README.md

This package is similar to [source_gen_test], but it allows you to compare the output of a generator with a golden Dart file.

Usage

part 'goldens/testclass.dart';

@ShouldGenerateFile(
  'goldens/testclass.dart',
  partOfCurrent: true,
  configurations: ['default', 'no-prefix-required'],
)
@TestAnnotation()
class TestClass {}

Rationale

For an example use, see this package: https://github.com/alexeyinkin/dart-enum-map/tree/main/enum_map_gen

The package generates code of 160+ lines. To verify such a long output, it is useful to not only test that the output matches a string, but also to write tests on that output itself.

This file uses the ShouldGenerateFile annotation: https://github.com/alexeyinkin/dart-enum-map/blob/main/enum_map_gen/test/unmodifiable_enum_map/src/input.dart

This is the golden that the output is compared with: https://github.com/alexeyinkin/dart-enum-map/blob/main/enum_map_gen/test/unmodifiable_enum_map/src/output.dart

This is the test on that golden: https://github.com/alexeyinkin/dart-enum-map/blob/main/enum_map_gen/test/unmodifiable_enum_map/unmodifiable_enum_map_test.dart

This pair of tests ensures that the output both matches the desired one and works as expected.

Status

This does not have to be a separate package. There is a PR to source_gen_test itself that adds this annotation.

Unfortunately, it is not yet merged, but the need for this feature was pushing, so this separate package was published. It was copied from source_gen_test, then ShouldGenerate and ShouldThrow were deleted. So were all the tests that were failing because of the deletion.

This approach is inconvenient, because:

• There is a lot of code duplication.
• Using both packages together is hard.

There was no chance for a more elegant way, because source_gen_test is closed for extension.

I expect to deprecate this package when the above PR is merged.

The version of this package matches the version of source_gen_test it was synchronized with.