address some comments

Author: nturgut

e2etests/web/regular_integration_tests/lib/screenshot_support.dart

@@ -16,7 +16,7 @@ import 'package:image/image.dart';
 ///
 /// We are allowing a higher difference rate compared to the unit tests (where
 /// this rate is set to 0.28), since during the end to end tests there are
-/// more components on the screen which are not related to the functinality
+/// more components on the screen which are not related to the functionality
 /// under test ex: a blinking cursor.
 const double kMaxDiffRateFailure = 0.5 / 100; // 0.5%
 
@@ -31,29 +31,26 @@ const double kMaxDiffRateFailure = 0.5 / 100; // 0.5%
 ///
 /// It provides an `onScreenshot` callback to the `integrationDriver` method.
 /// It also includes options for updating the golden files.
-Future<void> main() async {
+Future<void> runTestWithScreenshots(
+    {double diffRateFailure = kMaxDiffRateFailure}) async {
   final WebFlutterDriver driver =
       await FlutterDriver.connect() as WebFlutterDriver;
 
   // Learn the browser in use from the webDriver.
   final String browser = driver.webDriver.capabilities['browserName'] as String;
 
   bool updateGoldens = false;
-  try {
+  final String updateGoldensFlag = io.Platform.environment['UPDATE_GOLDENS'];
+  if (updateGoldensFlag == null || updateGoldensFlag.toLowerCase() != 'true') {
     // We are using an environment variable since instead of an argument, since
     // this code is not invoked from the shell but from the `flutter drive`
     // tool itself. Therefore we do not have control on the command line
     // arguments.
     // Please read the README, further info on how to update the goldens.
-    updateGoldens =
-        io.Platform.environment['UPDATE_GOLDENS'].toLowerCase() == 'true';
-  } catch (ex) {
-    if (ex
-        .toString()
-        .contains('is not a subtype of type \'bool\' in type cast')) {
-      print('INFO: goldens will not be updated, please set `UPDATE_GOLDENS` '
-          'environment variable to true');
-    }
+    print('INFO: Goldens will not be updated. Please set `UPDATE_GOLDENS` '
+        'environment variable to `true` for updating them.');
+  } else {
+    updateGoldens = true;
   }
 
   test.integrationDriver(
@@ -65,7 +62,7 @@ Future<void> main() async {
         updateGoldens,
         '$screenshotName-$browser.png',
         PixelComparison.fuzzy,
-        kMaxDiffRateFailure,
+        diffRateFailure,
         forIntegrationTests: true,
         write: updateGoldens,
       );

e2etests/web/regular_integration_tests/test_driver/text_editing_integration_test.dart

@@ -2,9 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:regular_integration_tests/screenshot_support.dart'
-    as with_screenshot;
+import 'package:regular_integration_tests/screenshot_support.dart' as test;
 
 Future<void> main() async {
-  await with_screenshot.main();
+  await test.runTestWithScreenshots();
 }

web_sdk/common_test_utils/lib/exceptions.dart

@@ -2,10 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:io' as io;
-
-import 'package:meta/meta.dart';
-
 class BrowserInstallerException implements Exception {
   BrowserInstallerException(this.message);
 

web_sdk/golden_comparator/lib/goldens.dart

@@ -191,7 +191,7 @@ String getPrintableDiffFilesInfo(double diffRate, double maxRate) =>
     '(${((diffRate) * 100).toStringAsFixed(4)}% of pixels were different. '
     'Maximum allowed rate is: ${(maxRate * 100).toStringAsFixed(4)}%).';
 
-/// Downloads the repository that we store the golden files.
+/// Downloads the repository that stores the golden files.
 ///
 /// Reads the url of the repo and `commit no` to sync to, from
 /// `goldens_lock.yaml`.
@@ -257,7 +257,7 @@ class GoldensRepoFetcher {
   }
 
   /// Runs `git` with given arguments.
-  Future<int> _runGit(
+  Future<void> _runGit(
     List<String> arguments,
     String workingDirectory,
   ) async {
@@ -276,6 +276,5 @@ class GoldensRepoFetcher {
           'workingDirectory: $workingDirectory resulting with exitCode: '
           '$exitCode');
     }
-    return exitCode;
   }
 }