android_webview/docs/contributing-tests.md

# Contributing to WebView Tests

[TOC]

## Instrumentation tests
These are on-device integration tests for android\_webview with rest of the
chromium code (covering both Java and native code). A large percentage of
Android applications use WebView, and could trigger WebView specific code paths
in the codebase, therefore it is important to have solid integration tests.

#### Where to add tests?
The tests are located in the [javatests directory](/android_webview/javatests/src/org/chromium/android_webview/test/).
They are roughly organized by the
[Aw classes](/android_webview/java/src/org/chromium/android_webview/) (some
tests are organized by overall functionality instead). Put new tests into an
existing test class or create a new one if a suitable one isn't available.

#### How to write intrumentation tests?
See the [instrumentation test doc](/testing/android/docs/instrumentation.md).

#### How do tests interact with WebView?
Tests are written as JUnit4 tests. [AwActivityTestRule] is used to create and
obtain references to WebView objects such as [AwContents](internally it launches
the [WebView instrumentation shell](/android_webview/test/shell/src/org/chromium/android_webview/shell/)
application to hold [AwTestContainerViews](/android_webview/test/shell/src/org/chromium/android_webview/test/AwTestContainerView.java)
which in turn contains [AwContents]). [AwContents] will allow the test to
trigger code paths such as loading urls, going forwards/backwards, etc... .
[AwActivityTestRule] has some helper methods to call the [AwContents] methods,
for example to ensure that they are called on the UI thread. Some AW
components, such as [AwCookieManager](/android_webview/java/src/org/chromium/android_webview/AwCookieManager.java),
can be directly created in tests.

#### How do tests inject html/css/js content?
Tests can use the load\* methods in [AwActivityTestRule] to inject snippets
of content. This will however bypass the network layer. To have end-to-end
testing, use [EmbeddedTestServer](/net/test/android/javatests/src/org/chromium/net/test/EmbeddedTestServer.java),
which will allow simple loading of files from the [data directory](/android_webview/test/data/).
For loading data from arbitrary URIs and more advanced control, the
[TestWebServer](/net/test/android/javatests/src/org/chromium/net/test/util/TestWebServer.java)
can be used.

## Java unittest (JUnit)
These are off-device tests using robolectric that only exercise android\_webview
Java code.

#### Where do add tests?
The tests are located in the [junit directory](/android_webview/junit/src/org/chromium/android_webview/robolectric/).

#### How to write junit tests?
See the [JUnit doc](/testing/android/docs/junit.md#junit-tests-with-robolectric).

## Native unittests
These are on-device gtests that only exercise android\_webview native code.

#### Where to add tests?
The tests are located alongside respective source code files under
[android\_webview directory](/android_webview/).

#### How to write gtests?
See the [GTest doc](/testing/android/docs/gtest_implementation.md).

## How to run tests?
Running tests is covered in [WebView Test Instructions](/android_webview/docs/test-instructions.md).

[AwActivityTestRule]:
/android_webview/javatests/src/org/chromium/android_webview/test/AwActivityTestRule.java
[AwContents]:
/android_webview/java/src/org/chromium/android_webview/AwContents.java