Adding upstream version 110.0.1.upstream/110.0.1upstream

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

23 files changed, 1414 insertions, 0 deletions

diff --git a/browser/components/shell/test/browser.ini b/browser/components/shell/test/browser.ini
new file mode 100644
index 0000000000..e3193bc466
--- /dev/null
+++ b/browser/components/shell/test/browser.ini
@@ -0,0 +1,49 @@
+[DEFAULT]
+
+[browser_420786.js]
+skip-if = os != "linux"
+[browser_633221.js]
+skip-if = os != "linux"
+[browser_1119088.js]
+support-files =
+  mac_desktop_image.py
+skip-if = os != "mac" || verify
+[browser_doesAppNeedPin.js]
+[browser_setDefaultBrowser.js]
+[browser_setDefaultPDFHandler.js]
+run-if = os == "win" && os_version != "6.1"
+reason = Test is Windows 10+.
+[browser_setDesktopBackgroundPreview.js]
+[browser_headless_screenshot_1.js]
+support-files =
+  head.js
+  headless.html
+skip-if = os == 'win' || ccov || tsan #Bug 1429950 , Bug 1583315, Bug 1696109, Bug 1701449
+[browser_headless_screenshot_2.js]
+support-files =
+  head.js
+  headless.html
+skip-if = os == 'win' || ccov|| tsan #Bug 1429950 , Bug 1583315, Bug 1696109, Bug 1701449
+[browser_headless_screenshot_3.js]
+support-files =
+  head.js
+  headless.html
+skip-if = os == 'win' || ccov || tsan #Bug 1429950 , Bug 1583315, Bug 1696109, Bug 1701449
+[browser_headless_screenshot_4.js]
+support-files =
+  head.js
+  headless.html
+skip-if = os == 'win' || ccov || tsan #Bug 1429950 , Bug 1583315, Bug 1696109, Bug 1701449
+[browser_headless_screenshot_redirect.js]
+support-files =
+  head.js
+  headless.html
+  headless_redirect.html
+  headless_redirect.html^headers^
+skip-if = os == 'win' || ccov || tsan #Bug 1429950 , Bug 1583315, Bug 1696109, Bug 1701449
+[browser_headless_screenshot_cross_origin.js]
+support-files =
+  head.js
+  headless_cross_origin.html
+  headless_iframe.html
+skip-if = os == 'win' || ccov || tsan #Bug 1429950 , Bug 1583315, Bug 1696109, Bug 1701449
diff --git a/browser/components/shell/test/browser_1119088.js b/browser/components/shell/test/browser_1119088.js
new file mode 100644
index 0000000000..fd95fb94af
--- /dev/null
+++ b/browser/components/shell/test/browser_1119088.js
@@ -0,0 +1,170 @@
+// Where we save the desktop background to (~/Pictures).
+const NS_OSX_PICTURE_DOCUMENTS_DIR = "Pct";
+
+// Paths used to run the CLI command (python script) that is used to
+// 1) check the desktop background image matches what we set it to via
+//    nsIShellService::setDesktopBackground() and
+// 2) revert the desktop background image to the OS default
+const kPythonPath = "/usr/bin/python";
+const kDesktopCheckerScriptPath =
+  "browser/browser/components/shell/test/mac_desktop_image.py";
+const kDefaultBackgroundImage_10_14 =
+  "/Library/Desktop Pictures/Solid Colors/Teal.png";
+const kDefaultBackgroundImage_10_15 =
+  "/System/Library/Desktop Pictures/Solid Colors/Teal.png";
+
+ChromeUtils.defineESModuleGetters(this, {
+  FileUtils: "resource://gre/modules/FileUtils.sys.mjs",
+});
+
+function getPythonExecutableFile() {
+  let python = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsIFile);
+  python.initWithPath(kPythonPath);
+  return python;
+}
+
+function createProcess() {
+  return Cc["@mozilla.org/process/util;1"].createInstance(Ci.nsIProcess);
+}
+
+// Use a CLI command to set the desktop background to |imagePath|. Returns the
+// exit code of the CLI command which reflects whether or not the background
+// image was successfully set. Returns 0 on success.
+function setDesktopBackgroundCLI(imagePath) {
+  let setBackgroundProcess = createProcess();
+  setBackgroundProcess.init(getPythonExecutableFile());
+  let args = [
+    kDesktopCheckerScriptPath,
+    "--verbose",
+    "--set-background-image",
+    imagePath,
+  ];
+  setBackgroundProcess.run(true, args, args.length);
+  return setBackgroundProcess.exitValue;
+}
+
+// Check the desktop background is |imagePath| using a CLI command.
+// Returns the exit code of the CLI command which reflects whether or not
+// the provided image path matches the path of the current desktop background
+// image. A return value of 0 indicates success/match.
+function checkDesktopBackgroundCLI(imagePath) {
+  let checkBackgroundProcess = createProcess();
+  checkBackgroundProcess.init(getPythonExecutableFile());
+  let args = [
+    kDesktopCheckerScriptPath,
+    "--verbose",
+    "--check-background-image",
+    imagePath,
+  ];
+  checkBackgroundProcess.run(true, args, args.length);
+  return checkBackgroundProcess.exitValue;
+}
+
+// Use the python script to set/check the desktop background is |imagePath|
+function setAndCheckDesktopBackgroundCLI(imagePath) {
+  Assert.ok(FileUtils.File(imagePath).exists(), `${imagePath} exists`);
+
+  let setExitCode = setDesktopBackgroundCLI(imagePath);
+  Assert.ok(setExitCode == 0, `Setting background via CLI to ${imagePath}`);
+
+  let checkExitCode = checkDesktopBackgroundCLI(imagePath);
+  Assert.ok(checkExitCode == 0, `Checking background via CLI is ${imagePath}`);
+}
+
+// Restore the automation default background image. i.e., the default used
+// in the automated test environment, not the OS default.
+function restoreDefaultBackground() {
+  let defaultBackgroundPath;
+  if (AppConstants.isPlatformAndVersionAtLeast("macosx", 19)) {
+    defaultBackgroundPath = kDefaultBackgroundImage_10_15;
+  } else {
+    defaultBackgroundPath = kDefaultBackgroundImage_10_14;
+  }
+  setAndCheckDesktopBackgroundCLI(defaultBackgroundPath);
+}
+
+/**
+ * Tests "Set As Desktop Background" platform implementation on macOS.
+ *
+ * Sets the desktop background image to the browser logo from the about:logo
+ * page and verifies it was set successfully. Setting the desktop background
+ * (which uses the nsIShellService::setDesktopBackground() interface method)
+ * downloads the image to ~/Pictures using a unique file name and sets the
+ * desktop background to the downloaded file leaving the download in place.
+ * After setDesktopBackground() is called, the test uses a python script to
+ * validate that the current desktop background is in fact set to the
+ * downloaded logo.
+ */
+add_task(async function() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: "about:logo",
+    },
+    async browser => {
+      let dirSvc = Cc["@mozilla.org/file/directory_service;1"].getService(
+        Ci.nsIDirectoryServiceProvider
+      );
+      let uuidGenerator = Services.uuid;
+      let shellSvc = Cc["@mozilla.org/browser/shell-service;1"].getService(
+        Ci.nsIShellService
+      );
+
+      // Ensure we are starting with the default background. Log a
+      // failure if we can not set the background to the default, but
+      // ignore the case where the background is not already set as that
+      // that may be due to a previous test failure.
+      restoreDefaultBackground();
+
+      // Generate a UUID (with non-alphanumberic characters removed) to build
+      // up a filename for the desktop background. Use a UUID to distinguish
+      // between runs so we won't be confused by images that were not properly
+      // cleaned up after previous runs.
+      let uuid = uuidGenerator
+        .generateUUID()
+        .toString()
+        .replace(/\W/g, "");
+
+      // Set the background image path to be $HOME/Pictures/<UUID>.png.
+      // nsIShellService.setDesktopBackground() downloads the image to this
+      // path and then sets it as the desktop background image, leaving the
+      // image in place.
+      let backgroundImage = dirSvc.getFile(NS_OSX_PICTURE_DOCUMENTS_DIR, {});
+      backgroundImage.append(uuid + ".png");
+      if (backgroundImage.exists()) {
+        backgroundImage.remove(false);
+      }
+
+      // For simplicity, we're going to reach in and access the image on the
+      // page directly, which means the page shouldn't be running in a remote
+      // browser. Thankfully, about:logo runs in the parent process for now.
+      Assert.ok(
+        !gBrowser.selectedBrowser.isRemoteBrowser,
+        "image can be accessed synchronously from the parent process"
+      );
+      let image = gBrowser.selectedBrowser.contentDocument.images[0];
+
+      info(`Setting/saving desktop background to ${backgroundImage.path}`);
+
+      // Saves the file in ~/Pictures
+      shellSvc.setDesktopBackground(image, 0, backgroundImage.leafName);
+
+      await BrowserTestUtils.waitForCondition(() => backgroundImage.exists());
+      info(`${backgroundImage.path} downloaded`);
+      Assert.ok(
+        FileUtils.File(backgroundImage.path).exists(),
+        `${backgroundImage.path} exists`
+      );
+
+      // Check that the desktop background image is the image we set above.
+      let exitCode = checkDesktopBackgroundCLI(backgroundImage.path);
+      Assert.ok(exitCode == 0, `background should be ${backgroundImage.path}`);
+
+      // Restore the background image to the Mac default.
+      restoreDefaultBackground();
+
+      // We no longer need the downloaded image.
+      backgroundImage.remove(false);
+    }
+  );
+});
diff --git a/browser/components/shell/test/browser_420786.js b/browser/components/shell/test/browser_420786.js
new file mode 100644
index 0000000000..3443011189
--- /dev/null
+++ b/browser/components/shell/test/browser_420786.js
@@ -0,0 +1,105 @@
+const DG_BACKGROUND = "/desktop/gnome/background";
+const DG_IMAGE_KEY = DG_BACKGROUND + "/picture_filename";
+const DG_OPTION_KEY = DG_BACKGROUND + "/picture_options";
+const DG_DRAW_BG_KEY = DG_BACKGROUND + "/draw_background";
+
+const GS_BG_SCHEMA = "org.gnome.desktop.background";
+const GS_IMAGE_KEY = "picture-uri";
+const GS_OPTION_KEY = "picture-options";
+const GS_DRAW_BG_KEY = "draw-background";
+
+add_task(async function() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: "about:logo",
+    },
+    browser => {
+      var brandName = Services.strings
+        .createBundle("chrome://branding/locale/brand.properties")
+        .GetStringFromName("brandShortName");
+
+      var dirSvc = Cc["@mozilla.org/file/directory_service;1"].getService(
+        Ci.nsIDirectoryServiceProvider
+      );
+      var homeDir = dirSvc.getFile("Home", {});
+
+      var wpFile = homeDir.clone();
+      wpFile.append(brandName + "_wallpaper.png");
+
+      // Backup the existing wallpaper so that this test doesn't change the user's
+      // settings.
+      var wpFileBackup = homeDir.clone();
+      wpFileBackup.append(brandName + "_wallpaper.png.backup");
+
+      if (wpFileBackup.exists()) {
+        wpFileBackup.remove(false);
+      }
+
+      if (wpFile.exists()) {
+        wpFile.copyTo(null, wpFileBackup.leafName);
+      }
+
+      var shell = Cc["@mozilla.org/browser/shell-service;1"].getService(
+        Ci.nsIShellService
+      );
+
+      // For simplicity, we're going to reach in and access the image on the
+      // page directly, which means the page shouldn't be running in a remote
+      // browser. Thankfully, about:logo runs in the parent process for now.
+      Assert.ok(
+        !gBrowser.selectedBrowser.isRemoteBrowser,
+        "image can be accessed synchronously from the parent process"
+      );
+
+      var image = content.document.images[0];
+
+      let checkWallpaper, restoreSettings;
+      try {
+        // Try via GSettings first
+        const gsettings = Cc["@mozilla.org/gsettings-service;1"]
+          .getService(Ci.nsIGSettingsService)
+          .getCollectionForSchema(GS_BG_SCHEMA);
+
+        const prevImage = gsettings.getString(GS_IMAGE_KEY);
+        const prevOption = gsettings.getString(GS_OPTION_KEY);
+        const prevDrawBG = gsettings.getBoolean(GS_DRAW_BG_KEY);
+
+        checkWallpaper = function(position, expectedGSettingsPosition) {
+          shell.setDesktopBackground(image, position, "");
+          ok(wpFile.exists(), "Wallpaper was written to disk");
+          is(
+            gsettings.getString(GS_IMAGE_KEY),
+            encodeURI("file://" + wpFile.path),
+            "Wallpaper file GSettings key is correct"
+          );
+          is(
+            gsettings.getString(GS_OPTION_KEY),
+            expectedGSettingsPosition,
+            "Wallpaper position GSettings key is correct"
+          );
+        };
+
+        restoreSettings = function() {
+          gsettings.setString(GS_IMAGE_KEY, prevImage);
+          gsettings.setString(GS_OPTION_KEY, prevOption);
+          gsettings.setBoolean(GS_DRAW_BG_KEY, prevDrawBG);
+        };
+      } catch (e) {}
+
+      checkWallpaper(Ci.nsIShellService.BACKGROUND_TILE, "wallpaper");
+      checkWallpaper(Ci.nsIShellService.BACKGROUND_STRETCH, "stretched");
+      checkWallpaper(Ci.nsIShellService.BACKGROUND_CENTER, "centered");
+      checkWallpaper(Ci.nsIShellService.BACKGROUND_FILL, "zoom");
+      checkWallpaper(Ci.nsIShellService.BACKGROUND_FIT, "scaled");
+      checkWallpaper(Ci.nsIShellService.BACKGROUND_SPAN, "spanned");
+
+      restoreSettings();
+
+      // Restore files
+      if (wpFileBackup.exists()) {
+        wpFileBackup.moveTo(null, wpFile.leafName);
+      }
+    }
+  );
+});
diff --git a/browser/components/shell/test/browser_633221.js b/browser/components/shell/test/browser_633221.js
new file mode 100644
index 0000000000..b61aeba6fa
--- /dev/null
+++ b/browser/components/shell/test/browser_633221.js
@@ -0,0 +1,15 @@
+const { ShellService } = ChromeUtils.import(
+  "resource:///modules/ShellService.jsm"
+);
+
+function test() {
+  ShellService.setDefaultBrowser(true, false);
+  ok(
+    ShellService.isDefaultBrowser(true, false),
+    "we got here and are the default browser"
+  );
+  ok(
+    ShellService.isDefaultBrowser(true, true),
+    "we got here and are the default browser"
+  );
+}
diff --git a/browser/components/shell/test/browser_doesAppNeedPin.js b/browser/components/shell/test/browser_doesAppNeedPin.js
new file mode 100644
index 0000000000..1ecb6cc108
--- /dev/null
+++ b/browser/components/shell/test/browser_doesAppNeedPin.js
@@ -0,0 +1,54 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+XPCOMUtils.defineLazyModuleGetters(this, {
+  ExperimentAPI: "resource://nimbus/ExperimentAPI.jsm",
+  ExperimentFakes: "resource://testing-common/NimbusTestUtils.jsm",
+  NimbusFeatures: "resource://nimbus/ExperimentAPI.jsm",
+});
+
+registerCleanupFunction(() => {
+  ExperimentAPI._store._deleteForTests("shellService");
+});
+
+let defaultValue;
+add_task(async function default_need() {
+  defaultValue = await ShellService.doesAppNeedPin();
+
+  Assert.ok(defaultValue !== undefined, "Got a default app need pin value");
+});
+
+add_task(async function remote_disable() {
+  if (defaultValue === false) {
+    info("Default pin already false, so nothing to test");
+    return;
+  }
+
+  let doCleanup = await ExperimentFakes.enrollWithRollout({
+    featureId: NimbusFeatures.shellService.featureId,
+    value: { disablePin: true, enabled: true },
+  });
+
+  Assert.equal(
+    await ShellService.doesAppNeedPin(),
+    false,
+    "Pinning disabled via nimbus"
+  );
+
+  await doCleanup();
+});
+
+add_task(async function restore_default() {
+  if (defaultValue === undefined) {
+    info("No default pin value set, so nothing to test");
+    return;
+  }
+
+  ExperimentAPI._store._deleteForTests("shellService");
+
+  Assert.equal(
+    await ShellService.doesAppNeedPin(),
+    defaultValue,
+    "Pinning restored to original"
+  );
+});
diff --git a/browser/components/shell/test/browser_headless_screenshot_1.js b/browser/components/shell/test/browser_headless_screenshot_1.js
new file mode 100644
index 0000000000..bde8c53e5e
--- /dev/null
+++ b/browser/components/shell/test/browser_headless_screenshot_1.js
@@ -0,0 +1,74 @@
+"use strict";
+
+add_task(async function() {
+  // Test all four basic variations of the "screenshot" argument
+  // when a file path is specified.
+  await testFileCreationPositive(
+    [
+      "-url",
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+      "-screenshot",
+      screenshotPath,
+    ],
+    screenshotPath
+  );
+  await testFileCreationPositive(
+    [
+      "-url",
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+      `-screenshot=${screenshotPath}`,
+    ],
+    screenshotPath
+  );
+  await testFileCreationPositive(
+    [
+      "-url",
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+      "--screenshot",
+      screenshotPath,
+    ],
+    screenshotPath
+  );
+  await testFileCreationPositive(
+    [
+      "-url",
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+      `--screenshot=${screenshotPath}`,
+    ],
+    screenshotPath
+  );
+
+  // Test when the requested URL redirects
+  await testFileCreationPositive(
+    [
+      "-url",
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless_redirect.html",
+      "-screenshot",
+      screenshotPath,
+    ],
+    screenshotPath
+  );
+
+  // Test with additional command options
+  await testFileCreationPositive(
+    [
+      "-url",
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+      "-screenshot",
+      screenshotPath,
+      "-attach-console",
+    ],
+    screenshotPath
+  );
+  await testFileCreationPositive(
+    [
+      "-url",
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+      "-attach-console",
+      "-screenshot",
+      screenshotPath,
+      "-headless",
+    ],
+    screenshotPath
+  );
+});
diff --git a/browser/components/shell/test/browser_headless_screenshot_2.js b/browser/components/shell/test/browser_headless_screenshot_2.js
new file mode 100644
index 0000000000..063fcfe01e
--- /dev/null
+++ b/browser/components/shell/test/browser_headless_screenshot_2.js
@@ -0,0 +1,48 @@
+"use strict";
+add_task(async function() {
+  const cwdScreenshotPath = PathUtils.join(
+    Services.dirsvc.get("CurWorkD", Ci.nsIFile).path,
+    "screenshot.png"
+  );
+
+  // Test variations of the "screenshot" argument when a file path
+  // isn't specified.
+  await testFileCreationPositive(
+    [
+      "-screenshot",
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+    ],
+    cwdScreenshotPath
+  );
+  await testFileCreationPositive(
+    [
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+      "-screenshot",
+    ],
+    cwdScreenshotPath
+  );
+  await testFileCreationPositive(
+    [
+      "--screenshot",
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+    ],
+    cwdScreenshotPath
+  );
+  await testFileCreationPositive(
+    [
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+      "--screenshot",
+    ],
+    cwdScreenshotPath
+  );
+
+  // Test with additional command options
+  await testFileCreationPositive(
+    [
+      "--screenshot",
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+      "-attach-console",
+    ],
+    cwdScreenshotPath
+  );
+});
diff --git a/browser/components/shell/test/browser_headless_screenshot_3.js b/browser/components/shell/test/browser_headless_screenshot_3.js
new file mode 100644
index 0000000000..32c0f91768
--- /dev/null
+++ b/browser/components/shell/test/browser_headless_screenshot_3.js
@@ -0,0 +1,59 @@
+"use strict";
+
+add_task(async function() {
+  const cwdScreenshotPath = PathUtils.join(
+    Services.dirsvc.get("CurWorkD", Ci.nsIFile).path,
+    "screenshot.png"
+  );
+
+  // Test invalid URL arguments (either no argument or too many arguments).
+  await testFileCreationNegative(["-screenshot"], cwdScreenshotPath);
+  await testFileCreationNegative(
+    [
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+      "http://mochi.test:8888/headless.html",
+      "-screenshot",
+    ],
+    cwdScreenshotPath
+  );
+
+  // Test all four basic variations of the "window-size" argument.
+  await testFileCreationPositive(
+    [
+      "-url",
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+      "-screenshot",
+      "-window-size",
+      "800",
+    ],
+    cwdScreenshotPath
+  );
+  await testFileCreationPositive(
+    [
+      "-url",
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+      "-screenshot",
+      "-window-size=800",
+    ],
+    cwdScreenshotPath
+  );
+  await testFileCreationPositive(
+    [
+      "-url",
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+      "-screenshot",
+      "--window-size",
+      "800",
+    ],
+    cwdScreenshotPath
+  );
+  await testFileCreationPositive(
+    [
+      "-url",
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+      "-screenshot",
+      "--window-size=800",
+    ],
+    cwdScreenshotPath
+  );
+});
diff --git a/browser/components/shell/test/browser_headless_screenshot_4.js b/browser/components/shell/test/browser_headless_screenshot_4.js
new file mode 100644
index 0000000000..0e3493ef67
--- /dev/null
+++ b/browser/components/shell/test/browser_headless_screenshot_4.js
@@ -0,0 +1,31 @@
+"use strict";
+
+add_task(async function() {
+  const cwdScreenshotPath = PathUtils.join(
+    Services.dirsvc.get("CurWorkD", Ci.nsIFile).path,
+    "screenshot.png"
+  );
+  // Test other variations of the "window-size" argument.
+  await testWindowSizePositive(800, 600);
+  await testWindowSizePositive(1234);
+  await testFileCreationNegative(
+    [
+      "-url",
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+      "-screenshot",
+      "-window-size",
+      "hello",
+    ],
+    cwdScreenshotPath
+  );
+  await testFileCreationNegative(
+    [
+      "-url",
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+      "-screenshot",
+      "-window-size",
+      "800,",
+    ],
+    cwdScreenshotPath
+  );
+});
diff --git a/browser/components/shell/test/browser_headless_screenshot_cross_origin.js b/browser/components/shell/test/browser_headless_screenshot_cross_origin.js
new file mode 100644
index 0000000000..aca7fb2cbe
--- /dev/null
+++ b/browser/components/shell/test/browser_headless_screenshot_cross_origin.js
@@ -0,0 +1,9 @@
+"use strict";
+
+add_task(async function() {
+  // Test cross origin iframes work.
+  await testGreen(
+    "http://mochi.test:8888/browser/browser/components/shell/test/headless_cross_origin.html",
+    screenshotPath
+  );
+});
diff --git a/browser/components/shell/test/browser_headless_screenshot_redirect.js b/browser/components/shell/test/browser_headless_screenshot_redirect.js
new file mode 100644
index 0000000000..d34dcf6e69
--- /dev/null
+++ b/browser/components/shell/test/browser_headless_screenshot_redirect.js
@@ -0,0 +1,14 @@
+"use strict";
+
+add_task(async function() {
+  // Test when the requested URL redirects
+  await testFileCreationPositive(
+    [
+      "-url",
+      "http://mochi.test:8888/browser/browser/components/shell/test/headless_redirect.html",
+      "-screenshot",
+      screenshotPath,
+    ],
+    screenshotPath
+  );
+});
diff --git a/browser/components/shell/test/browser_setDefaultBrowser.js b/browser/components/shell/test/browser_setDefaultBrowser.js
new file mode 100644
index 0000000000..8a8b4d5913
--- /dev/null
+++ b/browser/components/shell/test/browser_setDefaultBrowser.js
@@ -0,0 +1,90 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+XPCOMUtils.defineLazyModuleGetters(this, {
+  ExperimentAPI: "resource://nimbus/ExperimentAPI.jsm",
+  ExperimentFakes: "resource://testing-common/NimbusTestUtils.jsm",
+  NimbusFeatures: "resource://nimbus/ExperimentAPI.jsm",
+  sinon: "resource://testing-common/Sinon.jsm",
+});
+
+const userChoiceStub = sinon
+  .stub(ShellService, "setAsDefaultUserChoice")
+  .resolves();
+const setDefaultStub = sinon.stub();
+const shellStub = sinon
+  .stub(ShellService, "shellService")
+  .value({ setDefaultBrowser: setDefaultStub });
+registerCleanupFunction(() => {
+  userChoiceStub.restore();
+  shellStub.restore();
+
+  ExperimentAPI._store._deleteForTests("shellService");
+});
+
+let defaultUserChoice;
+add_task(async function need_user_choice() {
+  ShellService.setDefaultBrowser();
+  defaultUserChoice = userChoiceStub.called;
+
+  Assert.ok(
+    defaultUserChoice !== undefined,
+    "Decided which default browser method to use"
+  );
+  Assert.equal(
+    setDefaultStub.notCalled,
+    defaultUserChoice,
+    "Only one default behavior was used"
+  );
+});
+
+add_task(async function remote_disable() {
+  if (defaultUserChoice === false) {
+    info("Default behavior already not user choice, so nothing to test");
+    return;
+  }
+
+  userChoiceStub.resetHistory();
+  setDefaultStub.resetHistory();
+  let doCleanup = await ExperimentFakes.enrollWithRollout({
+    featureId: NimbusFeatures.shellService.featureId,
+    value: {
+      setDefaultBrowserUserChoice: false,
+      enabled: true,
+    },
+  });
+
+  ShellService.setDefaultBrowser();
+
+  Assert.ok(
+    userChoiceStub.notCalled,
+    "Set default with user choice disabled via nimbus"
+  );
+  Assert.ok(setDefaultStub.called, "Used plain set default insteead");
+
+  await doCleanup();
+});
+
+add_task(async function restore_default() {
+  if (defaultUserChoice === undefined) {
+    info("No default user choice behavior set, so nothing to test");
+    return;
+  }
+
+  userChoiceStub.resetHistory();
+  setDefaultStub.resetHistory();
+  ExperimentAPI._store._deleteForTests("shellService");
+
+  ShellService.setDefaultBrowser();
+
+  Assert.equal(
+    userChoiceStub.called,
+    defaultUserChoice,
+    "Set default with user choice restored to original"
+  );
+  Assert.equal(
+    setDefaultStub.notCalled,
+    defaultUserChoice,
+    "Plain set default behavior restored to original"
+  );
+});
diff --git a/browser/components/shell/test/browser_setDefaultPDFHandler.js b/browser/components/shell/test/browser_setDefaultPDFHandler.js
new file mode 100644
index 0000000000..2041ac275d
--- /dev/null
+++ b/browser/components/shell/test/browser_setDefaultPDFHandler.js
@@ -0,0 +1,221 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+XPCOMUtils.defineLazyModuleGetters(this, {
+  ExperimentAPI: "resource://nimbus/ExperimentAPI.jsm",
+  ExperimentFakes: "resource://testing-common/NimbusTestUtils.jsm",
+  NimbusFeatures: "resource://nimbus/ExperimentAPI.jsm",
+  sinon: "resource://testing-common/Sinon.jsm",
+});
+
+XPCOMUtils.defineLazyServiceGetter(
+  this,
+  "XreDirProvider",
+  "@mozilla.org/xre/directory-provider;1",
+  "nsIXREDirProvider"
+);
+
+const _callExternalDefaultBrowserAgentStub = sinon
+  .stub(ShellService, "_callExternalDefaultBrowserAgent")
+  .callsFake(async () => ({
+    async wait() {
+      return { exitCode: 0 };
+    },
+  }));
+
+const _userChoiceImpossibleTelemetryResultStub = sinon
+  .stub(ShellService, "_userChoiceImpossibleTelemetryResult")
+  .callsFake(() => null);
+
+// Ensure we don't fall back to a real implementation.
+const setDefaultStub = sinon.stub();
+// We'll dynamically update this as needed during the tests.
+const queryCurrentDefaultHandlerForStub = sinon.stub();
+const shellStub = sinon.stub(ShellService, "shellService").value({
+  setDefaultBrowser: setDefaultStub,
+  queryCurrentDefaultHandlerFor: queryCurrentDefaultHandlerForStub,
+});
+
+registerCleanupFunction(() => {
+  _callExternalDefaultBrowserAgentStub.restore();
+  _userChoiceImpossibleTelemetryResultStub.restore();
+  shellStub.restore();
+
+  ExperimentAPI._store._deleteForTests("shellService");
+});
+
+add_task(async function ready() {
+  await ExperimentAPI.ready();
+});
+
+// Everything here is Windows 10+.
+Assert.ok(
+  AppConstants.isPlatformAndVersionAtLeast("win", "10"),
+  "Windows version 10+"
+);
+
+add_task(async function remoteEnableWithPDF() {
+  let doCleanup = await ExperimentFakes.enrollWithRollout({
+    featureId: NimbusFeatures.shellService.featureId,
+    value: {
+      setDefaultBrowserUserChoice: true,
+      setDefaultPDFHandlerOnlyReplaceBrowsers: false,
+      setDefaultPDFHandler: true,
+      enabled: true,
+    },
+  });
+
+  Assert.equal(
+    NimbusFeatures.shellService.getVariable("setDefaultBrowserUserChoice"),
+    true
+  );
+  Assert.equal(
+    NimbusFeatures.shellService.getVariable("setDefaultPDFHandler"),
+    true
+  );
+
+  _callExternalDefaultBrowserAgentStub.resetHistory();
+  ShellService.setDefaultBrowser();
+
+  const aumi = XreDirProvider.getInstallHash();
+  Assert.ok(_callExternalDefaultBrowserAgentStub.called);
+  Assert.deepEqual(_callExternalDefaultBrowserAgentStub.firstCall.args, [
+    {
+      arguments: [
+        "set-default-browser-user-choice",
+        aumi,
+        ".pdf",
+        "FirefoxPDF",
+      ],
+    },
+  ]);
+
+  await doCleanup();
+});
+
+add_task(async function remoteEnableWithPDF_testOnlyReplaceBrowsers() {
+  let doCleanup = await ExperimentFakes.enrollWithRollout({
+    featureId: NimbusFeatures.shellService.featureId,
+    value: {
+      setDefaultBrowserUserChoice: true,
+      setDefaultPDFHandlerOnlyReplaceBrowsers: true,
+      setDefaultPDFHandler: true,
+      enabled: true,
+    },
+  });
+
+  Assert.equal(
+    NimbusFeatures.shellService.getVariable("setDefaultBrowserUserChoice"),
+    true
+  );
+  Assert.equal(
+    NimbusFeatures.shellService.getVariable("setDefaultPDFHandler"),
+    true
+  );
+  Assert.equal(
+    NimbusFeatures.shellService.getVariable(
+      "setDefaultPDFHandlerOnlyReplaceBrowsers"
+    ),
+    true
+  );
+
+  const aumi = XreDirProvider.getInstallHash();
+
+  // We'll take the default from a missing association or a known browser.
+  for (let progId of ["", "MSEdgePDF"]) {
+    queryCurrentDefaultHandlerForStub.callsFake(() => progId);
+
+    _callExternalDefaultBrowserAgentStub.resetHistory();
+    ShellService.setDefaultBrowser();
+
+    Assert.ok(_callExternalDefaultBrowserAgentStub.called);
+    Assert.deepEqual(
+      _callExternalDefaultBrowserAgentStub.firstCall.args,
+      [
+        {
+          arguments: [
+            "set-default-browser-user-choice",
+            aumi,
+            ".pdf",
+            "FirefoxPDF",
+          ],
+        },
+      ],
+      `Will take default from missing association or known browser with ProgID '${progId}'`
+    );
+  }
+
+  // But not from a non-browser.
+  queryCurrentDefaultHandlerForStub.callsFake(() => "Acrobat.Document.DC");
+
+  _callExternalDefaultBrowserAgentStub.resetHistory();
+  ShellService.setDefaultBrowser();
+
+  Assert.ok(_callExternalDefaultBrowserAgentStub.called);
+  Assert.deepEqual(
+    _callExternalDefaultBrowserAgentStub.firstCall.args,
+    [{ arguments: ["set-default-browser-user-choice", aumi] }],
+    `Will not take default from non-browser`
+  );
+
+  await doCleanup();
+});
+
+add_task(async function remoteEnableWithoutPDF() {
+  let doCleanup = await ExperimentFakes.enrollWithRollout({
+    featureId: NimbusFeatures.shellService.featureId,
+    value: {
+      setDefaultBrowserUserChoice: true,
+      setDefaultPDFHandler: false,
+      enabled: true,
+    },
+  });
+
+  Assert.equal(
+    NimbusFeatures.shellService.getVariable("setDefaultBrowserUserChoice"),
+    true
+  );
+  Assert.equal(
+    NimbusFeatures.shellService.getVariable("setDefaultPDFHandler"),
+    false
+  );
+
+  _callExternalDefaultBrowserAgentStub.resetHistory();
+  ShellService.setDefaultBrowser();
+
+  const aumi = XreDirProvider.getInstallHash();
+  Assert.ok(_callExternalDefaultBrowserAgentStub.called);
+  Assert.deepEqual(_callExternalDefaultBrowserAgentStub.firstCall.args, [
+    { arguments: ["set-default-browser-user-choice", aumi] },
+  ]);
+
+  await doCleanup();
+});
+
+add_task(async function remoteDisable() {
+  let doCleanup = await ExperimentFakes.enrollWithRollout({
+    featureId: NimbusFeatures.shellService.featureId,
+    value: {
+      setDefaultBrowserUserChoice: false,
+      setDefaultPDFHandler: true,
+      enabled: false,
+    },
+  });
+
+  Assert.equal(
+    NimbusFeatures.shellService.getVariable("setDefaultBrowserUserChoice"),
+    false
+  );
+  Assert.equal(
+    NimbusFeatures.shellService.getVariable("setDefaultPDFHandler"),
+    true
+  );
+
+  _callExternalDefaultBrowserAgentStub.resetHistory();
+  ShellService.setDefaultBrowser();
+
+  Assert.ok(_callExternalDefaultBrowserAgentStub.notCalled);
+  Assert.ok(setDefaultStub.called);
+
+  await doCleanup();
+});
diff --git a/browser/components/shell/test/browser_setDesktopBackgroundPreview.js b/browser/components/shell/test/browser_setDesktopBackgroundPreview.js
new file mode 100644
index 0000000000..fcdf566a8b
--- /dev/null
+++ b/browser/components/shell/test/browser_setDesktopBackgroundPreview.js
@@ -0,0 +1,91 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Check whether the preview image for setDesktopBackground is rendered
+ * correctly, without stretching
+ */
+
+const { ShellService } = ChromeUtils.import(
+  "resource:///modules/ShellService.jsm"
+);
+
+add_task(async function() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: "about:logo",
+    },
+    async browser => {
+      const dialogLoad = BrowserTestUtils.domWindowOpened(null, async win => {
+        await BrowserTestUtils.waitForEvent(win, "load");
+        Assert.equal(
+          win.document.documentElement.getAttribute("windowtype"),
+          "Shell:SetDesktopBackground",
+          "Opened correct window"
+        );
+        return true;
+      });
+
+      const image = content.document.images[0];
+      EventUtils.synthesizeMouseAtCenter(image, { type: "contextmenu" });
+
+      const menu = document.getElementById("contentAreaContextMenu");
+      await BrowserTestUtils.waitForPopupEvent(menu, "shown");
+      const menuClosed = BrowserTestUtils.waitForPopupEvent(menu, "hidden");
+
+      const menuItem = document.getElementById("context-setDesktopBackground");
+      try {
+        menu.activateItem(menuItem);
+      } catch (ex) {
+        ok(
+          menuItem.hidden,
+          "should only fail to activate when menu item is hidden"
+        );
+        ok(
+          !ShellService.canSetDesktopBackground,
+          "Should only hide when not able to set the desktop background"
+        );
+        is(
+          AppConstants.platform,
+          "linux",
+          "Should always be able to set desktop background on non-linux platforms"
+        );
+        todo(false, "Skipping test on this configuration");
+
+        menu.hidePopup();
+        await menuClosed;
+        return;
+      }
+
+      await menuClosed;
+
+      const win = await dialogLoad;
+
+      /* setDesktopBackground.js does a setTimeout to wait for correct
+       dimensions. If we don't wait here we could read the preview dimensions
+       before they're changed to match the screen */
+      await TestUtils.waitForTick();
+
+      const canvas = win.document.getElementById("screen");
+      const screenRatio = screen.width / screen.height;
+      const previewRatio = canvas.clientWidth / canvas.clientHeight;
+
+      info(`Screen dimensions are ${screen.width}x${screen.height}`);
+      info(`Screen's raw ratio is ${screenRatio}`);
+      info(
+        `Preview dimensions are ${canvas.clientWidth}x${canvas.clientHeight}`
+      );
+      info(`Preview's raw ratio is ${previewRatio}`);
+
+      Assert.ok(
+        previewRatio < screenRatio + 0.01 && previewRatio > screenRatio - 0.01,
+        "Preview's aspect ratio is within ±.01 of screen's"
+      );
+
+      win.close();
+
+      await menuClosed;
+    }
+  );
+});
diff --git a/browser/components/shell/test/head.js b/browser/components/shell/test/head.js
new file mode 100644
index 0000000000..ab7e6d0879
--- /dev/null
+++ b/browser/components/shell/test/head.js
@@ -0,0 +1,159 @@
+"use strict";
+
+const { Subprocess } = ChromeUtils.importESModule(
+  "resource://gre/modules/Subprocess.sys.mjs"
+);
+
+const TEMP_DIR = Services.dirsvc.get("TmpD", Ci.nsIFile).path;
+
+const screenshotPath = PathUtils.join(TEMP_DIR, "headless_test_screenshot.png");
+
+async function runFirefox(args) {
+  const XRE_EXECUTABLE_FILE = "XREExeF";
+  const firefoxExe = Services.dirsvc.get(XRE_EXECUTABLE_FILE, Ci.nsIFile).path;
+  const NS_APP_PREFS_50_FILE = "PrefF";
+  const mochiPrefsFile = Services.dirsvc.get(NS_APP_PREFS_50_FILE, Ci.nsIFile);
+  const mochiPrefsPath = mochiPrefsFile.path;
+  const mochiPrefsName = mochiPrefsFile.leafName;
+  const profilePath = PathUtils.join(
+    TEMP_DIR,
+    "headless_test_screenshot_profile"
+  );
+  const prefsPath = PathUtils.join(profilePath, mochiPrefsName);
+  const firefoxArgs = ["-profile", profilePath, "-no-remote"];
+
+  await IOUtils.makeDirectory(profilePath);
+  await IOUtils.copy(mochiPrefsPath, prefsPath);
+  let proc = await Subprocess.call({
+    command: firefoxExe,
+    arguments: firefoxArgs.concat(args),
+    // Disable leak detection to avoid intermittent failure bug 1331152.
+    environmentAppend: true,
+    environment: {
+      ASAN_OPTIONS:
+        "detect_leaks=0:quarantine_size=50331648:malloc_context_size=5",
+      // Don't enable Marionette.
+      MOZ_MARIONETTE: null,
+    },
+  });
+  let stdout;
+  while ((stdout = await proc.stdout.readString())) {
+    dump(`>>> ${stdout}\n`);
+  }
+  let { exitCode } = await proc.wait();
+  is(exitCode, 0, "Firefox process should exit with code 0");
+  await IOUtils.remove(profilePath, { recursive: true });
+}
+
+async function testFileCreationPositive(args, path) {
+  await runFirefox(args);
+
+  let saved = IOUtils.exists(path);
+  ok(saved, "A screenshot should be saved as " + path);
+  if (!saved) {
+    return;
+  }
+
+  let info = await IOUtils.stat(path);
+  ok(info.size > 0, "Screenshot should not be an empty file");
+  await IOUtils.remove(path);
+}
+
+async function testFileCreationNegative(args, path) {
+  await runFirefox(args);
+
+  let saved = await IOUtils.exists(path);
+  ok(!saved, "A screenshot should not be saved");
+  await IOUtils.remove(path);
+}
+
+async function testWindowSizePositive(width, height) {
+  let size = String(width);
+  if (height) {
+    size += "," + height;
+  }
+
+  await runFirefox([
+    "-url",
+    "http://mochi.test:8888/browser/browser/components/shell/test/headless.html",
+    "-screenshot",
+    screenshotPath,
+    "-window-size",
+    size,
+  ]);
+
+  let saved = await IOUtils.exists(screenshotPath);
+  ok(saved, "A screenshot should be saved in the tmp directory");
+  if (!saved) {
+    return;
+  }
+
+  let data = await IOUtils.read(screenshotPath);
+  await new Promise((resolve, reject) => {
+    let blob = new Blob([data], { type: "image/png" });
+    let reader = new FileReader();
+    reader.onloadend = function() {
+      let screenshot = new Image();
+      screenshot.onload = function() {
+        is(
+          screenshot.width,
+          width,
+          "Screenshot should be " + width + " pixels wide"
+        );
+        if (height) {
+          is(
+            screenshot.height,
+            height,
+            "Screenshot should be " + height + " pixels tall"
+          );
+        }
+        resolve();
+      };
+      screenshot.src = reader.result;
+    };
+    reader.readAsDataURL(blob);
+  });
+  await IOUtils.remove(screenshotPath);
+}
+
+async function testGreen(url, path) {
+  await runFirefox(["-url", url, `--screenshot=${path}`]);
+
+  let saved = await IOUtils.exists(path);
+  ok(saved, "A screenshot should be saved in the tmp directory");
+  if (!saved) {
+    return;
+  }
+
+  let data = await IOUtils.read(path);
+  let image = await new Promise((resolve, reject) => {
+    let blob = new Blob([data], { type: "image/png" });
+    let reader = new FileReader();
+    reader.onloadend = function() {
+      let screenshot = new Image();
+      screenshot.onload = function() {
+        resolve(screenshot);
+      };
+      screenshot.src = reader.result;
+    };
+    reader.readAsDataURL(blob);
+  });
+  let canvas = document.createElement("canvas");
+  canvas.width = image.naturalWidth;
+  canvas.height = image.naturalHeight;
+  let ctx = canvas.getContext("2d");
+  ctx.drawImage(image, 0, 0);
+  let imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);
+  let rgba = imageData.data;
+
+  let found = false;
+  for (let i = 0; i < rgba.length; i += 4) {
+    if (rgba[i] === 0 && rgba[i + 1] === 255 && rgba[i + 2] === 0) {
+      found = true;
+      break;
+    }
+  }
+  ok(found, "There should be a green pixel in the screenshot.");
+
+  await IOUtils.remove(path);
+}
diff --git a/browser/components/shell/test/headless.html b/browser/components/shell/test/headless.html
new file mode 100644
index 0000000000..bbde895077
--- /dev/null
+++ b/browser/components/shell/test/headless.html
@@ -0,0 +1,6 @@
+<html>
+<head><meta content="text/html; charset=utf-8" http-equiv="Content-Type"></head>
+<body style="background-color: rgb(0, 255, 0); color: rgb(0, 0, 255)">
+Hi
+</body>
+</html>
diff --git a/browser/components/shell/test/headless_cross_origin.html b/browser/components/shell/test/headless_cross_origin.html
new file mode 100644
index 0000000000..3bb09aa5d8
--- /dev/null
+++ b/browser/components/shell/test/headless_cross_origin.html
@@ -0,0 +1,7 @@
+<html>
+<head><meta content="text/html; charset=utf-8" http-equiv="Content-Type"></head>
+<body>
+<iframe width="300" height="200" src="http://example.com/browser/browser/components/shell/test/headless_iframe.html"></iframe>
+Hi
+</body>
+</html>
diff --git a/browser/components/shell/test/headless_iframe.html b/browser/components/shell/test/headless_iframe.html
new file mode 100644
index 0000000000..f318cbe0f3
--- /dev/null
+++ b/browser/components/shell/test/headless_iframe.html
@@ -0,0 +1,6 @@
+<html>
+<head><meta content="text/html; charset=utf-8" http-equiv="Content-Type"></head>
+<body style="background-color: rgb(0, 255, 0);">
+Hi
+</body>
+</html>
diff --git a/browser/components/shell/test/headless_redirect.html b/browser/components/shell/test/headless_redirect.html
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/browser/components/shell/test/headless_redirect.html
diff --git a/browser/components/shell/test/headless_redirect.html^headers^ b/browser/components/shell/test/headless_redirect.html^headers^
new file mode 100644
index 0000000000..1d7db20ea5
--- /dev/null
+++ b/browser/components/shell/test/headless_redirect.html^headers^
@@ -0,0 +1,2 @@
+HTTP 302 Moved Temporarily
+Location: headless.html
\ No newline at end of file
diff --git a/browser/components/shell/test/mac_desktop_image.py b/browser/components/shell/test/mac_desktop_image.py
new file mode 100755
index 0000000000..e3ccc77190
--- /dev/null
+++ b/browser/components/shell/test/mac_desktop_image.py
@@ -0,0 +1,168 @@
+#!/usr/bin/python
+# 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/. */
+
+"""
+mac_desktop_image.py
+
+Mac-specific utility to get/set the desktop background image or check that
+the current background image path matches a provided path.
+
+Depends on Objective-C python binding imports which are in the python import
+paths by default when using macOS's /usr/bin/python.
+
+Includes generous amount of logging to aid debugging for use in automated tests.
+"""
+
+import argparse
+import logging
+import os
+import sys
+
+#
+# These Objective-C bindings imports are included in the import path by default
+# for the Mac-bundled python installed in /usr/bin/python. They're needed to
+# call the Objective-C API's to set and retrieve the current desktop background
+# image.
+#
+from AppKit import NSScreen, NSWorkspace
+from Cocoa import NSURL
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Utility to print, set, or "
+        + "check the path to image being used as "
+        + "the desktop background image. By "
+        + "default, prints the path to the "
+        + "current desktop background image."
+    )
+    parser.add_argument(
+        "-v",
+        "--verbose",
+        action="store_true",
+        help="print verbose debugging information",
+        default=False,
+    )
+    group = parser.add_mutually_exclusive_group()
+    group.add_argument(
+        "-s",
+        "--set-background-image",
+        dest="newBackgroundImagePath",
+        required=False,
+        help="path to the new background image to set. A zero "
+        + "exit code indicates no errors occurred.",
+        default=None,
+    )
+    group.add_argument(
+        "-c",
+        "--check-background-image",
+        dest="checkBackgroundImagePath",
+        required=False,
+        help="check if the provided background image path "
+        + "matches the provided path. A zero exit code "
+        + "indicates the paths match.",
+        default=None,
+    )
+    args = parser.parse_args()
+
+    # Using logging for verbose output
+    if args.verbose:
+        logging.basicConfig(level=logging.DEBUG)
+    else:
+        logging.basicConfig(level=logging.CRITICAL)
+    logger = logging.getLogger("desktopImage")
+
+    # Print what we're going to do
+    if args.checkBackgroundImagePath is not None:
+        logger.debug(
+            "checking provided desktop image %s matches current "
+            "image" % args.checkBackgroundImagePath
+        )
+    elif args.newBackgroundImagePath is not None:
+        logger.debug("setting image to %s " % args.newBackgroundImagePath)
+    else:
+        logger.debug("retrieving desktop image path")
+
+    focussedScreen = NSScreen.mainScreen()
+    if not focussedScreen:
+        raise RuntimeError("mainScreen error")
+
+    ws = NSWorkspace.sharedWorkspace()
+    if not ws:
+        raise RuntimeError("sharedWorkspace error")
+
+    # If we're just checking the image path, check it and then return.
+    # A successful exit code (0) indicates the paths match.
+    if args.checkBackgroundImagePath is not None:
+        # Get existing desktop image path and resolve it
+        existingImageURL = getCurrentDesktopImageURL(focussedScreen, ws, logger)
+        existingImagePath = existingImageURL.path()
+        existingImagePathReal = os.path.realpath(existingImagePath)
+        logger.debug("existing desktop image: %s" % existingImagePath)
+        logger.debug("existing desktop image realpath: %s" % existingImagePath)
+
+        # Resolve the path we're going to check
+        checkImagePathReal = os.path.realpath(args.checkBackgroundImagePath)
+        logger.debug("check desktop image: %s" % args.checkBackgroundImagePath)
+        logger.debug("check desktop image realpath: %s" % checkImagePathReal)
+
+        if existingImagePathReal == checkImagePathReal:
+            print("desktop image path matches provided path")
+            return True
+
+        print("desktop image path does NOT match provided path")
+        return False
+
+    # Log the current desktop image
+    if args.verbose:
+        existingImageURL = getCurrentDesktopImageURL(focussedScreen, ws, logger)
+        logger.debug("existing desktop image: %s" % existingImageURL.path())
+
+    # Set the desktop image
+    if args.newBackgroundImagePath is not None:
+        newImagePath = args.newBackgroundImagePath
+        if not os.path.exists(newImagePath):
+            logger.critical("%s does not exist" % newImagePath)
+            return False
+        if not os.access(newImagePath, os.R_OK):
+            logger.critical("%s is not readable" % newImagePath)
+            return False
+
+        logger.debug("new desktop image to set: %s" % newImagePath)
+        newImageURL = NSURL.fileURLWithPath_(newImagePath)
+        logger.debug("new desktop image URL to set: %s" % newImageURL)
+
+        status = False
+        (status, error) = ws.setDesktopImageURL_forScreen_options_error_(
+            newImageURL, focussedScreen, None, None
+        )
+        if not status:
+            raise RuntimeError("setDesktopImageURL error")
+
+    # Print the current desktop image
+    imageURL = getCurrentDesktopImageURL(focussedScreen, ws, logger)
+    imagePath = imageURL.path()
+    imagePathReal = os.path.realpath(imagePath)
+    logger.debug("updated desktop image URL: %s" % imageURL)
+    logger.debug("updated desktop image path: %s" % imagePath)
+    logger.debug("updated desktop image path (resolved): %s" % imagePathReal)
+    print(imagePathReal)
+    return True
+
+
+def getCurrentDesktopImageURL(focussedScreen, workspace, logger):
+    imageURL = workspace.desktopImageURLForScreen_(focussedScreen)
+    if not imageURL:
+        raise RuntimeError("desktopImageURLForScreen returned invalid URL")
+    if not imageURL.isFileURL():
+        logger.warning("desktop image URL is not a file URL")
+    return imageURL
+
+
+if __name__ == "__main__":
+    if not main():
+        sys.exit(1)
+    else:
+        sys.exit(0)
diff --git a/browser/components/shell/test/unit/test_macOS_showSecurityPreferences.js b/browser/components/shell/test/unit/test_macOS_showSecurityPreferences.js
new file mode 100644
index 0000000000..8550f0331a
--- /dev/null
+++ b/browser/components/shell/test/unit/test_macOS_showSecurityPreferences.js
@@ -0,0 +1,30 @@
+/* Any copyright is dedicated to the Public Domain.
+ * https://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Test the macOS ShowSecurityPreferences shell service method.
+ */
+
+function killSystemPreferences() {
+  let killallFile = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsIFile);
+  killallFile.initWithPath("/usr/bin/killall");
+  let sysPrefsArg = ["System Preferences"];
+  let process = Cc["@mozilla.org/process/util;1"].createInstance(Ci.nsIProcess);
+  process.init(killallFile);
+  process.run(true, sysPrefsArg, 1);
+  return process.exitValue;
+}
+
+add_setup(async function() {
+  info("Ensure System Preferences isn't already running");
+  killSystemPreferences();
+});
+
+add_task(async function test_prefsOpen() {
+  let shellSvc = Cc["@mozilla.org/browser/shell-service;1"].getService(
+    Ci.nsIMacShellService
+  );
+  shellSvc.showSecurityPreferences("Privacy_AllFiles");
+
+  equal(killSystemPreferences(), 0, "Ensure System Preferences was started");
+});
diff --git a/browser/components/shell/test/unit/xpcshell.ini b/browser/components/shell/test/unit/xpcshell.ini
new file mode 100644
index 0000000000..383dcb3475
--- /dev/null
+++ b/browser/components/shell/test/unit/xpcshell.ini
@@ -0,0 +1,6 @@
+[DEFAULT]
+skip-if = toolkit == 'android' # bug 1730213
+firefox-appdir = browser
+
+[test_macOS_showSecurityPreferences.js]
+skip-if = toolkit != "cocoa"