expectRebuildBudgetIsTestOnly function

void expectRebuildBudgetIsTestOnly({ String? packageRoot, })

Fails the test if the app lists rebuildcop under dependencies or imports it from lib/.

It reads the app's pubspec.yaml and every .dart file under lib/, and the failure names the file and line of each finding:

rebuildcop must stay out of the app in /work/shop: it depends
on flutter_test, and every dependency and every import from lib/ is
compiled into release builds.
  pubspec.yaml:14: rebuildcop is under dependencies, ...
  lib/debug_menu.dart:3: imports package:rebuildcop/...

dev_dependencies (from pub.dev, a path or git) and dependency_overrides are fine, and so are imports from test/, integration_test/ or anywhere else outside lib/. Comments that mention the package are not imports. In a pub workspace, put this test in each package that depends on rebuildcop.

The app is the package around the running test file: the nearest directory above it with a pubspec.yaml. Pass packageRoot to check a different package directory; that throws a StateError if it has no pubspec.yaml. It needs a file system, so it throws an UnsupportedError under flutter test --platform chrome.

Implementation

void expectRebuildBudgetIsTestOnly({String? packageRoot}) {
  final root = packageRoot ?? findPackageRoot(_testFileDirectory());
  if (root == null) {
    fail('No pubspec.yaml above ${_testFileDirectory()}; pass packageRoot.');
  }
  final findings = checkPackage(root);
  if (findings.isNotEmpty) fail(describeFindings(root, findings));
}