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.
- Just write a unit test if the purpose of your test does not involve UI.
- Learn about EarlGrey test framework principles and APIs in EarlGrey.
- Learn about Defining Test Cases and Test Methods from Apple.
-
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:
- You’ll have to include:
#import "ios/chrome/test/earl_grey/chrome_test_case.h"
- You’ll most likely find util functions in these files helpful.
#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"
- Beside these, directly import an EG2 header for an EG2 API you are using.
-
TestCase/testMethods definitions. Create
SomeGreatTestCase
as a subclass ofChromeTestCase
. Create test methods, eg-(void)testMyGreatUIFeature {...}
, and put UI actions within the test methods.- Put your setup and tear down code for the TestCase in
+(void)setUpForTestCase
and+tearDown
. These will run once before and after all tests for the test class. - Put your setup and tear down code for each test method in
-(void)setUp
and-(void)tearDown
. These will run before and after every-(void)testMethod
in the file.
- Put your setup and tear down code for the TestCase in
-
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 <TestLib/EarlGreyImpl/EarlGrey.h>
#if !defined(__has_feature) || !__has_feature(objc_arc)
#error "This file requires ARC support."
#endif
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”
- Create a test target. Add a target(
source_set
) named "eg2_tests" into the closestBUILD.gn
file. Put the test file into thesources
array and put the targets containing headers used in your test file intodeps
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/compiler:enable_arc",
"//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",
"//ios/third_party/earl_grey2:test_lib",
]
frameworks = [ "UIKit.framework" ]
}
- Include your test target in the
deps
array of a suitable suite in//src/ios/chrome/test/earl_grey2/BUILD.gn
. - Optional: If you feel like your new test should be in a new suite, or you
want to delete an existing suite to make tests better organized, you’ll need to
change the suites in
//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.) - Ensure your dependencies are correct.
$ gn gen --check out/Debug-iphonesimulator
EarlGrey tests are based on Apple's XCUITest.
- If you added a new test file / suite, run
gclient runhooks
to sync for the list of tests in Xcode. - Change the scheme to "ios_chrome_eg2test". Create and select the simulator you wish to use.
- You may run a test suite(module), TestCase or testMethod in test navigator. Xcode will build the targets and run the test(s) you choose. Alternatively, use ⌘+U to run all the tests. See Apple's Running Tests and Viewing Results.
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:
- The test runner can invoke mac_toolchain to install a new Xcode of the version specified to the path specified. You may want to choose a different path from your daily use Xcode.
- If test_cases is empty in --args-json, all tests will run. Specifying a testMethod to run is currently not supported in the test runner.
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.