To make Chromium tests work properly in the Brave codebase, you may need to modify either the test logic or the production logic. This document explains the available mechanisms in the check_is_test.h and chrome_test_suite.cc files to accomplish this.

The CurrentTestVendor::Get() function allows you to determine the currently running test vendor. It is set to kBrave for brave_* test binaries and kChromium for Chromium test binaries. This can be used to conditionally alter production logic during tests.

#include "base/check_is_test.h"

void SomeFunction() {
  if (base::CurrentTestVendor::Get() == base::TestVendor::kChromium) {
    // Alter logic for Chromium tests.
  } else {
    // Default Brave logic.
  }
}

The BraveChromeTestSetupHelper class in //brave/chromium_src/chrome/test/base/chrome_test_suite.cc allows you to customize test behavior by enabling or disabling features based on test patterns.

Note: This approach should only be used for Chromium tests to avoid unnecessary patching of the upstream source files.

The BraveChromeTestSetupHelper class uses a list of TestAdjustments to specify which features to enable or disable for specific test patterns.

class BraveChromeTestSetupHelper : public testing::EmptyTestEventListener {
  void OnTestStart(const testing::TestInfo& test_info) override {
    static const base::NoDestructor<std::vector<TestAdjustments>> kTestAdjustments({
        {
            .test_patterns = {"SomeTestPattern.*"},
            .enable_features = {"SomeFeature"},
            .disable_features = {"AnotherFeature"},
        },
    });
    // ...
  }
};