More consistent temp directory naming (#42063)

Applying our style guide:
https://github.com/flutter/flutter/wiki/Style-guide-for-Flutter-repo#have-good-hygiene-when-using-temporary-directories

packages/flutter_tools/lib/src/build_runner/web_fs.dart

@@ -413,7 +413,7 @@ class DebugAssetServer extends AssetServer {
         ));
         if (dart2jsArchive.existsSync()) {
           final Archive archive = TarDecoder().decodeBytes(dart2jsArchive.readAsBytesSync());
-          partFiles = fs.systemTempDirectory.createTempSync('_flutter_tool')
+          partFiles = fs.systemTempDirectory.createTempSync('flutter_tool.')
             ..createSync();
           for (ArchiveFile file in archive) {
             partFiles.childFile(file.name).writeAsBytesSync(file.content);

packages/flutter_tools/lib/src/cache.dart

@@ -885,7 +885,7 @@ class AndroidMavenArtifacts extends ArtifactSet {
   @override
   Future<void> update() async {
     final Directory tempDir =
-        fs.systemTempDirectory.createTempSync('gradle_wrapper.');
+        fs.systemTempDirectory.createTempSync('flutter_gradle_wrapper.');
     injectGradleWrapperIfNeeded(tempDir);
 
     final Status status = logger.startProgress('Downloading Android Maven dependencies...',

packages/flutter_tools/lib/src/resident_runner.dart

@@ -545,7 +545,7 @@ abstract class ResidentRunner {
        packagesFilePath = packagesFilePath ?? fs.path.absolute(PackageMap.globalPackagesPath),
        _dillOutputPath = dillOutputPath,
        artifactDirectory = dillOutputPath == null
-          ? fs.systemTempDirectory.createTempSync('_fluttter_tool')
+          ? fs.systemTempDirectory.createTempSync('flutter_tool.')
           : fs.file(dillOutputPath).parent,
        assetBundle = AssetBundleFactory.instance.createBundle() {
     if (!artifactDirectory.existsSync()) {

packages/flutter_tools/lib/src/test/runner.dart

@@ -63,7 +63,7 @@ Future<int> runTests(
   ];
   if (web) {
     final String tempBuildDir = fs.systemTempDirectory
-      .createTempSync('_flutter_test')
+      .createTempSync('flutter_test.')
       .absolute
       .uri
       .toFilePath();

packages/flutter_tools/lib/src/web/chrome.dart

@@ -89,7 +89,7 @@ class ChromeLauncher {
   /// `skipCheck` does not attempt to make a devtools connection before returning.
   Future<Chrome> launch(String url, { bool headless = false, bool skipCheck = false }) async {
     final String chromeExecutable = findChromeExecutable();
-    final Directory dataDir = fs.systemTempDirectory.createTempSync('flutter_tool_');
+    final Directory dataDir = fs.systemTempDirectory.createTempSync('flutter_tool.');
     final int port = await os.findFreePort();
     final List<String> args = <String>[
       chromeExecutable,

packages/flutter_tools/test/general.shard/android/gradle_test.dart

@@ -444,7 +444,7 @@ someOtherTask
 
     setUp(() {
       mockLogger = BufferLogger();
-      tempDir = fs.systemTempDirectory.createTempSync('settings_aar_test.');
+      tempDir = fs.systemTempDirectory.createTempSync('flutter_settings_aar_test.');
 
     });
 
@@ -852,7 +852,7 @@ flutter:
 
     setUp(() {
       fs = MemoryFileSystem();
-      tempDir = fs.systemTempDirectory.createTempSync('artifacts_test.');
+      tempDir = fs.systemTempDirectory.createTempSync('flutter_artifacts_test.');
       gradleBinary = platform.isWindows ? 'gradlew.bat' : 'gradlew';
       gradleWrapperDirectory = fs.directory(
         fs.path.join(tempDir.path, 'bin', 'cache', 'artifacts', 'gradle_wrapper'));
@@ -960,7 +960,7 @@ at org.gradle.wrapper.GradleWrapperMain.main(GradleWrapperMain.java:61)''';
 
     setUp(() {
       memoryFileSystem = MemoryFileSystem();
-      tempDir = memoryFileSystem.systemTempDirectory.createTempSync('artifacts_test.');
+      tempDir = memoryFileSystem.systemTempDirectory.createTempSync('flutter_artifacts_test.');
       gradleWrapperDirectory = memoryFileSystem.directory(
           memoryFileSystem.path.join(tempDir.path, 'bin', 'cache', 'artifacts', 'gradle_wrapper'));
       gradleWrapperDirectory.createSync(recursive: true);
@@ -1157,7 +1157,7 @@ at org.gradle.wrapper.GradleWrapperMain.main(GradleWrapperMain.java:61)''';
     });
 
     testUsingContext('returns true when the project is using AndroidX', () async {
-      final Directory androidDirectory = fs.systemTempDirectory.createTempSync('android.');
+      final Directory androidDirectory = fs.systemTempDirectory.createTempSync('flutter_android.');
 
       androidDirectory
         .childFile('gradle.properties')
@@ -1170,7 +1170,7 @@ at org.gradle.wrapper.GradleWrapperMain.main(GradleWrapperMain.java:61)''';
     });
 
     testUsingContext('returns false when the project is not using AndroidX', () async {
-      final Directory androidDirectory = fs.systemTempDirectory.createTempSync('android.');
+      final Directory androidDirectory = fs.systemTempDirectory.createTempSync('flutter_android.');
 
       androidDirectory
         .childFile('gradle.properties')
@@ -1183,7 +1183,7 @@ at org.gradle.wrapper.GradleWrapperMain.main(GradleWrapperMain.java:61)''';
     });
 
     testUsingContext('returns false when gradle.properties does not exist', () async {
-      final Directory androidDirectory = fs.systemTempDirectory.createTempSync('android.');
+      final Directory androidDirectory = fs.systemTempDirectory.createTempSync('flutter_android.');
 
       expect(isAppUsingAndroidX(androidDirectory), isFalse);
 
@@ -1313,7 +1313,7 @@ plugin2=${plugin2.path}
       mockProcessManager = MockProcessManager();
       android = fakePlatform('android');
 
-      final Directory tempDir = fs.systemTempDirectory.createTempSync('artifacts_test.');
+      final Directory tempDir = fs.systemTempDirectory.createTempSync('flutter_artifacts_test.');
       cache = Cache(rootOverride: tempDir);
 
       final Directory gradleWrapperDirectory = tempDir

packages/flutter_tools/test/general.shard/application_package_test.dart

@@ -107,7 +107,7 @@ void main() {
         .childFile('gradle.properties')
         .writeAsStringSync('irrelevant');
 
-      final Directory gradleWrapperDir = fs.systemTempDirectory.createTempSync('gradle_wrapper.');
+      final Directory gradleWrapperDir = fs.systemTempDirectory.createTempSync('flutter_application_package_test_gradle_wrapper.');
       when(mockCache.getArtifactDirectory('gradle_wrapper')).thenReturn(gradleWrapperDir);
 
       fs.directory(gradleWrapperDir.childDirectory('gradle').childDirectory('wrapper'))

packages/flutter_tools/test/general.shard/artifacts_test.dart

@@ -19,7 +19,7 @@ void main() {
 
     setUp(() {
       memoryFileSystem = MemoryFileSystem();
-      tempDir = memoryFileSystem.systemTempDirectory.createTempSync('artifacts_test.');
+      tempDir = memoryFileSystem.systemTempDirectory.createTempSync('flutter_artifacts_test.');
     });
 
     tearDown(() {

packages/flutter_tools/test/general.shard/cache_test.dart

@@ -234,8 +234,8 @@ void main() {
     });
 
     testUsingContext('makes binary dirs readable and executable by all', () async {
-      final Directory artifactDir = fs.systemTempDirectory.createTempSync('artifact.');
-      final Directory downloadDir = fs.systemTempDirectory.createTempSync('download.');
+      final Directory artifactDir = fs.systemTempDirectory.createTempSync('flutter_cache_test_artifact.');
+      final Directory downloadDir = fs.systemTempDirectory.createTempSync('flutter_cache_test_download.');
       when(mockCache.getArtifactDirectory(any)).thenReturn(artifactDir);
       when(mockCache.getDownloadDir()).thenReturn(downloadDir);
       final FakeCachedArtifact artifact = FakeCachedArtifact(
@@ -282,7 +282,7 @@ void main() {
       final AndroidMavenArtifacts mavenArtifacts = AndroidMavenArtifacts();
       expect(mavenArtifacts.isUpToDate(), isFalse);
 
-      final Directory gradleWrapperDir = fs.systemTempDirectory.createTempSync('gradle_wrapper.');
+      final Directory gradleWrapperDir = fs.systemTempDirectory.createTempSync('flutter_cache_test_gradle_wrapper.');
       when(mockCache.getArtifactDirectory('gradle_wrapper')).thenReturn(gradleWrapperDir);
 
       fs.directory(gradleWrapperDir.childDirectory('gradle').childDirectory('wrapper'))

packages/flutter_tools/test/general.shard/plugins_test.dart

@@ -197,7 +197,7 @@ flutter:
       when(androidProject.appManifestFile).thenReturn(androidManifest);
 
       final Directory pluginUsingJavaAndNewEmbeddingDir =
-        fs.systemTempDirectory.createTempSync('pluginUsingJavaAndNewEmbeddingDir.');
+        fs.systemTempDirectory.createTempSync('flutter_plugin_using_java_and_new_embedding_dir.');
       pluginUsingJavaAndNewEmbeddingDir
         .childFile('pubspec.yaml')
         .writeAsStringSync('''
@@ -217,7 +217,7 @@ flutter:
         ..writeAsStringSync('import io.flutter.embedding.engine.plugins.FlutterPlugin;');
 
       final Directory pluginUsingKotlinAndNewEmbeddingDir =
-        fs.systemTempDirectory.createTempSync('pluginUsingKotlinAndNewEmbeddingDir.');
+        fs.systemTempDirectory.createTempSync('flutter_plugin_using_kotlin_and_new_embedding_dir.');
       pluginUsingKotlinAndNewEmbeddingDir
         .childFile('pubspec.yaml')
         .writeAsStringSync('''
@@ -237,7 +237,7 @@ flutter:
         ..writeAsStringSync('import io.flutter.embedding.engine.plugins.FlutterPlugin');
 
       final Directory pluginUsingOldEmbeddingDir =
-        fs.systemTempDirectory.createTempSync('pluginUsingOldEmbeddingDir.');
+        fs.systemTempDirectory.createTempSync('flutter_plugin_using_old_embedding_dir.');
       pluginUsingOldEmbeddingDir
         .childFile('pubspec.yaml')
         .writeAsStringSync('''

packages/flutter_tools/test/general.shard/resident_runner_test.dart

@@ -306,7 +306,7 @@ void main() {
   }));
 
   test('ResidentRunner uses temp directory when there is no output dill path', () => testbed.run(() {
-    expect(residentRunner.artifactDirectory.path, contains('_fluttter_tool'));
+    expect(residentRunner.artifactDirectory.path, contains('flutter_tool.'));
 
     final ResidentRunner otherRunner = HotRunner(
       <FlutterDevice>[

packages/flutter_tools/test/integration.shard/test_utils.dart

@@ -15,8 +15,9 @@ import '../src/common.dart';
 /// underlying path to avoid issues with breakpoints/hot reload.
 /// https://github.com/flutter/flutter/pull/21741
 Directory createResolvedTempDirectorySync(String prefix) {
-  final Directory tempDir = fs.systemTempDirectory.createTempSync('flutter_$prefix');
-  return fs.directory(tempDir.resolveSymbolicLinksSync());
+  assert(prefix.endsWith('.'));
+  final Directory tempDirectory = fs.systemTempDirectory.createTempSync('flutter_$prefix');
+  return fs.directory(tempDirectory.resolveSymbolicLinksSync());
 }
 
 void writeFile(String path, String content) {