CTS Development

In this document

Initializing your Repo client

Follow the instructions to get and build the Android source code but specify a particular CTS branch name, for example-b android-5.0_r2, when issuing the repo init command. This assures your CTS changes will be included in the next CTS release and beyond.

Building and running CTS

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

Note: You may supply one of these other values for TARGET_PRODUCT to build for different architectures: aosp_x86_64 or aosp_mips

cd /path/to/android/root
make cts -j32 TARGET_PRODUCT=aosp_arm64

At the cts-tf console, enter e.g.:

run cts --plan CTS

Writing CTS tests

CTS tests use JUnit and the Android testing APIs. Review the Testing and Instrumentation tutorial while perusing the existing tests under the cts/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 sample 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.

Fix or remove tests

Besides adding new tests there are other ways to contribute to CTS: Fix or remove tests annotated with "BrokenTest" or "KnownFailure."

Submitting your changes

Follow the Submitting Patches workflow to contribute changes to CTS. A reviewer will be assigned to your change, and your change should be reviewed shortly!

Release schedule and branch information

CTS releases follow this schedule.

Note: This schedule is tentative and may be updated from time to time as CTS for the given Android version matures.

Version Branch Frequency
7.0 nougat-cts-dev Monthly
6.0 marshmallow-cts-dev Monthly
5.1 lollipop-mr1-cts-dev Monthly
5.0 lollipop-cts-dev No releases planned
4.4 kitkat-cts-dev No releases planned
4.3 jb-mr2-cts-dev No releases planned
4.2 jb-mr1.1-cts-dev No releases planned

Important Dates during month of the release

  • End of 1st Week: Code Freeze. At this point, submissions on the current branch will no longer be accepted and will not be included in the next version of CTS. Once we have chosen a candidate for release, the branch will again be open and accepting new submissions.
  • Second or third week: CTS is published in the Android Open Source Project (AOSP).

Auto-merge flow

CTS development branches have been set up so that changes submitted to each branch will automatically merge as below:
jb-dev-> jb-mr1.1-cts-dev -> jb-mr2-cts-dev -> kitkat-cts-dev -> lollipop-cts-dev -> lollipop-mr1-cts-dev -> marshmallow-cts-dev -> nougat-cts-dev -> <private-development-branch for Android N MR1>

If a changelist (CL) fails to merge correctly, the author of the CL will get an email with instructions on how to resolve the conflict. In most of the cases, the author of the CL can use the instructions to skip the auto-merge of the conflicting CL.