| // Copyright 2013 The Flutter Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| import 'dart:io'; |
| |
| import 'package:image/image.dart'; |
| import 'package:path/path.dart' as p; |
| import 'package:skia_gold_client/skia_gold_client.dart'; |
| |
| import 'environment.dart'; |
| import 'goldens.dart'; |
| |
| /// Compares a screenshot taken through a test with its golden. |
| /// |
| /// Used by Flutter Web Engine unit tests and the integration tests. |
| /// |
| /// Returns the results of the tests as `String`. When tests passes the result |
| /// is simply `OK`, however when they fail it contains a detailed explanation |
| /// on which files are compared, their absolute locations and an HTML page |
| /// that the developer can see the comparison. |
| Future<String> compareImage( |
| Image screenshot, |
| bool doUpdateScreenshotGoldens, |
| String filename, |
| PixelComparison pixelComparison, |
| double maxDiffRateFailure, |
| SkiaGoldClient? skiaClient, { |
| required bool isCanvaskitTest, |
| }) async { |
| if (skiaClient == null) { |
| return 'OK'; |
| } |
| |
| final String screenshotPath = _getFullScreenshotPath(filename); |
| final File screenshotFile = File(screenshotPath); |
| await screenshotFile.create(recursive: true); |
| await screenshotFile.writeAsBytes(encodePng(screenshot), flush: true); |
| |
| if (isLuciEnv) { |
| // This is temporary to get started by uploading existing screenshots to |
| // Skia Gold. The next step would be to actually use Skia Gold for |
| // comparison. |
| final int screenshotSize = screenshot.width * screenshot.height; |
| |
| late int pixelColorDelta; |
| if (isCanvaskitTest) { |
| pixelColorDelta = 21; |
| } else if (skiaClient.dimensions != null && skiaClient.dimensions!['Browser'] == 'ios-safari') { |
| pixelColorDelta = 15; |
| } else { |
| pixelColorDelta = 3; |
| } |
| skiaClient.addImg( |
| filename, |
| screenshotFile, |
| screenshotSize: screenshotSize, |
| pixelColorDelta: pixelColorDelta, |
| ); |
| return 'OK'; |
| } |
| |
| final Image? golden = await _getGolden(filename); |
| |
| if (doUpdateScreenshotGoldens) { |
| return 'OK'; |
| } |
| |
| if (golden == null) { |
| // This is a new screenshot that doesn't have an existing golden. |
| |
| // At the moment, we don't support local screenshot testing because we use |
| // Skia Gold to handle our screenshots and diffing. In the future, we might |
| // implement local screenshot testing if there's a need. |
| print('Screenshot generated: file://$screenshotPath'); // ignore: avoid_print |
| return 'OK'; |
| } |
| |
| // Compare screenshots. |
| final ImageDiff diff = ImageDiff( |
| golden: golden, |
| other: screenshot, |
| pixelComparison: pixelComparison, |
| ); |
| |
| if (diff.rate > 0) { |
| final String testResultsPath = environment.webUiTestResultsDirectory.path; |
| Directory(testResultsPath).createSync(recursive: true); |
| final String basename = p.basenameWithoutExtension(filename); |
| |
| final File actualFile = |
| File(p.join(testResultsPath, '$basename.actual.png')); |
| actualFile.writeAsBytesSync(encodePng(screenshot), flush: true); |
| |
| final File diffFile = File(p.join(testResultsPath, '$basename.diff.png')); |
| diffFile.writeAsBytesSync(encodePng(diff.diff), flush: true); |
| |
| final File expectedFile = |
| File(p.join(testResultsPath, '$basename.expected.png')); |
| screenshotFile.copySync(expectedFile.path); |
| |
| final File reportFile = |
| File(p.join(testResultsPath, '$basename.report.html')); |
| reportFile.writeAsStringSync(''' |
| Golden file $filename did not match the image generated by the test. |
| |
| <table> |
| <tr> |
| <th>Expected</th> |
| <th>Diff</th> |
| <th>Actual</th> |
| </tr> |
| <tr> |
| <td> |
| <img src="$basename.expected.png"> |
| </td> |
| <td> |
| <img src="$basename.diff.png"> |
| </td> |
| <td> |
| <img src="$basename.actual.png"> |
| </td> |
| </tr> |
| </table> |
| '''); |
| |
| final StringBuffer message = StringBuffer(); |
| message.writeln( |
| 'Golden file $filename did not match the image generated by the test.'); |
| message.writeln(getPrintableDiffFilesInfo(diff.rate, maxDiffRateFailure)); |
| message.writeln('You can view the test report in your browser by opening:'); |
| |
| final String localReportPath = '$testResultsPath/$basename.report.html'; |
| message.writeln(localReportPath); |
| message.writeln('Golden file: ${expectedFile.path}'); |
| message.writeln('Actual file: ${actualFile.path}'); |
| |
| if (diff.rate < maxDiffRateFailure) { |
| // Issue a warning but do not fail the test. |
| print('WARNING:'); // ignore: avoid_print |
| print(message); // ignore: avoid_print |
| return 'OK'; |
| } else { |
| // Fail test |
| return '$message'; |
| } |
| } |
| return 'OK'; |
| } |
| |
| Future<Image?> _getGolden(String filename) { |
| // TODO(mdebbar): Fetch the golden from Skia Gold. |
| return Future<Image?>.value(); |
| } |
| |
| String _getFullScreenshotPath(String filename) { |
| return p.join(environment.webUiSkiaGoldDirectory.path, filename); |
| } |