch
+const DEFAULT_PDF_RESOLUTION = 96 / 72;
+
+/**
+ * Implements an fast runner for web-platform-tests format reftests
+ * c.f. http://web-platform-tests.org/writing-tests/reftests.html.
+ *
+ * @namespace
+ */
+export const reftest = {};
+
+/**
+ * @memberof reftest
+ * @class Runner
+ */
+reftest.Runner = class {
+  constructor(driver) {
+    this.driver = driver;
+    this.canvasCache = new DefaultMap(undefined, () => new Map([[null, []]]));
+    this.isPrint = null;
+    this.windowUtils = null;
+    this.lastURL = null;
+    this.useRemoteTabs = lazy.AppInfo.browserTabsRemoteAutostart;
+    this.useRemoteSubframes = lazy.AppInfo.fissionAutostart;
+  }
+
+  /**
+   * Setup the required environment for running reftests.
+   *
+   * This will open a non-browser window in which the tests will
+   * be loaded, and set up various caches for the reftest run.
+   *
+   * @param {Object<number>} urlCount
+   *     Object holding a map of URL: number of times the URL
+   *     will be opened during the reftest run, where that's
+   *     greater than 1.
+   * @param {string} screenshotMode
+   *     String enum representing when screenshots should be taken
+   */
+  setup(urlCount, screenshotMode, isPrint = false) {
+    this.isPrint = isPrint;
+
+    lazy.assert.open(this.driver.getBrowsingContext({ top: true }));
+    this.parentWindow = this.driver.getCurrentWindow();
+
+    this.screenshotMode =
+      SCREENSHOT_MODE[screenshotMode] || SCREENSHOT_MODE.unexpected;
+
+    this.urlCount = Object.keys(urlCount || {}).reduce(
+      (map, key) => map.set(key, urlCount[key]),
+      new Map()
+    );
+
+    if (isPrint) {
+      this.loadPdfJs();
+    }
+
+    ChromeUtils.registerWindowActor("MarionetteReftest", {
+      kind: "JSWindowActor",
+      parent: {
+        esModuleURI:
+          "chrome://remote/content/marionette/actors/MarionetteReftestParent.sys.mjs",
+      },
+      child: {
+        esModuleURI:
+          "chrome://remote/content/marionette/actors/MarionetteReftestChild.sys.mjs",
+        events: {
+          load: { mozSystemGroup: true, capture: true },
+        },
+      },
+      allFrames: true,
+    });
+  }
+
+  /**
+   * Cleanup the environment once the reftest is finished.
+   */
+  teardown() {
+    // Abort the current test if any.
+    this.abort();
+
+    // Unregister the JSWindowActors.
+    ChromeUtils.unregisterWindowActor("MarionetteReftest");
+  }
+
+  async ensureWindow(timeout, width, height) {
+    lazy.logger.debug(`ensuring we have a window ${width}x${height}`);
+
+    if (this.reftestWin && !this.reftestWin.closed) {
+      let browserRect = this.reftestWin.gBrowser.getBoundingClientRect();
+      if (browserRect.width === width && browserRect.height === height) {
+        return this.reftestWin;
+      }
+      lazy.logger.debug(`current: ${browserRect.width}x${browserRect.height}`);
+    }
+
+    let reftestWin;
+    if (lazy.AppInfo.isAndroid) {
+      lazy.logger.debug("Using current window");
+      reftestWin = this.parentWindow;
+      await lazy.navigate.waitForNavigationCompleted(this.driver, () => {
+        const browsingContext = this.driver.getBrowsingContext();
+        lazy.navigate.navigateTo(browsingContext, "about:blank");
+      });
+    } else {
+      lazy.logger.debug("Using separate window");
+      if (this.reftestWin && !this.reftestWin.closed) {
+        this.reftestWin.close();
+      }
+      reftestWin = await this.openWindow(width, height);
+    }
+
+    this.setupWindow(reftestWin, width, height);
+    this.windowUtils = reftestWin.windowUtils;
+    this.reftestWin = reftestWin;
+
+    let windowHandle = lazy.windowManager.getWindowProperties(reftestWin);
+    await this.driver.setWindowHandle(windowHandle, true);
+
+    const url = await this.driver._getCurrentURL();
+    this.lastURL = url.href;
+    lazy.logger.debug(`loaded initial URL: ${this.lastURL}`);
+
+    let browserRect = reftestWin.gBrowser.getBoundingClientRect();
+    lazy.logger.debug(`new: ${browserRect.width}x${browserRect.height}`);
+
+    return reftestWin;
+  }
+
+  async openWindow(width, height) {
+    lazy.assert.positiveInteger(width);
+    lazy.assert.positiveInteger(height);
+
+    let reftestWin = this.parentWindow.open(
+      "chrome://remote/content/marionette/reftest.xhtml",
+      "reftest",
+      `chrome,height=${height},width=${width}`
+    );
+
+    await new Promise(resolve => {
+      reftestWin.addEventListener("load", resolve, { once: true });
+    });
+    return reftestWin;
+  }
+
+  setupWindow(reftestWin, width, height) {
+    let browser;
+    if (lazy.AppInfo.isAndroid) {
+      browser = reftestWin.document.getElementsByTagName("browser")[0];
+      browser.setAttribute("remote", "false");
+    } else {
+      browser = reftestWin.document.createElementNS(XUL_NS, "xul:browser");
+      browser.permanentKey = {};
+      browser.setAttribute("id", "browser");
+      browser.setAttribute("type", "content");
+      browser.setAttribute("primary", "true");
+      browser.setAttribute("remote", this.useRemoteTabs ? "true" : "false");
+    }
+    // Make sure the browser element is exactly the right size, no matter
+    // what size our window is
+    const windowStyle = `
+      padding: 0px;
+      margin: 0px;
+      border:none;
+      min-width: ${width}px; min-height: ${height}px;
+      max-width: ${width}px; max-height: ${height}px;
+      color-scheme: env(-moz-content-preferred-color-scheme);
+    `;
+    browser.setAttribute("style", windowStyle);
+
+    if (!lazy.AppInfo.isAndroid) {
+      let doc = reftestWin.document.documentElement;
+      while (doc.firstChild) {
+        doc.firstChild.remove();
+      }
+      doc.appendChild(browser);
+    }
+    if (reftestWin.BrowserApp) {
+      reftestWin.BrowserApp = browser;
+    }
+    reftestWin.gBrowser = browser;
+    return reftestWin;
+  }
+
+  async abort() {
+    if (this.reftestWin && this.reftestWin != this.parentWindow) {
+      await this.driver.closeChromeWindow();
+      let parentHandle = lazy.windowManager.getWindowProperties(
+        this.parentWindow
+      );
+      await this.driver.setWindowHandle(parentHandle);
+    }
+    this.reftestWin = null;
+  }
+
+  /**
+   * Run a specific reftest.
+   *
+   * The assumed semantics are those of web-platform-tests where
+   * references form a tree and each test must meet all the conditions
+   * to reach one leaf node of the tree in order for the overall test
+   * to pass.
+   *
+   * @param {string} testUrl
+   *     URL of the test itself.
+   * @param {Array.<Array>} references
+   *     Array representing a tree of references to try.
+   *
+   *     Each item in the array represents a single reference node and
+   *     has the form <code>[referenceUrl, references, relation]</code>,
+   *     where <var>referenceUrl</var> is a string to the URL, relation
+   *     is either <code>==</code> or <code>!=</code> depending on the
+   *     type of reftest, and references is another array containing
+   *     items of the same form, representing further comparisons treated
+   *     as AND with the current item. Sibling entries are treated as OR.
+   *
+   *     For example with testUrl of T:
+   *
+   *     <pre><code>
+   *       references = [[A, [[B, [], ==]], ==]]
+   *       Must have T == A AND A == B to pass
+   *
+   *       references = [[A, [], ==], [B, [], !=]
+   *       Must have T == A OR T != B
+   *
+   *       references = [[A, [[B, [], ==], [C, [], ==]], ==], [D, [], ]]
+   *       Must have (T == A AND A == B) OR (T == A AND A == C) OR (T == D)
+   *     </code></pre>
+   *
+   * @param {string} expected
+   *     Expected test outcome (e.g. <tt>PASS</tt>, <tt>FAIL</tt>).
+   * @param {number} timeout
+   *     Test timeout in milliseconds.
+   *
+   * @returns {object}
+   *     Result object with fields status, message and extra.
+   */
+  async run(
+    testUrl,
+    references,
+    expected,
+    timeout,
+    pageRanges = {},
+    width = DEFAULT_REFTEST_WIDTH,
+    height = DEFAULT_REFTEST_HEIGHT
+  ) {
+    let timerId;
+
+    let timeoutPromise = new Promise(resolve => {
+      timerId = lazy.setTimeout(() => {
+        resolve({ status: STATUS.TIMEOUT, message: null, extra: {} });
+      }, timeout);
+    });
+
+    let testRunner = (async () => {
+      let result;
+      try {
+        result = await this.runTest(
+          testUrl,
+          references,
+          expected,
+          timeout,
+          pageRanges,
+          width,
+          height
+        );
+      } catch (e) {
+        result = {
+          status: STATUS.ERROR,
+          message: String(e),
+          stack: e.stack,
+          extra: {},
+        };
+      }
+      return result;
+    })();
+
+    let result = await Promise.race([testRunner, timeoutPromise]);
+    lazy.clearTimeout(timerId);
+    if (result.status === STATUS.TIMEOUT) {
+      await this.abort();
+    }
+
+    return result;
+  }
+
+  async runTest(
+    testUrl,
+    references,
+    expected,
+    timeout,
+    pageRanges,
+    width,
+    height
+  ) {
+    let win = await this.ensureWindow(timeout, width, height);
+
+    function toBase64(screenshot) {
+      let dataURL = screenshot.canvas.toDataURL();
+      return dataURL.split(",")[1];
+    }
+
+    let result = {
+      status: STATUS.FAIL,
+      message: "",
+      stack: null,
+      extra: {},
+    };
+
+    let screenshotData = [];
+
+    let stack = [];
+    for (let i = references.length - 1; i >= 0; i--) {
+      let item = references[i];
+      stack.push([testUrl, ...item]);
+    }
+
+    let done = false;
+
+    while (stack.length && !done) {
+      let [lhsUrl, rhsUrl, references, relation, extras = {}] = stack.pop();
+      result.message += `Testing ${lhsUrl} ${relation} ${rhsUrl}\n`;
+
+      let comparison;
+      try {
+        comparison = await this.compareUrls(
+          win,
+          lhsUrl,
+          rhsUrl,
+          relation,
+          timeout,
+          pageRanges,
+          extras
+        );
+      } catch (e) {
+        comparison = {
+          lhs: null,
+          rhs: null,
+          passed: false,
+          error: e,
+          msg: null,
+        };
+      }
+      if (comparison.msg) {
+        result.message += `${comparison.msg}\n`;
+      }
+      if (comparison.error !== null) {
+        result.status = STATUS.ERROR;
+        result.message += String(comparison.error);
+        result.stack = comparison.error.stack;
+      }
+
+      function recordScreenshot() {
+        let encodedLHS = comparison.lhs ? toBase64(comparison.lhs) : "";
+        let encodedRHS = comparison.rhs ? toBase64(comparison.rhs) : "";
+        screenshotData.push([
+          { url: lhsUrl, screenshot: encodedLHS },
+          relation,
+          { url: rhsUrl, screenshot: encodedRHS },
+        ]);
+      }
+
+      if (this.screenshotMode === SCREENSHOT_MODE.always) {
+        recordScreenshot();
+      }
+
+      if (comparison.passed) {
+        if (references.length) {
+          for (let i = references.length - 1; i >= 0; i--) {
+            let item = references[i];
+            stack.push([rhsUrl, ...item]);
+          }
+        } else {
+          // Reached a leaf node so all of one reference chain passed
+          result.status = STATUS.PASS;
+          if (
+            this.screenshotMode <= SCREENSHOT_MODE.fail &&
+            expected != result.status
+          ) {
+            recordScreenshot();
+          }
+          done = true;
+        }
+      } else if (!stack.length || result.status == STATUS.ERROR) {
+        // If we don't have any alternatives to try then this will be
+        // the last iteration, so save the failing screenshots if required.
+        let isFail = this.screenshotMode === SCREENSHOT_MODE.fail;
+        let isUnexpected = this.screenshotMode === SCREENSHOT_MODE.unexpected;
+        if (isFail || (isUnexpected && expected != result.status)) {
+          recordScreenshot();
+        }
+      }
+
+      // Return any reusable canvases to the pool
+      let cacheKey = width + "x" + height;
+      let canvasPool = this.canvasCache.get(cacheKey).get(null);
+      [comparison.lhs, comparison.rhs].map(screenshot => {
+        if (screenshot !== null && screenshot.reuseCanvas) {
+          canvasPool.push(screenshot.canvas);
+        }
+      });
+      lazy.logger.debug(
+        `Canvas pool (${cacheKey}) is of length ${canvasPool.length}`
+      );
+    }
+
+    if (screenshotData.length) {
+      // For now the tbpl formatter only accepts one screenshot, so just
+      // return the last one we took.
+      let lastScreenshot = screenshotData[screenshotData.length - 1];
+      // eslint-disable-next-line camelcase
+      result.extra.reftest_screenshots = lastScreenshot;
+    }
+
+    return result;
+  }
+
+  async compareUrls(
+    win,
+    lhsUrl,
+    rhsUrl,
+    relation,
+    timeout,
+    pageRanges,
+    extras
+  ) {
+    lazy.logger.info(`Testing ${lhsUrl} ${relation} ${rhsUrl}`);
+
+    if (relation !== "==" && relation != "!=") {
+      throw new error.InvalidArgumentError(
+        "Reftest operator should be '==' or '!='"
+      );
+    }
+
+    let lhsIter, lhsCount, rhsIter, rhsCount;
+    if (!this.isPrint) {
+      // Take the reference screenshot first so that if we pause
+      // we see the test rendering
+      rhsIter = [await this.screenshot(win, rhsUrl, timeout)].values();
+      lhsIter = [await this.screenshot(win, lhsUrl, timeout)].values();
+      lhsCount = rhsCount = 1;
+    } else {
+      [rhsIter, rhsCount] = await this.screenshotPaginated(
+        win,
+        rhsUrl,
+        timeout,
+        pageRanges
+      );
+      [lhsIter, lhsCount] = await this.screenshotPaginated(
+        win,
+        lhsUrl,
+        timeout,
+        pageRanges
+      );
+    }
+
+    let passed = null;
+    let error = null;
+    let pixelsDifferent = null;
+    let maxDifferences = {};
+    let msg = null;
+
+    if (lhsCount != rhsCount) {
+      passed = relation == "!=";
+      if (!passed) {
+        msg = `Got different numbers of pages; test has ${lhsCount}, ref has ${rhsCount}`;
+      }
+    }
+
+    let lhs = null;
+    let rhs = null;
+    lazy.logger.debug(`Comparing ${lhsCount} pages`);
+    if (passed === null) {
+      for (let i = 0; i < lhsCount; i++) {
+        lhs = (await lhsIter.next()).value;
+        rhs = (await rhsIter.next()).value;
+        lazy.logger.debug(
+          `lhs canvas size ${lhs.canvas.width}x${lhs.canvas.height}`
+        );
+        lazy.logger.debug(
+          `rhs canvas size ${rhs.canvas.width}x${rhs.canvas.height}`
+        );
+        try {
+          pixelsDifferent = this.windowUtils.compareCanvases(
+            lhs.canvas,
+            rhs.canvas,
+            maxDifferences
+          );
+        } catch (e) {
+          error = e;
+          passed = false;
+          break;
+        }
+
+        let areEqual = this.isAcceptableDifference(
+          maxDifferences.value,
+          pixelsDifferent,
+          extras.fuzzy
+        );
+        lazy.logger.debug(
+          `Page ${i + 1} maxDifferences: ${maxDifferences.value} ` +
+            `pixelsDifferent: ${pixelsDifferent}`
+        );
+        lazy.logger.debug(
+          `Page ${i + 1} ${areEqual ? "compare equal" : "compare unequal"}`
+        );
+        if (!areEqual) {
+          if (relation == "==") {
+            passed = false;
+            msg =
+              `Found ${pixelsDifferent} pixels different, ` +
+              `maximum difference per channel ${maxDifferences.value}`;
+            if (this.isPrint) {
+              msg += ` on page ${i + 1}`;
+            }
+          } else {
+            passed = true;
+          }
+          break;
+        }
+      }
+    }
+
+    // If passed isn't set we got to the end without finding differences
+    if (passed === null) {
+      if (relation == "==") {
+        passed = true;
+      } else {
+        msg = `mismatch reftest has no differences`;
+        passed = false;
+      }
+    }
+    return { lhs, rhs, passed, error, msg };
+  }
+
+  isAcceptableDifference(maxDifference, pixelsDifferent, allowed) {
+    if (!allowed) {
+      lazy.logger.info(`No differences allowed`);
+      return pixelsDifferent === 0;
+    }
+    let [allowedDiff, allowedPixels] = allowed;
+    lazy.logger.info(
+      `Allowed ${allowedPixels.join("-")} pixels different, ` +
+        `maximum difference per channel ${allowedDiff.join("-")}`
+    );
+    return (
+      (pixelsDifferent === 0 && allowedPixels[0] == 0) ||
+      (maxDifference === 0 && allowedDiff[0] == 0) ||
+      (maxDifference >= allowedDiff[0] &&
+        maxDifference <= allowedDiff[1] &&
+        (pixelsDifferent >= allowedPixels[0] ||
+          pixelsDifferent <= allowedPixels[1]))
+    );
+  }
+
+  ensureFocus(win) {
+    const focusManager = Services.focus;
+    if (focusManager.activeWindow != win) {
+      win.focus();
+    }
+    this.driver.curBrowser.contentBrowser.focus();
+  }
+
+  updateBrowserRemotenessByURL(browser, url) {
+    // We don't use remote tabs on Android.
+    if (lazy.AppInfo.isAndroid) {
+      return;
+    }
+    let oa = lazy.E10SUtils.predictOriginAttributes({ browser });
+    let remoteType = lazy.E10SUtils.getRemoteTypeForURI(
+      url,
+      this.useRemoteTabs,
+      this.useRemoteSubframes,
+      lazy.E10SUtils.DEFAULT_REMOTE_TYPE,
+      null,
+      oa
+    );
+
+    // Only re-construct the browser if its remote type needs to change.
+    if (browser.remoteType !== remoteType) {
+      if (remoteType === lazy.E10SUtils.NOT_REMOTE) {
+        browser.removeAttribute("remote");
+        browser.removeAttribute("remoteType");
+      } else {
+        browser.setAttribute("remote", "true");
+        browser.setAttribute("remoteType", remoteType);
+      }
+
+      browser.changeRemoteness({ remoteType });
+      browser.construct();
+    }
+  }
+
+  async loadTestUrl(win, url, timeout) {
+    const browsingContext = this.driver.getBrowsingContext({ top: true });
+    const webProgress = browsingContext.webProgress;
+
+    lazy.logger.debug(`Starting load of ${url}`);
+    if (this.lastURL === url) {
+      lazy.logger.debug(`Refreshing page`);
+      await lazy.navigate.waitForNavigationCompleted(this.driver, () => {
+        lazy.navigate.refresh(browsingContext);
+      });
+    } else {
+      // HACK: DocumentLoadListener currently doesn't know how to
+      // process-switch loads in a non-tabbed <browser>. We need to manually
+      // set the browser's remote type in order to ensure that the load
+      // happens in the correct process.
+      //
+      // See bug 1636169.
+      this.updateBrowserRemotenessByURL(win.gBrowser, url);
+      lazy.navigate.navigateTo(browsingContext, url);
+
+      this.lastURL = url;
+    }
+
+    this.ensureFocus(win);
+
+    // TODO: Move all the wait logic into the parent process (bug 1669787)
+    let isReftestReady = false;
+    while (!isReftestReady) {
+      // Note: We cannot compare the URL here. Before the navigation is complete
+      // currentWindowGlobal.documentURI.spec will still point to the old URL.
+      const actor =
+        webProgress.browsingContext.currentWindowGlobal.getActor(
+          "MarionetteReftest"
+        );
+      isReftestReady = await actor.reftestWait(url, this.useRemoteTabs);
+    }
+  }
+
+  async screenshot(win, url, timeout) {
+    // On windows the above doesn't *actually* set the window to be the
+    // reftest size; but *does* set the content area to be the right size;
+    // the window is given some extra borders that aren't explicable from CSS
+    let browserRect = win.gBrowser.getBoundingClientRect();
+    let canvas = null;
+    let remainingCount = this.urlCount.get(url) || 1;
+    let cache = remainingCount > 1;
+    let cacheKey = browserRect.width + "x" + browserRect.height;
+    lazy.logger.debug(
+      `screenshot ${url} remainingCount: ` +
+        `${remainingCount} cache: ${cache} cacheKey: ${cacheKey}`
+    );
+    let reuseCanvas = false;
+    let sizedCache = this.canvasCache.get(cacheKey);
+    if (sizedCache.has(url)) {
+      lazy.logger.debug(`screenshot ${url} taken from cache`);
+      canvas = sizedCache.get(url);
+      if (!cache) {
+        sizedCache.delete(url);
+      }
+    } else {
+      let canvasPool = sizedCache.get(null);
+      if (canvasPool.length) {
+        lazy.logger.debug("reusing canvas from canvas pool");
+        canvas = canvasPool.pop();
+      } else {
+        lazy.logger.debug("using new canvas");
+        canvas = null;
+      }
+      reuseCanvas = !cache;
+
+      let ctxInterface = win.CanvasRenderingContext2D;
+      let flags =
+        ctxInterface.DRAWWINDOW_DRAW_CARET |
+        ctxInterface.DRAWWINDOW_DRAW_VIEW |
+        ctxInterface.DRAWWINDOW_USE_WIDGET_LAYERS;
+
+      if (
+        !(
+          0 <= browserRect.left &&
+          0 <= browserRect.top &&
+          win.innerWidth >= browserRect.width &&
+          win.innerHeight >= browserRect.height
+        )
+      ) {
+        lazy.logger.error(`Invalid window dimensions:
+browserRect.left: ${browserRect.left}
+browserRect.top: ${browserRect.top}
+win.innerWidth: ${win.innerWidth}
+browserRect.width: ${browserRect.width}
+win.innerHeight: ${win.innerHeight}
+browserRect.height: ${browserRect.height}`);
+        throw new Error("Window has incorrect dimensions");
+      }
+
+      url = new URL(url).href; // normalize the URL
+
+      await this.loadTestUrl(win, url, timeout);
+
+      canvas = await lazy.capture.canvas(
+        win,
+        win.docShell.browsingContext,
+        0, // left
+        0, // top
+        browserRect.width,
+        browserRect.height,
+        { canvas, flags, readback: true }
+      );
+    }
+    if (
+      canvas.width !== browserRect.width ||
+      canvas.height !== browserRect.height
+    ) {
+      lazy.logger.warn(
+        `Canvas dimensions changed to ${canvas.width}x${canvas.height}`
+      );
+      reuseCanvas = false;
+      cache = false;
+    }
+    if (cache) {
+      sizedCache.set(url, canvas);
+    }
+    this.urlCount.set(url, remainingCount - 1);
+    return { canvas, reuseCanvas };
+  }
+
+  async screenshotPaginated(win, url, timeout, pageRanges) {
+    url = new URL(url).href; // normalize the URL
+    await this.loadTestUrl(win, url, timeout);
+
+    const [width, height] = [DEFAULT_PAGE_WIDTH, DEFAULT_PAGE_HEIGHT];
+    const margin = DEFAULT_PAGE_MARGIN;
+    const settings = lazy.print.addDefaultSettings({
+      page: {
+        width,
+        height,
+      },
+      margin: {
+        left: margin,
+        right: margin,
+        top: margin,
+        bottom: margin,
+      },
+      shrinkToFit: false,
+      background: true,
+    });
+    const printSettings = lazy.print.getPrintSettings(settings);
+
+    const binaryString = await lazy.print.printToBinaryString(
+      win.gBrowser.browsingContext,
+      printSettings
+    );
+
+    try {
+      const pdf = await this.loadPdf(binaryString);
+      let pages = this.getPages(pageRanges, url, pdf.numPages);
+      return [this.renderPages(pdf, pages), pages.size];
+    } catch (e) {
+      lazy.logger.warn(`Loading of pdf failed`);
+      throw e;
+    }
+  }
+
+  async loadPdfJs() {
+    // Ensure pdf.js is loaded in the opener window
+    await new Promise((resolve, reject) => {
+      const doc = this.parentWindow.document;
+      const script = doc.createElement("script");
+      script.src = "resource://pdf.js/build/pdf.js";
+      script.onload = resolve;
+      script.onerror = () => reject(new Error("pdfjs load failed"));
+      doc.documentElement.appendChild(script);
+    });
+    this.parentWindow.pdfjsLib.GlobalWorkerOptions.workerSrc =
+      "resource://pdf.js/build/pdf.worker.js";
+  }
+
+  async loadPdf(data) {
+    return this.parentWindow.pdfjsLib.getDocument({ data }).promise;
+  }
+
+  async *renderPages(pdf, pages) {
+    let canvas = null;
+    for (let pageNumber = 1; pageNumber <= pdf.numPages; pageNumber++) {
+      if (!pages.has(pageNumber)) {
+        lazy.logger.info(`Skipping page ${pageNumber}/${pdf.numPages}`);
+        continue;
+      }
+      lazy.logger.info(`Rendering page ${pageNumber}/${pdf.numPages}`);
+      let page = await pdf.getPage(pageNumber);
+      let viewport = page.getViewport({ scale: DEFAULT_PDF_RESOLUTION });
+      // Prepare canvas using PDF page dimensions
+      if (canvas === null) {
+        canvas = this.parentWindow.document.createElementNS(XHTML_NS, "canvas");
+        canvas.height = viewport.height;
+        canvas.width = viewport.width;
+      }
+
+      // Render PDF page into canvas context
+      let context = canvas.getContext("2d");
+      let renderContext = {
+        canvasContext: context,
+        viewport,
+      };
+      await page.render(renderContext).promise;
+      yield { canvas, reuseCanvas: false };
+    }
+  }
+
+  getPages(pageRanges, url, totalPages) {
+    // Extract test id from URL without parsing
+    let afterHost = url.slice(url.indexOf(":") + 3);
+    afterHost = afterHost.slice(afterHost.indexOf("/"));
+    const ranges = pageRanges[afterHost];
+    let rv = new Set();
+
+    if (!ranges) {
+      for (let i = 1; i <= totalPages; i++) {
+        rv.add(i);
+      }
+      return rv;
+    }
+
+    for (let rangePart of ranges) {
+      if (rangePart.length === 1) {
+        rv.add(rangePart[0]);
+      } else {
+        if (rangePart.length !== 2) {
+          throw new Error(
+            `Page ranges must be <int> or <int> '-' <int>, got ${rangePart}`
+          );
+        }
+        let [lower, upper] = rangePart;
+        if (lower === null) {
+          lower = 1;
+        }
+        if (upper === null) {
+          upper = totalPages;
+        }
+        for (let i = lower; i <= upper; i++) {
+          rv.add(i);
+        }
+      }
+    }
+    return rv;
+  }
+};
+
+class DefaultMap extends Map {
+  constructor(iterable, defaultFactory) {
+    super(iterable);
+    this.defaultFactory = defaultFactory;
+  }
+
+  get(key) {
+    if (this.has(key)) {
+      return super.get(key);
+    }
+
+    let v = this.defaultFactory();
+    this.set(key, v);
+    return v;
+  }
+}