8. Run on-device tests#

Host tests are the best way to test hardware-independent logic in your codebase because they are much easier to scale. Eventually, however, you need to tests parts of your codebase that interact with hardware. Sometimes you can mock or stub the hardware logic and still run the tests host-side. Other times you really do need to run the tests on-device. Pigweed provides robust and automated solutions for running hardware-in-the-loop tests.

Note

This step requires the full hardware setup and must be run over a terminal.

Note

This section requires the VS Code terminal because there’s currently no way to run wildcard tests from the Bazel Targets UI. Wildcard tests will be explained more in a moment.

Set up your hardware#

  1. Set up your hardware to match the full setup. On-device tests only work with the full setup. You can skip ahead to 9. Communicate with your Pico over RPC if you don’t have the full setup hardware.

Run on-device tests#

  1. Open a terminal:

    1. Open the Command Palette.

    2. Run the Pigweed: Set Bazelisk Path command and then select Use the version built in to the Pigweed extension option.

    3. Open the Command Palette again and run the Pigweed: Activate Bazelisk In Terminal command.

      You should see a terminal open like this:

      export PATH="/home/kayce/.vscode/extensions/pigweed.pigweed-1.3.3/node_modules/@bazel/bazelisk:${PATH}"
kayce@kayce0:~/tmp/sense$ export PATH="/home/kayce/.vscode/extensions/pigweed.pigweed-1.3.3/node_modules/@bazel/bazelisk:${PATH}"
kayce@kayce0:~/tmp/sense$

    Just follow your normal workflow for opening a terminal window or tab.

  2. Start a test runner.

    bazelisk run \
    @pigweed//targets/rp2040/py:unit_test_server \
    -- --debug-probe-only --chip RP2040

    bazelisk run \
    @pigweed//targets/rp2040/py:unit_test_server \
    -- --debug-probe-only --chip RP2350

    You should see output like this:

    INFO: Analyzed target @@pigweed~//targets/rp2040/py:unit_test_server (134 packages loaded, 13872 targets configured).
INFO: Found 1 target...
Target @@pigweed~//targets/rp2040/py:unit_test_server up-to-date:
  bazel-bin/external/pigweed~/targets/rp2040/py/unit_test_server
INFO: Elapsed time: 32.497s, Critical Path: 18.71s
INFO: 177 processes: 12 internal, 165 linux-sandbox.
INFO: Build completed successfully, 177 total actions
INFO: Running command line: bazel-bin/external/pigweed~/targets/rp2040/py/unit_test_server <args omitted>
20240806 18:22:29 OUT [370633] 2024/08/06 18:22:29 Parsed server configuration from /tmp/tmparhr7i8o
20240806 18:22:29 OUT [370633] 2024/08/06 18:22:29 Registered ExecDeviceRunner /home/kayce/.cache/bazel/_bazel_kayce/12747149b267f61f52f2c26162a31942/execroot/_main/bazel-out/k8-fastbuild/bin/external/pigweed~/targets/rp2040/py/rpc_unit_test_runner with args [--usb-bus 3 --usb-port 6]
20240806 18:22:29 OUT [370633] 2024/08/06 18:22:29 Starting gRPC server on [::]:34172
20240806 18:22:29 OUT [370633] [ServerWorkerPool] 2024/08/06 18:22:29 Starting 1 workers
20240806 18:22:29 OUT [370633] [ExecDeviceRunner 0] 2024/08/06 18:22:29 Starting worker

    The test runner essentially orchestrates how all the unit tests should be run.

    Leave this server running and proceed to the next step.

  3. Open another terminal tab and run the tests.

    bazelisk test --config=rp2040 //...

    bazelisk test --config=rp2350 //...

    # ...
INFO: Found 134 targets and 10 test targets...
INFO: Elapsed time: 131.231s, Critical Path: 60.93s
INFO: 2368 processes: 423 internal, 1945 linux-sandbox.
INFO: Build completed successfully, 2368 total actions
//modules/pubsub:service_test                                  SKIPPED
//modules/air_sensor:air_sensor_test                           PASSED in 30.2s
//modules/blinky:blinky_test                                   PASSED in 14.3s
//modules/buttons:manager_test                                 PASSED in 41.0s
//modules/edge_detector:hysteresis_edge_detector_test          PASSED in 7.3s
//modules/lerp:lerp_test                                       PASSED in 26.0s
//modules/morse_code:encoder_test                              PASSED in 35.6s
//modules/pubsub:pubsub_events_test                            PASSED in 18.2s
//modules/pubsub:pubsub_test                                   PASSED in 22.1s
//modules/state_manager:state_manager_test                     PASSED in 38.5s

Executed 9 out of 10 tests: 9 tests pass and 1 was skipped.

    Note

    The //... in this command is what makes this a wildcard test. //... means “run all tests defined thoughout the project”. The --config option specifies what hardware the tests will run on.

  4. Go to the terminal that the test runner is running in and press Control+C to close it.

Flash the blinky app onto your Pico again#

You’re done with the on-device tests. Flash the blinky app back onto your Pico again:

In Bazel Targets expand //apps/blinky, then right-click :flash_rp2040 (native binary), then select Run target.

In Bazel Targets expand //apps/blinky, then right-click :flash_rp2350 (native binary), then select Run target.

bazelisk run //apps/blinky:flash_rp2040

bazelisk run //apps/blinky:flash_rp2350

Summary#

Host tests are a great way to verify that hardware-agnostic application logic is correct. For any logic that’s intimately connected to hardware, however, on-device tests are necessary. Pigweed provides robust support for extensive automation of hardware-in-the-loop tests.

Next, head over to 9. Communicate with your Pico over RPC to explore how to communicate with your Pico from your host.

On this page