fix: check-unused-files now ignored some system files (#671)

* fix: `check-unused-files` now ignored some system files

* chore: code review fixes

* chore: revert

Author: dkrutskikh

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 * feat: add new command flag `--no-congratulate`.
 * feat: add `--version` flag to print current version of the package.
+* feat: improve `check-unused-files` and `check-unused-code` commands, add support for flutter internal entry functions.
 * fix: make `check-unused-l10n` also cover supertype member calls.
 * fix: cyclomatic complexity calculation for functions with internal lambdas.
 * chore: restrict `analyzer` version to `>=2.4.0 <3.3.0`.

lib/src/utils/node_utils.dart

@@ -37,7 +37,11 @@ SourceSpan nodeLocation({
 }
 
 bool isEntrypoint(String name, NodeList<Annotation> metadata) =>
-    name == 'main' || _hasPragmaAnnotation(metadata);
+    name == 'main' ||
+    _hasPragmaAnnotation(metadata) ||
+    _flutterInternalEntryFunctions.contains(name);
+
+const _flutterInternalEntryFunctions = {'registerPlugins', 'testExecutable'};
 
 /// See https://github.com/dart-lang/sdk/blob/master/runtime/docs/compiler/aot/entry_point_pragma.md
 bool _hasPragmaAnnotation(Iterable<Annotation> metadata) =>