Replace clean command test functions with test groups (#51508)

packages/flutter_tools/test/commands.shard/hermetic/clean_test.dart

@@ -18,16 +18,27 @@ import '../../src/common.dart';
 import '../../src/context.dart';
 
 void main() {
-  void test1() {
-    final MemoryFileSystem fs = MemoryFileSystem();
-    final MockXcodeProjectInterpreter mockXcodeProjectInterpreter = MockXcodeProjectInterpreter();
-    final MockXcode mockXcode = MockXcode();
+  group('clean command', () {
+    MockXcode mockXcode;
+    setUp(() {
+      mockXcode = MockXcode();
+    });
+
+    group('general', () {
+      MemoryFileSystem fs;
+      MockXcodeProjectInterpreter mockXcodeProjectInterpreter;
+      Directory buildDirectory;
+      FlutterProject projectUnderTest;
+
+      setUp(() {
+        fs = MemoryFileSystem();
+        mockXcodeProjectInterpreter = MockXcodeProjectInterpreter();
 
         final Directory currentDirectory = fs.currentDirectory;
-    final Directory buildDirectory = currentDirectory.childDirectory('build');
+        buildDirectory = currentDirectory.childDirectory('build');
         buildDirectory.createSync(recursive: true);
 
-    final FlutterProject projectUnderTest = FlutterProject.fromDirectory(currentDirectory);
+        projectUnderTest = FlutterProject.fromDirectory(currentDirectory);
         projectUnderTest.ios.xcodeWorkspace.createSync(recursive: true);
         projectUnderTest.macos.xcodeWorkspace.createSync(recursive: true);
 
@@ -37,6 +48,7 @@ void main() {
         projectUnderTest.linux.ephemeralDirectory.createSync(recursive: true);
         projectUnderTest.macos.ephemeralDirectory.createSync(recursive: true);
         projectUnderTest.windows.ephemeralDirectory.createSync(recursive: true);
+      });
 
       testUsingContext('$CleanCommand removes build and .dart_tool and ephemeral directories, cleans Xcode', () async {
         when(mockXcode.isInstalledAndMeetsVersionCheck).thenReturn(true);
@@ -57,11 +69,14 @@ void main() {
         Xcode: () => mockXcode,
         XcodeProjectInterpreter: () => mockXcodeProjectInterpreter,
       });
-  }
+    });
+
+    group('Windows', () {
+      MockPlatform windowsPlatform;
+      setUp(() {
+        windowsPlatform = MockPlatform();
+      });
 
-  void test2() {
-    final MockXcode mockXcode = MockXcode();
-    final MockPlatform windowsPlatform = MockPlatform();
       testUsingContext('$CleanCommand prints a helpful error message on Windows', () async {
         when(mockXcode.isInstalledAndMeetsVersionCheck).thenReturn(false);
         when(windowsPlatform.isWindows).thenReturn(true);
@@ -94,10 +109,8 @@ void main() {
         Platform: () => windowsPlatform,
         Xcode: () => mockXcode,
       });
-  }
-
-  test1();
-  test2();
+    });
+  });
 }
 
 class MockFile extends Mock implements File {}