fix: test optimizer to import files as valid dart names

bricks/test_optimizer/README.md

@@ -18,21 +18,21 @@ The above command will generate a `.test_optimizer.dart` in the `test` directory
 // GENERATED CODE - DO NOT MODIFY BY HAND
 // Consider adding this file to your .gitignore.
 
-import 'app/view/app_test.dart' as app_view_app_test_dart;
-import 'counter/cubit/counter_cubit_test.dart' as counter_cubit_counter_cubit_test_dart;
-import 'counter/view/counter_page_test.dart' as counter_view_counter_page_test_dart;
+import 'app/view/app_test.dart' as _a;
+import 'counter/cubit/counter_cubit_test.dart' as _b;
+import 'counter/view/counter_page_test.dart' as _c;
 
 void main() {
-  app_view_app_test_dart.main();
-  counter_cubit_counter_cubit_test_dart.main();
-  counter_view_counter_page_test_dart.main();
+  group('app/view/app_test.dart.dart', () { _a.main(); });
+  group('counter/cubit/counter_cubit_test.dart', () { _b.main(); });
+  group('counter/view/counter_page_test.dart', () { _c.main(); });
 }
 ```
 
 [1]: https://github.com/felangel/mason
 
---- 
+---
 
 ### Note for maintainers
 
-After changing this brick, make sure to run `./tools/generate_test_optimizer_bundle.sh` from the root of the repository to update the bundle.
+After changing this brick, make sure to run `./tools/generate_test_optimizer_bundle.sh` from the root of the repository to update the bundle.

bricks/test_optimizer/brick.yaml

@@ -10,4 +10,4 @@ vars:
     type: string
     default: "."
     description: The path to the package root.
-    prompt: Please enter the path to the package root.
+    prompt: Please enter the path to the package root.

bricks/test_optimizer/hooks/lib/dart_identifier_generator.dart

@@ -0,0 +1,35 @@
+/// {@template DartIdentifierGenerator}
+/// A class that generates valid Dart identifiers.
+///
+/// See also:
+///
+/// * Section 17.37 from [Dart Language Specification](https://dart.dev/guides/language/specifications/DartLangSpec-v2.10.pdf)
+/// {@endtemplate}
+class DartIdentifierGenerator {
+  /// {@macro DartIdentifierGenerator}
+  DartIdentifierGenerator([
+    this._chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',
+  ]) : _nextId = [0];
+
+  final String _chars;
+  final List<int> _nextId;
+
+  /// Generate the next short identifier.
+  String next() {
+    final r = <String>['_', for (final char in _nextId) _chars[char]];
+    _increment();
+    return r.join();
+  }
+
+  void _increment() {
+    for (var i = 0; i < _nextId.length; i++) {
+      final val = ++_nextId[i];
+      if (val >= _chars.length) {
+        _nextId[i] = 0;
+      } else {
+        return;
+      }
+    }
+    _nextId.add(0);
+  }
+}

bricks/test_optimizer/hooks/lib/pre_gen.dart

@@ -2,6 +2,7 @@
 
 import 'dart:io';
 
+import 'package:hooks/dart_identifier_generator.dart';
 import 'package:mason/mason.dart';
 import 'package:path/path.dart' as path;
 
@@ -28,17 +29,19 @@ Future<void> run(HookContext context) async {
   final flutterSdkRegExp = RegExp(r'sdk:\s*flutter$', multiLine: true);
   final isFlutter = flutterSdkRegExp.hasMatch(pubspecContents);
 
-  final tests = testDir
-      .listSync(recursive: true)
-      .where((entity) => entity.isTest)
-      .map(
-        (entity) => path
-            .relative(entity.path, from: testDir.path)
-            .replaceAll(r'\', '/'),
-      )
-      .toList();
-
-  context.vars = {'tests': tests, 'isFlutter': isFlutter};
+  final identifierGenerator = DartIdentifierGenerator();
+  final testIdentifierTable = <Map<String, String>>[];
+  for (final entity
+      in testDir.listSync(recursive: true).where((entity) => entity.isTest)) {
+    final relativePath =
+        path.relative(entity.path, from: testDir.path).replaceAll(r'\', '/');
+    testIdentifierTable.add({
+      'path': relativePath,
+      'identifier': identifierGenerator.next(),
+    });
+  }
+
+  context.vars = {'tests': testIdentifierTable, 'isFlutter': isFlutter};
 }
 
 extension on FileSystemEntity {

bricks/test_optimizer/hooks/test/dart_identifier_generator_test.dart

@@ -0,0 +1,136 @@
+import 'package:hooks/dart_identifier_generator.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group('$DartIdentifierGenerator', () {
+    test('can be instantiated', () {
+      expect(DartIdentifierGenerator.new, returnsNormally);
+    });
+
+    group('next', () {
+      test('returns normally', () {
+        final generator = DartIdentifierGenerator();
+        expect(generator.next, returnsNormally);
+      });
+
+      test('generates unique strings', () {
+        final generator = DartIdentifierGenerator();
+        final ids = <String>{};
+        const count = 1000;
+        for (var i = 0; i < count; i++) {
+          final id = generator.next();
+          ids.add(id);
+        }
+        expect(ids.length, count);
+      });
+
+      test('generates valid dart identifiers', () {
+        // For a full specification of valid dart identifiers, read
+        // Section 17.37 from the [Dart Language Specification](https://dart.dev/guides/language/specifications/DartLangSpec-v2.10.pdf).
+        final generator = DartIdentifierGenerator();
+        final ids = <String>[];
+        for (var i = 0; i < 1000; i++) {
+          final id = generator.next();
+          ids.add(id);
+        }
+
+        expect(
+          ids.where((id) => _dartReservedKeywords.contains(id)),
+          isEmpty,
+        );
+        expect(
+          ids.every((id) {
+            final idStart = id.codeUnitAt(0);
+            final isAlphabetic = (idStart >= 65 && idStart <= 90) ||
+                (idStart >= 97 && idStart <= 122);
+            final isUnderscore = idStart == 95;
+            final isDollarSign = idStart == 36;
+            return isAlphabetic || isUnderscore || isDollarSign;
+          }),
+          true,
+        );
+        expect(
+          ids.every((id) {
+            final idPart = id.codeUnits.skip(1);
+            return idPart.every((ascii) {
+              final isAlphabetic =
+                  (ascii >= 65 && ascii <= 90) || (ascii >= 97 && ascii <= 122);
+              final isUnderscore = ascii == 95;
+              final isDollarSign = ascii == 36;
+              final isDigit = ascii >= 48 && ascii <= 57;
+              return isAlphabetic || isUnderscore || isDollarSign || isDigit;
+            });
+          }),
+          true,
+        );
+      });
+    });
+  });
+}
+
+// All reserved keywords in [Dart 2.19.2](https://dart.dev/guides/language/language-tour#keywords).
+const _dartReservedKeywords = [
+  'abstract',
+  'as',
+  'assert',
+  'async',
+  'await',
+  'break',
+  'case',
+  'catch',
+  'class',
+  'const',
+  'continue',
+  'covariant',
+  'default',
+  'deferred',
+  'do',
+  'dynamic',
+  'else',
+  'enum',
+  'export',
+  'extends',
+  'extension',
+  'external',
+  'factory',
+  'false',
+  'final',
+  'finally',
+  'for',
+  'Function',
+  'get',
+  'hide',
+  'if',
+  'implements',
+  'import',
+  'in',
+  'interface',
+  'is',
+  'late',
+  'library',
+  'mixin',
+  'new',
+  'null',
+  'on',
+  'operator',
+  'part',
+  'required',
+  'rethrow',
+  'return',
+  'set',
+  'show',
+  'static',
+  'super',
+  'switch',
+  'sync',
+  'this',
+  'throw',
+  'true',
+  'try',
+  'typedef',
+  'var',
+  'void',
+  'while',
+  'with',
+  'yield',
+];

bricks/test_optimizer/hooks/test/pre_gen_test.dart

@@ -42,16 +42,15 @@ void main() {
 
         await pre_gen.run(context);
 
-        final tests = context.vars['tests'] as List<String>;
+        final tests = context.vars['tests'] as List<Map<String, String>>;
 
         expect(
           tests,
-          containsAll([
-            'test2_test.dart',
-            'test1_test.dart',
+          equals([
+            {'path': 'test2_test.dart', 'identifier': '_a'},
+            {'path': 'test1_test.dart', 'identifier': '_b'},
           ]),
         );
-        expect(test, isNot(contains('no_test_here.dart')));
         expect(context.vars['isFlutter'], false);
       });