// Copyright 2026 The Chromium Authors // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #import #import "base/functional/bind.h" #import "ios/chrome/browser/metrics/model/metrics_app_interface.h" #import "ios/chrome/browser/shared/public/features/features.h" #import "ios/chrome/test/earl_grey/chrome_earl_grey.h" #import "ios/chrome/test/earl_grey/chrome_test_case.h" #import "ios/testing/earl_grey/earl_grey_test.h" #import "net/test/embedded_test_server/embedded_test_server.h" #import "net/test/embedded_test_server/http_request.h" #import "net/test/embedded_test_server/http_response.h" using chrome_test_util::GREYAssertErrorNil; namespace { const char kPlainPath[] = "/plain"; const char kMetaPath[] = "/meta"; const char kCssPath[] = "/css"; const char kMediaPath[] = "/media"; std::unique_ptr HandleRequest( const net::test_server::HttpRequest& request) { std::unique_ptr response = std::make_unique(); response->set_code(net::HTTP_OK); response->set_content_type("text/html"); if (request.relative_url == kPlainPath) { response->set_content("

Plain

"); } else if (request.relative_url == kMetaPath) { response->set_content( "" "

CSS Property

"); } else if (request.relative_url == kMediaPath) { response->set_content( "

Media Query

"); } else { return nullptr; } return std::move(response); } } // namespace @interface DarkModeDetectionTestCase : ChromeTestCase @end @implementation DarkModeDetectionTestCase - (AppLaunchConfiguration)appConfigurationForTestCase { AppLaunchConfiguration config; config.features_enabled.push_back(kIOSDarkModeDetection); return config; } - (void)setUp { [super setUp]; self.testServer->RegisterRequestHandler(base::BindRepeating(&HandleRequest)); GREYAssertTrue(self.testServer->Start(), @"EmbeddedTestServer failed to start."); NSError* error = [MetricsAppInterface setupHistogramTester]; GREYAssertErrorNil(error, @"Failed to setup histogram tester"); } - (void)tearDownHelper { NSError* error = [MetricsAppInterface releaseHistogramTester]; GREYAssertErrorNil(error, @"Failed to release histogram tester"); [super tearDownHelper]; } // Helper to assert histogram states. - (void)assertHistogramSupportWithMeta:(BOOL)meta css:(BOOL)css mediaQuery:(BOOL)mediaQuery overall:(BOOL)overall { // Since page loads are async, we wait until the general dark mode support // metric is recorded GREYCondition* condition = [GREYCondition conditionWithName:@"Waiting for DarkModeDetection UMA metric" block:^BOOL { NSError* error = [MetricsAppInterface expectTotalCount:1 forHistogram: @"IOS.DarkModeDetection.SupportsDarkMode"]; return error == nil; }]; GREYAssert([condition waitWithTimeout:5], @"Failed to record SupportsDarkMode UMA metric."); UIUserInterfaceStyle user_interface_style = UITraitCollection.currentTraitCollection.userInterfaceStyle; BOOL is_dark = (user_interface_style == UIUserInterfaceStyleDark); int supported_bucket = is_dark ? 3 : 2; int not_supported_bucket = is_dark ? 1 : 0; NSError* error = nil; error = [MetricsAppInterface expectUniqueSampleWithCount:1 forBucket:meta ? supported_bucket : not_supported_bucket forHistogram:@"IOS.DarkModeDetection.SupportsViaMeta"]; GREYAssertErrorNil(error, @"SupportsViaMeta assertion failed"); error = [MetricsAppInterface expectUniqueSampleWithCount:1 forBucket:css ? supported_bucket : not_supported_bucket forHistogram:@"IOS.DarkModeDetection.SupportsViaCss"]; GREYAssertErrorNil(error, @"SupportsViaCss assertion failed"); error = [MetricsAppInterface expectUniqueSampleWithCount:1 forBucket:mediaQuery ? supported_bucket : not_supported_bucket forHistogram: @"IOS.DarkModeDetection.SupportsViaMediaQuery"]; GREYAssertErrorNil(error, @"SupportsViaMediaQuery assertion failed"); error = [MetricsAppInterface expectUniqueSampleWithCount:1 forBucket:overall ? supported_bucket : not_supported_bucket forHistogram:@"IOS.DarkModeDetection.SupportsDarkMode"]; GREYAssertErrorNil(error, @"SupportsDarkMode assertion failed"); } // Tests that loading a plain page reports no dark mode support. - (void)testPlainPageReportsNoSupport { [ChromeEarlGrey loadURL:self.testServer->GetURL(kPlainPath)]; [self assertHistogramSupportWithMeta:NO css:NO mediaQuery:NO overall:NO]; } // Tests that loading a meta-configured page reports meta support. - (void)testMetaDarkPageReportsMetaSupport { [ChromeEarlGrey loadURL:self.testServer->GetURL(kMetaPath)]; [self assertHistogramSupportWithMeta:YES css:NO mediaQuery:NO overall:YES]; } // Tests that loading a CSS-property-configured page reports CSS support. - (void)testCssStyleDarkPageReportsCssSupport { [ChromeEarlGrey loadURL:self.testServer->GetURL(kCssPath)]; [self assertHistogramSupportWithMeta:NO css:YES mediaQuery:NO overall:YES]; } // Tests that loading a media-query-configured page reports media-query support. - (void)testMediaStyleDarkPageReportsMediaQuerySupport { [ChromeEarlGrey loadURL:self.testServer->GetURL(kMediaPath)]; [self assertHistogramSupportWithMeta:NO css:NO mediaQuery:YES overall:YES]; } @end