flutter/dev/devicelab/README.md

Flutter devicelab

This package contains the test framework and tests that run on physical devices. More generally the tests are referred to as "tasks" in the API, but since we primarily use it for testing, this document refers to them as "tests".

Writing tests

A test is a simple Dart program that lives under bin/tests and uses package:flutter_devicelab/framework/framework.dart to define and run a task.

Example:

import 'dart:async';

import 'package:flutter_devicelab/framework/framework.dart';

Future<Null> main() async {
  await task(() async {
    ... do something interesting ...

    // Aggregate results into a JSONable Map structure.
    Map<String, dynamic> testResults = ...;

    // Report success.
    return new TaskResult.success(testResults);

    // Or you can also report a failure.
    return new TaskResult.failure('Something went wrong!');
  });
}

Only one task is permitted per program. However, that task can run any number of tests internally. A task has a name. It succeeds and fails independently of other tasks, and is reported to the dashboard independently of other tasks.

A task runs in its own standalone Dart VM and reports results via Dart VM service protocol. This ensures that tasks do not interfere with each other and lets the CI system time out and clean up tasks that get stuck.

Adding tests to the CI environment

The manifest.yaml file describes a subset of tests we run in the CI. To add your test edit manifest.yaml and add the following in the "tasks" dictionary:

  {NAME_OF_TEST}:
    description: {DESCRIPTION}
    stage: {STAGE}
    required_agent_capabilities: {CAPABILITIES}

Where:

• {NAME_OF_TEST} is the name of your test that also matches the name of the file in bin/tests without the .dart extension.
• {DESCRIPTION} is the plain English description of your test that helps others understand what this test is testing.
• {STAGE} is devicelab if you want to run on Android, or devicelab_ios if you want to run on iOS.
• {CAPABILITIES} is an array that lists the capabilities required of the test agent (the computer that runs the test) to run your test. Available capabilities are: has-android-device, has-ios-device.

Running tests locally

Do make sure your tests pass locally before deploying to the CI environment. Below is a handful of commands that run tests in a fashion very close to how the CI environment runs them. These commands are also useful when you need to reproduce a CI test failure locally.

To run a test use option -t (--task):

dart bin/run.dart -t {NAME_OF_TEST}

To run multiple tests repeat option -t (--task) multiple times:

dart bin/run.dart -t test1 -t test2 -t test3

To run all tests defined in manifest.yaml use option -a (--all):

dart bin/run.dart -a

To run tests from a specific stage use option -s (--stage):

dart bin/run.dart -s {NAME_OF_STAGE}