webGoldenComparator top-level property Null safety
Compares pixels against those of a golden image file.
This comparator is used as the backend for matchesGoldenFile when tests are running in a web browser.
When using flutter test --platform=chrome, a comparator implemented by
DefaultWebGoldenComparator is used if no other comparator is specified. It
will send a request to the test server, which uses goldenFileComparator
for golden file comparison.
When using flutter test --update-goldens, the DefaultWebGoldenComparator
updates the files on disk to match the rendering.
When using flutter run, the default comparator
(_TrivialWebGoldenComparator) is used. It prints a message to the console
but otherwise does nothing. This allows tests to be developed visually on a
web browser.
Callers may choose to override the default comparator by setting this to a custom comparator during test set-up (or using directory-level test configuration). For example, some projects may wish to install a comparator with tolerance levels for allowable differences.
See also:
- flutter_test for more information about how to configure tests at the directory-level.
- goldenFileComparator, the comparator used when tests are not running on a web browser.
Implementation
WebGoldenComparator get webGoldenComparator => _webGoldenComparator;Implementation
set webGoldenComparator(WebGoldenComparator value) {
_webGoldenComparator = value;
}