fix: very_good dart test --coverage fails in pub workspaces

[marcossevilla]

Description

Running very_good dart test with coverage collection enabled (via --coverage, or implicitly via --min-coverage/--show-uncovered, or via the new 1.4.0 very_good.yaml dart.test.min_coverage config) crashes with a PathNotFoundException when run from inside a member package of a Dart pub workspace.

Pub workspaces resolve dependencies once at the workspace root, so .dart_tool/package_config.json is only generated at the root, not duplicated inside each member package's own .dart_tool/. The very_good dart test coverage step looks for that file relative to the current working directory instead of resolving it the way dart pub/dart test themselves do (walking up to the workspace root), so it fails whenever it's invoked from inside a member directory.

Steps To Reproduce

1. Create a pub workspace:

   # pubspec.yaml (root)
   name: workspace_root
   environment:
     sdk: ^3.9.0
   workspace:
     - packages/foo

2. Create a member package packages/foo with resolution: workspace in its pubspec.yaml, and a trivial passing test.
3. From the workspace root, run dart pub get.
4. cd packages/foo
5. Run very_good dart test --coverage
6. See error:

   Running "dart test" in . ...
   ✓ Optimizing tests (90ms)
   00:01 +60: All tests passed!
   PathNotFoundException: Cannot open file, path = '.dart_tool/package_config.json' (OS Error: No such file or directory, errno = 2)
   

   Exit code 69.

Expected Behavior

Tests run and a coverage report is produced, the same as running dart test --coverage directly (which works fine in this exact layout).

Additional Context

• Setting dart.test.min_coverage in very_good.yaml implicitly turns on coverage collection (collectCoverage: options.collectCoverage || options.minCoverage != null || options.showUncovered), so a bare very_good dart test with no flags at all starts crashing the moment that config key is added, with no indication that pub workspaces are the cause.
• very_good test (the Flutter-oriented command, which delegates to flutter test) does not hit this issue in the same workspace/directory — its coverage-collection path resolves the package config differently and more tolerantly of the workspace layout.
• Confirmed the workspace only materializes package_config.json at the root (workspace_root/.dart_tool/package_config.json), never inside packages/foo/.dart_tool/, even after re-running dart pub get from inside the member directory.

Possible fix

lib/src/cli/test_cli_runner.dart, inside TestCLIRunner.test(), in the block that post-processes coverage for dart test:

if (testType == TestRunType.dart && collectCoverage) {
  final files = _dartCoverageFilesToProcess(p.join(cwd, 'coverage'));

  final packagesPath = p.join('.dart_tool', 'package_config.json');
  final hitmap = await coverage.HitMap.parseFiles(
    files,
    packagePath: packagesPath,
    checkIgnoredLines: checkIgnore,
  );

  final resolver = await coverage.Resolver.create(
    packagesPath: packagesPath,
    packagePath: packagesPath,
  );
  ...

Every other path in this function joins against cwd (e.g. p.join(cwd, 'coverage', 'lcov.info') a few lines above). This one is a bare literal resolved relative to whatever directory the process happens to be in, which never resolves in a pub workspace since .dart_tool/package_config.json only exists at the workspace root.

Two ways to fix it, in order of correctness:

1. Join against cwd: p.join(cwd, '.dart_tool', 'package_config.json'). Fixes non-workspace recursive runs against nested directories, but still doesn't fix workspaces.
2. Walk up from cwd looking for .dart_tool/package_config.json, the same way VeryGoodConfig.load() already walks up looking for very_good.yaml in lib/src/very_good_config/very_good_config.dart. That walk-up logic could be extracted and reused here.

Environment

• very_good_cli: 1.4.0
• Dart SDK: 3.12.2 (stable)
• Flutter: 3.44.2
• OS: macOS 15 (Darwin 25.5.0), arm64

[AzazelSensei]

Opened #1689 for this. Coverage now resolves package_config by walking up from the package directory, same as dart.