Welcome! package:test is the standard testing library for Dart and Flutter. If you have questions about Dart testing, please see the docs for package:test. package:test_api and package:test_core are implementation details and generally not user-facing.

package:checks is a relatively new library for expressing test expectations. It's a more modern version of package:matcher and features a literate API.

Package	Description	Issues	Version
checks	A framework for checking values against expectations and building custom expectations.
fake_async	Fake asynchronous events such as timers and microtasks for deterministic testing.
matcher	Support for specifying test expectations via an extensible Matcher class. Also includes a number of built-in Matcher implementations for common cases.
test	A full featured library for writing and running Dart tests across platforms.
test_api	The user facing API for structuring Dart tests and checking expectations.
test_core	A basic library for writing tests and running them on the VM.
test_descriptor	An API for defining and verifying files and directory structures.
test_process	Test processes: starting; validating stdout and stderr; checking exit code.