src/compatibility/cts-development.md

<!--
   Copyright 2010 The Android Open Source Project 

   Licensed under the Apache License, Version 2.0 (the "License"); 
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
-->

# CTS Development #

## Initializing Your Repo Client ##

Follow the [instructions](/source/downloading.html)
to get and build the Android source code but specify `-b android-4.0.3_r1`
when issuing the `repo init` command. This assures that your CTS
changes will be included in the next CTS release and beyond.

## Setting Up Eclipse ##

Follow the [instructions](/source/using-eclipse.html)
to setup Eclipse but execute the following command to generate the
`.classpath` file rather than copying the one from the development
project:

    cd /path/to/android/root
    ./cts/development/ide/eclipse/genclasspath.sh > .classpath
    chmod u+w .classpath

This `.classpath` file will contain both the Android framework
packages and the CTS packages.

## Building and Running CTS ##

Execute the following commands to build CTS and start the interactive
CTS console:

    cd /path/to/android/root
    make cts
    cts

Provide arguments to CTS to immediately start executing a test:

    cts start --plan CTS -p android.os.cts.BuildVersionTest

## Writing CTS Tests ##

CTS tests use JUnit and the Android testing APIs. Review the 
[Testing and Instrumentation](https://developer.android.com/guide/topics/testing/testing_android.html)
tutorial while perusing the existing tests under the
`cts/tests/tests` directory. You will see that CTS tests mostly follow the same
conventions used in other Android tests.

Since CTS runs across many production devices, the tests must follow
these rules:

- Must take into account varying screen sizes, orientations, and keyboard layouts.
- Only use public API methods. In other words, avoid all classes, methods, and fields that are annotated with the "hide" annotation.
- Avoid relying upon particular view layouts or depend on the dimensions of assets that may not be on some device.
- Don't rely upon root privileges.

### Test Naming and Location ###

Most CTS test cases target a specific class in the Android API. These tests
have Java package names with a `cts` suffix and class
names with the `Test` suffix. Each test case consists of
multiple tests, where each test usually exercises a particular API method of
the API class being tested. These tests are arranged in a directory structure
where tests are grouped into different categories like "widgets" and "views."

For example, the CTS test for `android.widget.TextView` is
`android.widget.cts.TextViewTest` found under the
`cts/tests/tests/widget/src/android/widget/cts` directory with its
Java package name as `android.widget.cts` and its class name as
`TextViewTest`. The `TextViewTest` class has a test called `testSetText`
that exercises the "setText" method and a test named "testSetSingleLine" that
calls the `setSingleLine` method. Each of those tests have `@TestTargetNew`
annotations indicating what they cover.

Some CTS tests do not directly correspond to an API class but are placed in
the most related package possible. For instance, the CTS test,
`android.net.cts.ListeningPortsTest`, is in the `android.net.cts`, because it
is network related even though there is no `android.net.ListeningPorts` class.
You can also create a new test package if necessary. For example, there is an
"android.security" test package for tests related to security. Thus, use your
best judgement when adding new tests and refer to other tests as examples.

Finally, a lot of tests are annotated with @TestTargets and @TestTargetNew.
These are no longer necessary so do not annotate new tests with these.

### New Test Packages ###

When adding new tests, there may not be an existing directory to place your
test. In that case, refer to the example under `cts/tests/tests/example` and
create a new directory. Furthermore, make sure to add your new package's
module name from its `Android.mk` to `CTS_COVERAGE_TEST_CASE_LIST` in
`cts/CtsTestCaseList.mk`. This Makefile is used by `build/core/tasks/cts.mk`
to glue all the tests together to create the final CTS package.

### Test Stubs and Utilities ###

Some tests use additional infrastructure like separate activities
and various utilities to perform tests. These are located under the
`cts/tests/src` directory. These stubs aren't separated into separate test
APKs like the tests, so the `cts/tests/src` directory does not have additional
top level directories like "widget" or "view." Follow the same principle of
putting new classes into a package with a name that correlates to the purpose
of your new class. For instance, a stub activity used for testing OpenGL like
`GLSurfaceViewStubActivity` belongs in the `android.opengl.cts` package under
the `cts/tests/src/android/opengl` directory.

## Other Tasks ##

Besides adding new tests there are other ways to contribute to CTS:

- Fix or remove tests annotated with BrokenTest and KnownFailure.

## Submitting Your Changes ##

Follow the [Android Contributors' Workflow](/source/submit-patches.html)
to contribute changes to CTS. A reviewer
will be assigned to your change, and your change should be reviewed shortly!