Each package may include a configuration file that applies to the package as a whole. This file can be used to provide custom defaults for various options, to define configuration for multiple files, and more.

The file is named dart_test.yaml and lives at the root of the package, next to the package‘s pubspec. Like the pubspec, it’s a YAML file. Here's an example:

# This package's tests are very slow. Double the default timeout.
timeout: 2x

# This is a browser-only package, so test on content shell by default.
platforms: [content-shell]

Config Fields

These fields directly affect the behavior of the test runner. They go at the root of the configuration file.

paths

This field indicates the default paths that the test runner should run. These paths are usually directories, although single filenames may be used as well. Paths must be relative, and they must be in URL format so that they're compatible across operating systems. This defaults to [test].

paths: [dart/test]

paths:
- test/instantaneous
- test/fast
- test/middling

filename

This field indicates the filename pattern that the test runner uses to find test files in directories. All files in directories passed on the command line (or in directories in paths, if none are passed) whose basenames match this pattern will be loaded and run as tests.

This supports the full glob syntax. However, since it‘s only compared against a path’s basename, path separators aren't especially useful. It defaults to "*_test.dart".

filename: "test_*.dart"

platforms

This field indicates which platforms tests should run on by default. It allows the same platform identifiers that can be passed to --platform. If multiple platforms are included, the test runner will default to running tests on all of them. This defaults to [vm].

platforms: [content_shell]

platforms:
- chrome
- firefox

concurrency

This field indicates the default number of test suites to run in parallel. More parallelism can improve the overall speed of running tests up to a point, but eventually it just adds more memory overhead without any performance gain. This defaults to approximately half the number of processors on the current machine. If it's set to 1, only one test suite will run at a time.

concurrency: 3

pub_serve

This field indicates that the test runner should run against a pub serve instance by default, and provides the port number for that instance. Note that if there is no pub serve instance running at that port, running the tests will fail by default.

pub_serve: 8081

timeout

This field indicates how much time the test runner should allow a test to remain inactive before it considers that test to have failed. It has three possible formats:

  • The string “none” indicates that tests should never time out.

  • A number followed by a unit abbreviation indicates an exact time. For example, “1m” means a timeout of one minute, and “30s” means a timeout of thirty seconds. Multiple numbers can be combined, as in “1m 30s”.

  • A number followed by “x” indicates a multiple. This is applied to the default value of 30s.

timeout: 1m

reporter

This field indicates the default reporter to use. It may be set to “compact”, “expanded”, or “json” (although why anyone would want to default to JSON is beyond me). It defaults to “expanded” on Windows and “compact” everywhere else.

reporter: expanded

verbose_trace

This boolean field controls whether or not stack traces caused by errors are trimmed to remove internal stack frames. This includes frames from the Dart core libraries, the stack_trace package, and the test package itself. It defaults to false.

verbose_trace: true

js_trace

This boolean field controls whether or not stack traces caused by errors that occur while running Dart compiled to JS are converted back to Dart style. This conversion uses the source map generated by dart2js to approximate the original Dart line, column, and in some cases member name for each stack frame. It defaults to false.

js_trace: true