fix: Improve the output of many matchers that expect specific types

- Add a package-private FeatureMatcher class to generalize type checking
- Use it across many of the existing Matcher implementations
- Update tests validate new, more consistent failure messages
- Add a few new tests for `isIn`
13 files changed
tree: 04243340416036adc64e79eab7b2c0f5c423a96f
  1. .gitignore
  2. .test_config
  3. .travis.yml
  7. analysis_options.yaml
  8. codereview.settings
  9. lib/
  10. pubspec.yaml
  11. test/

Support for specifying test expectations, such as for unit tests.

The matcher library provides a third-generation assertion mechanism, drawing inspiration from Hamcrest.

For more information, see Unit Testing with Dart.