Feature Request: An `xcodeproj_test` rule to test configured `xcodeproj` running the installer and then executing select `xcodebuild` actions against the generated Xcode project

Start with the xcodeproj_test usage described in the issue and the examples/ios_app configuration. Trace how the xcodeproj target is installed, then determine how the default runner should invoke xcodebuild for the selected scheme and build_actions. Done means the generated project and scheme can be exercised, with support for a custom runner as described.

Goals

• Provide assurances to rules_xcodeproj contributors that changes to the underlying rules work.
• Allow clients of rules_xcodeproj to test the schemes for configured projects.
  • Execute a build command for a scheme.
  • Execute a test command for a scheme.

Design/Usage

• Provide xcodeproj_test that handles the test setup and Xcode project installation.
• Provide a default test runner that executes xcodebuild commands against the Xcode project.
• Allow clients to provide their own test runner.

Details

The idea is that we want to exercise the generated project/scheme. The following example is based upon examples/ios_app.

XCODEPROJ_TARGETS = [
    "//Example",
    "//ExampleTests",
    "//ExampleObjcTests",
    "//ExampleUITests",
]

XCODEPROJ_SCHEMES = [
    xcode_schemes.scheme(
        name = "ios_app",
        launch_action = xcode_schemes.launch_action("//Example"),
        test_action = xcode_schemes.test_action(
            "//ExampleTests",
            "//ExampleObjcTests",
            "//ExampleUITests",
        ),
    ),
]

xcodeproj(
    name = "xcodeproj",
    project_name = "iOS App",
    tags = ["manual"],
    top_level_targets = XCODEPROJ_TARGETS,
    schemes = XCODEPROJ_SCHEMES,
)

We want to be sure that the generated project and scheme work properly.

# This test will run the installer for `:xcodeproj`, then run the following:
#   xcodebuild -project iOS\ App.xcodeproj -scheme ios_app \
#      -sdk iphonesimulator \
#      -destination 'platform=iOS Simulator,name=iPhone 12,OS=14.3' \
#      test archive
# If the the command succeeds, the test passes. If the command does not, the test fails.
xcodeproj_test(
    name = "ios_app_scheme_test",
    xcodeproj = ":xcodeproj",
    scheme = "ios_app",
    # The `xcodebuild -help` lists these as `buildaction`. The interesting ones are `build`, 
    # `archive`, and `test`.
    build_actions = ["test", "archive"],
)

Alternative Design

You may want to separate the test from the runner. The test would take a reference to an xcodeproj target. It would prepare the test and run the installer. The runner would execute the xcodebuild command. The benefit would be that other runners could be used instead of an xcodebuild runner.