tester

Use via dart pub global activate tester

An experimental test runner, designed for fast incremental test processing workflows and maximum flexibility due to a lack of significant runtime. Currently supports running tests on the Dart VM & Flutter, and within the Chrome browser it can run both Dart Web and Flutter for Web tests. Requires a version of the Flutter SDK that is extremely close to ToT to be present on the PATH, or configured via FLUTTER_ROOT.

setup

tester is distributed via pub, and can be installed with dart pub global activate tester.

Running tests

tester should be run from the project root, the directory containing pubspec.yaml. By default, it will run all files in test/ ending in _test.dart once and exit. It also accepts multiple positional arguments for one or more individual test files.

tester test/a_test.dart test/b_test.dart

The tester can also be started in a resident process that re-runs when test files or library sources are changed.

tester --watch

Writing Tests

tester uses top-level declarations (beginning with "test") to declare test cases, with dartdoc providing additional context. It cannot use the expect function from package:test, but a similar declaration is available in package:expect.

import 'package:expect/expect.dart';

void testFoo() {
  // asserts are fine too
  assert(foo() == true);
}

/// Here is a comment that will show up in test logs if it fails.
void testLists() {
  var xs = doThing();
  expect(xs, [1, 2, 3]);
}

tester may also be run in package:test compatibility mode, which is automatically detected if your package depends on package:test. This allows tester to execute normal tests, to allow a gradual migration or mixed codebase.

Test Concurrency

tester runs each test in serial. In batch mode, multiple runners can be configured using --concurrency/-j. Increasing this number above 1 (the default) will slow down startup times, but may be faster for large numbers of tests.

tester -j4

Test Platforms

The test platform (Dart VM, Flutter, Web, Flutter Web) can be configured using --platform. Web platforms require a chrome executable to be available.

tester --platform=dart test/dart_test.dart
tester --platform=flutter test/flutter_test.dart

Coverage

Code coverage can be measured by passing --coverage (batch-mode only for now). This is currently only supported on dart and flutter platforms, and not web or flutter_web.