WebView Test Instructions

Android Instructions

Please follow the instructions at android_test_instructions.md. This guide is an extension with WebView-specific content.

Note: except where otherwise noted, all tests require a device or emulator.

Chromium-side tests

Instrumentation tests

These tests live under //android_webview/javatests/, and are mostly end-to-end (with the exception of the //android_webview/glue/ layer).

# Build
$ autoninja -C out/Default webview_instrumentation_test_apk

# Run tests (any of these commands):
$ out/Default/bin/run_webview_instrumentation_test_apk # All tests
$ out/Default/bin/run_webview_instrumentation_test_apk -f AwContentsTest#* # A particular test suite
$ out/Default/bin/run_webview_instrumentation_test_apk -f AwContentsTest#testClearCacheInQuickSuccession # A single test
$ out/Default/bin/run_webview_instrumentation_test_apk -f AwContentsTest#*Succession # Any glob pattern matching 1 or more tests

Native unittests

These are any *_test.cc or *_unittest.cc test under //android_webview/. Currently, we only have tests under //android_webview/browser/ and //android_webview/lib/.

# Build
$ autoninja -C out/Default android_webview_unittests

# Run tests (any of these commands):
$ out/Default/bin/run_android_webview_unittests # All tests
$ out/Default/bin/run_android_webview_unittests -f AndroidStreamReaderURLRequestJobTest.* # Same glob patterns work here

Useful test runner options

Debugging flaky tests

$ out/Default/bin/run_webview_instrumentation_test_apk \ # Any test runner
    --num_retries=0 \ # Tests normally retry-on-failure; disable for easier repo
    --repeat=1000 \ # Repeat up to 1000 times for a failure
    --break-on-failure \ # Stop repeating once we see the first failure
    -f=AwContentsTest#testClearCacheInQuickSuccession

Enable a Feature for a local run

$ out/Default/bin/run_webview_instrumentation_test_apk \ # Any test runner
    # Desired Features; see commandline-flags.md for more information
    --enable-features="NetworkService,NetworkServiceInProcess" \
    -f=AwContentsTest#testClearCacheInQuickSuccession

External tests

As WebView is an Android system component, we have some tests defined outside of the chromium repository, but which the team still maintains. For some of these tests, we have scripts to help chromium developers check these tests.

All of these tests are end-to-end, so they exercise whatever WebView implementation you've installed and selected on your device. This also means you can enable Features and commandline flags the same way as you would for production.

CTS

WebView has CTS tests, testing end-to-end behavior. These tests live in the Android source tree (under //platform/cts/tests/tests/webkit/).

Chromium developers can run these tests with:

$ android_webview/tools/run_cts.py \
    --arch=arm64 \ # Choose your device arch
    --platform=M \ # CTS test suite version; must be <= device SDK level
    --apk-dir="$HOME/run-cts-apk-dir" \ # Any folder, it's just a cache
    --verbose \ # Optional
    -f=android.webkit.cts.WebViewTest#* # Supports similar test filters

If you'd like to edit these tests, see internal documentation at http://go/clank-webview for working with Android checkouts.

AndroidX (Support Library)

WebView also has an AndroidX module, which has its own tests (similar to CTS tests). These tests live under the AOSP source tree, under //platform/frameworks/support/.

TODO(ntfschr): document the solution for http://crbug.com/891102, when that's fixed.