[flutter_tools] migrate more unit tests to null safety (#106153)

Author: Jonah Williams

packages/flutter_tools/lib/src/build_system/targets/assets.dart

@@ -210,10 +210,10 @@ DevFSContent? processSkSLBundle(String? bundlePath, {
   }
 
   // Step 2: validate top level bundle structure.
-  Map<String, Object>? bundle;
+  Map<String, Object?>? bundle;
   try {
     final Object? rawBundle = json.decode(skSLBundleFile.readAsStringSync());
-    if (rawBundle is Map<String, Object>) {
+    if (rawBundle is Map<String, Object?>) {
       bundle = rawBundle;
     } else {
       logger.printError('"$bundle" was not a JSON object: $rawBundle');

packages/flutter_tools/lib/src/cache.dart

@@ -389,10 +389,10 @@ class Cache {
         throw Exception('Could not find file at $versionFilePath');
       }
       final dynamic data = jsonDecode(versionFile.readAsStringSync());
-      if (data is! Map<String, Object>) {
-        throw Exception("Expected object of type 'Map<String, Object>' but got one of type '${data.runtimeType}'");
+      if (data is! Map<String, Object?>) {
+        throw Exception("Expected object of type 'Map<String, Object?>' but got one of type '${data.runtimeType}'");
       }
-      final dynamic version = data['version'];
+      final Object? version = data['version'];
       if (version == null) {
         throw Exception('Could not parse DevTools version from $version');
       }

packages/flutter_tools/lib/src/commands/create_base.dart

@@ -668,11 +668,11 @@ abstract class CreateBase extends FlutterCommand {
       'templates',
       'template_manifest.json',
     );
-    final Map<String, Object> manifest = json.decode(
+    final Map<String, Object?> manifest = json.decode(
       globals.fs.file(manifestPath).readAsStringSync(),
-    ) as Map<String, Object>;
+    ) as Map<String, Object?>;
     return Set<Uri>.from(
-      (manifest['files']! as List<Object>).cast<String>().map<Uri>(
+      (manifest['files']! as List<Object?>).cast<String>().map<Uri>(
           (String path) =>
               Uri.file(globals.fs.path.join(flutterToolsAbsolutePath, path))),
     );

packages/flutter_tools/lib/src/macos/application_package.dart

@@ -86,8 +86,8 @@ abstract class MacOSApp extends ApplicationPackage {
       return null;
     }
     final Map<String, dynamic> propertyValues = globals.plistParser.parseFile(plistPath);
-    final String id = propertyValues[PlistParser.kCFBundleIdentifierKey] as String;
-    final String executableName = propertyValues[PlistParser.kCFBundleExecutable] as String;
+    final String? id = propertyValues[PlistParser.kCFBundleIdentifierKey] as String?;
+    final String? executableName = propertyValues[PlistParser.kCFBundleExecutable] as String?;
     if (id == null) {
       globals.printError('Invalid prebuilt macOS app. Info.plist does not contain bundle identifier');
       return null;

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

@@ -1534,7 +1534,7 @@ abstract class FlutterCommand extends Command<void> {
     if (!argParser.options.containsKey(name)) {
       return null;
     }
-    return argResults![name] as String;
+    return argResults![name] as String?;
   }
 
   /// Gets the parsed command-line option named [name] as an `int`.

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

@@ -117,7 +117,7 @@ class CoverageCollector extends TestWatcher {
     );
 
     final Future<void> collectionComplete = testDevice.observatoryUri
-      .then((Uri observatoryUri) {
+      .then((Uri? observatoryUri) {
         _logMessage('collecting coverage data from $testDevice at $observatoryUri...');
         return collect(observatoryUri, libraryNames)
           .then<void>((Map<String, dynamic> result) {

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

@@ -494,7 +494,7 @@ class FlutterPlatform extends PlatformPlugin {
       await Future.any<void>(<Future<void>>[
         testDevice.finished,
         () async {
-          final Uri processObservatoryUri = await testDevice.observatoryUri;
+          final Uri? processObservatoryUri = await testDevice.observatoryUri;
           if (processObservatoryUri != null) {
             globals.printTrace('test $ourTestCount: Observatory uri is available at $processObservatoryUri');
           } else {

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

@@ -47,8 +47,7 @@ class FlutterTesterTestDevice extends TestDevice {
   })  : assert(shellPath != null), // Please provide the path to the shell in the SKY_SHELL environment variable.
         assert(!debuggingOptions.startPaused || enableObservatory),
         _gotProcessObservatoryUri = enableObservatory
-            // ignore: null_argument_to_non_null_type
-            ? Completer<Uri>() : (Completer<Uri>()..complete()),
+            ? Completer<Uri?>() : (Completer<Uri?>()..complete()),
         _operatingSystemUtils = OperatingSystemUtils(
           fileSystem: fileSystem,
           logger: logger,
@@ -73,7 +72,7 @@ class FlutterTesterTestDevice extends TestDevice {
   final CompileExpression? compileExpression;
   final FontConfigManager fontConfigManager;
 
-  final Completer<Uri> _gotProcessObservatoryUri;
+  final Completer<Uri?> _gotProcessObservatoryUri;
   final Completer<int> _exitCode = Completer<int>();
 
   Process? _process;
@@ -209,7 +208,7 @@ class FlutterTesterTestDevice extends TestDevice {
   }
 
   @override
-  Future<Uri> get observatoryUri {
+  Future<Uri?> get observatoryUri {
     assert(_gotProcessObservatoryUri != null);
     return _gotProcessObservatoryUri.future;
   }

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

@@ -79,7 +79,7 @@ class TestCompiler {
   late File outputDill;
 
   Future<String?> compile(Uri mainDart) {
-    final Completer<String> completer = Completer<String>();
+    final Completer<String?> completer = Completer<String?>();
     if (compilerController.isClosed) {
       return Future<String?>.value();
     }
@@ -175,7 +175,7 @@ class TestCompiler {
       // compiler to avoid reusing compiler that might have gotten into
       // a weird state.
       if (outputPath == null || compilerOutput!.errorCount > 0) {
-        request.result.complete(null);
+        request.result.complete();
         await _shutdown();
       } else {
         if (shouldCopyDillFile) {

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

@@ -22,7 +22,7 @@ abstract class TestDevice {
   Future<StreamChannel<String>> start(String entrypointPath);
 
   /// Should complete with null if the observatory is not enabled.
-  Future<Uri> get observatoryUri;
+  Future<Uri?> get observatoryUri;
 
   /// Terminates the test device.
   Future<void> kill();