package:source_gen/source_gen can no-longer be imported inside Flutter codebases

[rrousselGit]

It appears that the main source_gen/source_gen.dart import can no-longer be used within flutter test

We can no-longer do:

// test/my_test.dart

import 'package:source_gen/source_gen.dart';
void main() {}

flutter test test/my_test.dart

Some of my codebases have the testsuite of generators depend on both Generator-related stuff and Flutter, so that tests can use resolveFiles and analyze Flutter code.

[davidmorgan]

Could you please point to a specific example? I'll see if I can figure out a way to make it work.

The dependency change is probably from build.

[rrousselGit]

// asset:example/lib/example.dart

class Generator extends SharedPartBuilder {
 ...
}

// asset:example/test/example_source.dart
import 'package:flutter/widgets.dart';

class Example extends StatelessWidget {
  @override
  Widget build(context) => Container();
}

// asset:example/test/example_test.dart
import 'package:analyzer/analyzer.dart';
import 'package:example/example.dart';

void main() {
  test('example', () async {
    final unit = resolveFiles2('path to exampe_source');

    Generator().generateForElement(unit.libraryElement2.classes.first);
  });
}

Hand typed, so expect some typos. This is just a rough example.

Riverpod's codebase does that, often to test error cases or specifics of the parsing logic that can break easily

[davidmorgan]

build is not so well separated as it used it be, the refactor introduced some cross dependencies; I still need to figure out how to clean up. dart-lang/build#4068

Is the problem because of dart:mirrors? We need to remove mirrors use anyway, to compile AOT. Now would be a good time :)

[rrousselGit]

dart:mirrors, yes. Flutter doesn't have it. Although I'm not sure if other imports could be problematic too.

[davidmorgan]

@rrousselGit I tried isolating the dart:mirrors import as much as possible, any chance you could give it a try and see if it solves the problem?

dart-lang/build#4111

dependency_overrides:
  build_runner:
    git:
      url: https://github.com/dart-lang/build
      path: build_runner
      ref: 8355dd011de981e60ad0c333ea7c10beb024b07e
  build_runner_core:
    git:
      url: https://github.com/dart-lang/build
      path: build_runner_core
      ref: 8355dd011de981e60ad0c333ea7c10beb024b07e

I will also look at removing mirrors use but that will take a little longer.

[rrousselGit]

I've managed to migrate my codebase without those dependency overrides. Not sure what the original issue was then. I'll close this since I can't reproduce anymore.

[davidmorgan]

Good to know, thanks.

Then, I'll skip this quick fix--but I'll still be working on getting rid of mirrors properly, so we can compile AOT. dart-lang/build#3836