See the instructions for how to check out and build Chromium for iOS.
Automated testing is a crucial part of ensuring the quality of Chromium.
Unit testing is done via gtests. To run a unit test, simply run the test target (ending in _unittest).
EarlGrey (EG2) is the integration testing framework used by Chromium for iOS.
EG2 test files are ended with _egtest.mm, and usually located within the same directory of the UI code you wish to test.
Basic imports of a EG2 test file:
#import "ios/chrome/test/earl_grey/chrome_test_case.h"
#import "ios/chrome/test/earl_grey/chrome_earl_grey.h" #import "ios/chrome/test/earl_grey/chrome_earl_grey_ui.h" #import "ios/chrome/test/earl_grey/chrome_matchers.h"
TestCase/testMethods definitions. Create SomeGreatTestCase
as a subclass of ChromeTestCase
. Create test methods, eg -(void)testMyGreatUIFeature {...}
, and put UI actions within the test methods.
+(void)setUpForTestCase
and +tearDown
. These will run once before and after all tests for the test class.-(void)setUp
and -(void)tearDown
. These will run before and after every -(void)testMethod
in the file.Writing test contents. See the chrome helpers (imports in 2.) as well as EarlGrey APIs to write a UI action/assertion in your testMethod.
In EG2 tests, the test process launches the host app process at the beginning, then runs UI actions/assertions in the app. To pass args or feature flags to the app at initial launching, or relaunch the app in the middle of your test, see this AppLaunchManager API.
EG2 test targets are built with test-related code but without app code.
To access anything from the app side, use an “app interface”. App interface is implemented as a class that lives in the app process, but can be accessed in the test process through eDO. You can include the header in your test side code and call class methods of the interface class. The methods will execute code in the app process and can return basic Objective-C types. See this Example of App Interface.
See eg_test_support+eg2
(test side utilities) and eg_app_support+eg2
(app side utilities) targets in BUILD.gn
files to learn how test utilities are organized in targets. If you added an app side helper (app interface), you’ll also need to include your new eg_app_support+eg2
target in //ios/chrome/test/earl_grey/BUILD.gn
’s eg_app_support+eg2
target. (Example CL adding App Interface).
Note that if you create an App interface, you can’t build the app interface class in your eg2_tests target, but you need to include and refer to it. To satisfy the linker, you'll need to create a my_test_app_interface_stub.mm
file with the following content in it and build it as a dependency of your tests that use the app interface.
#import "ios_internal/chrome/test/earl_grey2/my_test_app_interface.h" #import "ios/testing/earl_grey/earl_grey_test.h" GREY_STUB_CLASS_IN_APP_MAIN_QUEUE(MyTestAppInterface)
If you don‘t you’ll get linker errors that read like “Undefined symbols for architecture… MyTestAppInterface”
source_set
) named “eg2_tests” into the closest BUILD.gn
file. Put the test file into the sources
array and put the targets containing headers used in your test file into deps
array. This is to organize test source files and dependencies so that the GN build system can correctly build the test module. The skeleton of the target:source_set("eg2_tests") { configs += [ "//build/config/ios:xctest_config", ] testonly = true sources = [ "some_egtest.mm" ] deps = [ "//ios/chrome/test/earl_grey:eg_test_support+eg2", "//ios/testing/earl_grey:eg_test_support+eg2", ] frameworks = [ "UIKit.framework" ] }
deps
array of a suitable suite in //src/ios/chrome/test/earl_grey2/BUILD.gn
.//src/ios/chrome/test/earl_grey2/BUILD.gn
in the format of existing ones. (Do not forget to config the bots so the new suite can run in infra.)$ gn gen --check out/Debug-iphonesimulator
EarlGrey tests are based on Apple's XCUITest.
gclient runhooks
to sync for the list of tests in Xcode.--extra-app-args
, e.g. --extra-app-args='--enable-features=Foo'
.EG2 tests can run in the command line with test runner scripts. You’ll need to build the targets before running tests in cmd. This is used by continuous integration infra and thus not user friendly. Running UI tests directly in Xcode is recommended.
Important notes:
Example:
src/ios/build/bots/scripts/run.py --app src/out/Debug-iphonesimulator/ios_chrome_ui_eg2tests_module-Runner.app --host-app src/out/Debug-iphonesimulator/ios_chrome_eg2tests.app --args-json {"test_args": [], "xctest": false, "test_cases": ["ReadingListTestCase"], "restart": false, "xcode_parallelization": true, "xcodebuild_device_runner": false} --out-dir path/to/output/dir --retries 3 --shards 1 --xcode-build-version 11c29 --mac-toolchain-cmd path/to/mac_toolchain --xcode-path path/to/Xcode.app --wpr-tools-path NO_PATH --replay-path NO_PATH --iossim src/out/Debug-iphonesimulator/iossim --platform iPad (6th generation) --version 13.3
The invocation args are logged. You can find the latest arg format at the beginning of stdout from an infra test shard if the above doesn't work.