CTS development

Initialize your Repo client

Follow the instructions from Downloading the Source to get and build the Android source code. When issuing the repo init command, specify a specific CTS branch using -b. This ensures that your CTS changes are included in subsequent CTS releases.

The following example code shows how to use repo init.

Build and run CTS

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

Build CTS (AOSP 14 or earlier)

cd /path/to/android/root
source build/envsetup.sh
make cts -j32 TARGET_PRODUCT=aosp_arm64
cts-tradefed

Build CTS (AOSP 15 or later)

cd /path/to/android/root
source build/envsetup.sh
make cts -j32 TARGET_PRODUCT=aosp_arm64 TARGET_RELEASE=target-release
cts-tradefed

Please refer to the following table to select the target-release value:

In the CTS console, enter:

tf> run cts --plan CTS

Write CTS tests

CTS tests use JUnit and the Android testing APIs. Review the Test your app tutorial and existing tests under the cts/tests directory. CTS tests mostly follow the same conventions used in other Android tests.

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

• Take into account varying screen sizes, orientations, and keyboard layouts.
• Use only public API methods. In other words, avoid all classes, methods, and fields with the hide annotation.
• Avoid using view layouts or relying on the dimensions of assets that may not be on some devices.
• Don't rely on root privileges.

Add Java annotation

If your test verifies an API behavior, annotate your test code with @ApiTest and list all APIs involved in the apis field. Use the appropriate format from among the following examples:

If your test verifies a CDD requirement, annotate the requirement ID (including CDD Section ID and Requirement ID) with @CddTest in the CTS test code as shown in the following example. In your commit message, mention which CDD requirement is tested by your test by referring to CDD requirement IDs. CDD requirement IDs are a combination of section ID and requirement ID, connected by a slash (/) as in 7.3.1/C-1-1.

/**
* Verify Passpoint configuration management APIs for a Passpoint
* @throws Exception
*/
    @CddTest(requirement="7.4.2.3/C-1-1,C-2-1")
    public void testAddPasspointConfigWithUserCredential() throws Exception {
        if (!WifiFeature.isWifiSupported(getContext())) {
            // skip the test if WiFi is not supported
            return;
        }      testAddPasspointConfig(generatePasspointConfig(generateUserCredential()));
    }

For CTS Verifier, annotate each Activity in your AndroidManifest.xml with the relevant CDD ID. The formats for value fields are similar to formats of Java annotations in CTS. In the commit message, mention which CDD requirement is enforced by referencing the CDD requirement ID.

  <activity>
    ......
    <!-- OPTIONAL: Add a meta data attribute to indicate CDD requirements. -->
    <meta-data android:name="cdd_test" android:value="7.4.1/C-4-1" />

    <!-- OPTIONAL: Add a meta data attribute to indicate APIs being tested. -->
    <meta-data android:name="api_test"
               android:value="com.example.MyClass#myMethod" />

    <!-- OPTIONAL: Add a metadata attribute to indicate the reason why the test doesn't enforce any CDD requirement but still useful in CTS-V. -->
    <meta-data android:name="non_compliance_test"
               android:value="detailed reasons" />
  </activity>

In the commit message

Clearly mention why your test needs to be added, and add relevant links for support. For CTS-D tests, include a link to the test proposal that you created in Google Issue Tracker as part of the CTS-D submission process.

Create a subplan

As an example, you can add a SubPlan.xml file in android-cts/subplans as follows:

<?xml version="1.0" encoding="utf-8" standalone="no"?>
<SubPlan version="2.0">
<Entry include="CtsSystemIntentTestCases" />
<Entry include="CtsSystemUiHostTestCases" />
<Entry include="CtsSecurityHostTestCases android.security.cts.SELinuxHostTest#testAospFileContexts" />
<Entry include="CtsSecurityHostTestCases android.security.cts.SELinuxHostTest#testAospServiceContexts" />
</SubPlan>

To run the subplan:

run cts --subplan aSubPlan

The subplan entry format is:

Include a module name as follows:
<Entry include="MODULE_NAME" />

Include a package:
<Entry include="MODULE_NAME PACKAGE_NAME" />

Include a class:
<Entry include="MODULE_NAME PACKAGE_NAME.CLASS_NAME" />

Include an individual test:
<Entry include="MODULE_NAME PACKAGE_NAME.CLASS_NAME#TEST_NAME" />

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 a Test suffix. Each test case consists of multiple tests, where each test typically exercises a specific method of the class being tested. These tests are arranged in a directory structure where tests are grouped into different categories such as "widgets" or "views".

For example, the CTS test for the Java package android.widget.TextView is android.widget.cts.TextViewTest with its Java package name as android.widget.cts and its class name as TextViewTest.

• Java package name
  The Java package name for the CTS tests is the package name of the class that the test is testing, followed by .cts. For our example, the package name would be android.widget.cts.
• Class name
  The class name for CTS tests is the name of the class being tested with "Test" appended. For example, if a test is targeting TextView, the class name should be TextViewTest.
• Module name (CTS v2 only)
  CTS v2 organizes tests by module. The module name is usually the second string of the Java package name (in our example, widget).

The directory structure and sample code depend on whether you are using CTS v1 or CTS v2.

CTS v1

For Android 6.0 or lower, use CTS v1. For CTS v1, the sample code is at cts/tests/tests/example.

The directory structure in CTS v1 tests looks like this:

cts/
  tests/
    tests/
      package-name/
        Android.mk
        AndroidManifest.xml
        src/
          android/
            package-name/
              SampleDeviceActivity.java
              cts/
                SampleDeviceTest.java

CTS v2

For Android 7.0 or higher, use CTS v2. For details, see the sample test in Android Open Source Project (AOSP).

The CTS v2 directory structure looks like this:

cts/
  tests/
    module-name/
      Android.mk
      AndroidManifest.xml
      src/
        android/
          package-name/
            SampleDeviceActivity.java
            cts/
              SampleDeviceTest.java

New sample packages

When adding new tests, there might not be an existing directory to place your test. In those cases, you need to create the directory and copy the appropriate sample files.

CTS v1

If you're using CTS v1, refer to the example under cts/tests/tests/example and create a new directory. Also, make sure to add your new package's module name from its Android.mk to CTS_COVERAGE_TEST_CASE_LIST in cts/CtsTestCaseList.mk. build/core/tasks/cts.mk uses this makefile to combine all the tests and create the final CTS package.

CTS v2

Use the sample test /cts/tests/sample/ to quick start your new test module with the following steps:

1. To create the test directory and copy sample files, run:

   mkdir cts/tests/module-name && cp -r cts/tests/sample/* cts/tests/module-name

2. Navigate to cts/tests/module-name and substitute all instances of "[Ss]ample" with the recommended naming convention from above.
3. Update SampleDeviceActivity to exercise the feature you're testing.
4. Update SampleDeviceTest to ensure that the activity succeeds or logs its errors.

Additional directories

Other Android directories such as assets, jni, libs, and res can also be added. To add JNI code, create a directory in the root of the project next to src with the native code and an Android.mk makefile in it.

The makefile typically contains the following settings:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := libCtsSample_jni

# don't include this package in any target
LOCAL_MODULE_TAGS := optional
LOCAL_SRC_FILES := list of source code files
LOCAL_C_INCLUDES := $(JNI_H_INCLUDE)

# Tag this module as a cts test artifact
LOCAL_COMPATIBILITY_SUITE := cts
LOCAL_SHARED_LIBRARIES := libnativehelper
LOCAL_SDK_VERSION := current
include $(BUILD_SHARED_LIBRARY)

Android.mk file

Finally, modify the Android.mk file in the root of the project to build the native code and depend on it, as shown below:

# All tests should include android.test.runner.
LOCAL_JAVA_LIBRARIES := android.test.runner

# Includes the jni code as a shared library
LOCAL_JNI_SHARED_LIBRARIES := libCtsSample_jni

# Include for InstrumentationCtsTestRunner
LOCAL_STATIC_JAVA_LIBRARIES := ctstestrunner...
LOCAL_SDK_VERSION := currentinclude $(BUILD_CTS_PACKAGE)

#Tells make to look in subdirectories for more make files to include
include $(call all-makefiles-under,$(LOCAL_PATH))

Fix or remove tests

In addition to adding new tests, you can fix or remove tests annotated with BrokenTest or KnownFailure.

Submit your changes

When submitting CTS or VTS patches in AOSP, choose your development branch based on which API levels the patch applies to.

• For changes that apply to multiple API levels, first develop a patch in aosp/main and then cherry-pick to the most upstream test branch. Allow the automerger to merge the changes downstream in AOSP test branches. See Release schedule and branch information for the list of branches and automerge path information.
• For changes that are specific to a specific API level, develop or cherry-pick the changes to the correct test branch with DO NOT MERGE or RESTRICT AUTOMERGE in the commit message.

Follow the Submitting patches workflow to contribute changes to CTS. A reviewer will be assigned to review your change accordingly.

Release schedule and branch information

CTS releases follow this schedule.

Important dates during the release

• End of the first week: Code freeze. Changes merged in the branch until the code freeze are considered for the upcoming version of CTS. Submissions to the branch after the code freeze, or after a candidate for release is chosen, are considered for the subsequent release.
• Second or third week: CTS is published in AOSP.

Automerge flow

CTS development branches have been set up so that changes submitted to each branch automatically merge to higher branches.

For changes directly to an AOSP test dev branch, the automerge path is:
android11-tests-dev > android12-tests-dev > android12L-tests-dev > android13-tests-dev > android14-tests-dev > android15-tests-dev > aosp-main

For changes only to the next Android version, the automerge path is:
aosp-main > <Internal git_main>.

If a changelist (CL) fails to merge correctly, the author of the patch is sent an email with instructions on how to resolve the conflict. In most of the cases, the author of the patch can use the instructions to skip the automerge of the conflicting CL.

If an older branch requires the change, then the patch needs to be cherry-picked from the newer branch.