Testing in Android

Building on Testing, we will now look at how unit tests work in AOSP. Use the rust_test module for your unit tests:

testing/Android.bp:

javascript

{{#include testing/Android.bp}}

testing/src/lib.rs:

rust

# // Copyright 2024 Google LLC
# // SPDX-License-Identifier: Apache-2.0
#
{{#include testing/src/lib.rs:leftpad}}

You can now run the test with

shell

{{#include build_all.sh:libleftpad_test}}

The output looks like this:

text

INFO: Elapsed time: 2.666s, Critical Path: 2.40s
INFO: 3 processes: 2 internal, 1 linux-sandbox.
INFO: Build completed successfully, 3 total actions
//comprehensive-rust-android/testing:libleftpad_test_host            PASSED in 2.3s
    PASSED  libleftpad_test.tests::long_string (0.0s)
    PASSED  libleftpad_test.tests::short_string (0.0s)
Test cases: finished with 2 passing and 0 failing out of 2 test cases

Notice how you only mention the root of the library crate. Tests are found recursively in nested modules.