diff --git a/packages/pigeon/README.md b/packages/pigeon/README.md
index 699cffdb96e9..a4e5a0c8f95f 100644
--- a/packages/pigeon/README.md
+++ b/packages/pigeon/README.md
@@ -78,7 +78,7 @@ Example:
 
 ```dart
 class Value {
-  int number;
+  int? number;
 }
 
 @HostApi()
diff --git a/packages/pigeon/example/README.md b/packages/pigeon/example/README.md
index 0c8fdb8ee27e..a6d18e36a265 100644
--- a/packages/pigeon/example/README.md
+++ b/packages/pigeon/example/README.md
@@ -14,11 +14,11 @@ from Flutter to the host-platform.
 import 'package:pigeon/pigeon.dart';
 
 class SearchRequest {
-  String query;
+  String? query;
 }
 
 class SearchReply {
-  String result;
+  String? result;
 }
 
 @HostApi()
diff --git a/packages/pigeon/lib/ast.dart b/packages/pigeon/lib/ast.dart
index 747a7ed56d48..95fb026a9c9b 100644
--- a/packages/pigeon/lib/ast.dart
+++ b/packages/pigeon/lib/ast.dart
@@ -17,8 +17,12 @@ class Node {}
 /// Represents a method on an [Api].
 class Method extends Node {
   /// Parametric constructor for [Method].
-  Method(
-      {this.name, this.returnType, this.argType, this.isAsynchronous = false});
+  Method({
+    required this.name,
+    required this.returnType,
+    required this.argType,
+    this.isAsynchronous = false,
+  });
 
   /// The name of the method.
   String name;
@@ -36,7 +40,12 @@ class Method extends Node {
 /// Represents a collection of [Method]s that are hosted on a given [location].
 class Api extends Node {
   /// Parametric constructor for [Api].
-  Api({this.name, this.location, this.methods, this.dartHostTestHandler});
+  Api({
+    required this.name,
+    required this.location,
+    required this.methods,
+    this.dartHostTestHandler,
+  });
 
   /// The name of the API.
   String name;
@@ -48,13 +57,16 @@ class Api extends Node {
   List<Method> methods;
 
   /// The name of the Dart test interface to generate to help with testing.
-  String dartHostTestHandler;
+  String? dartHostTestHandler;
 }
 
 /// Represents a field on a [Class].
 class Field extends Node {
   /// Parametric constructor for [Field].
-  Field({this.name, this.dataType});
+  Field({
+    required this.name,
+    required this.dataType,
+  });
 
   /// The name of the field.
   String name;
@@ -71,7 +83,10 @@ class Field extends Node {
 /// Represents a class with [Field]s.
 class Class extends Node {
   /// Parametric constructor for [Class].
-  Class({this.name, this.fields});
+  Class({
+    required this.name,
+    required this.fields,
+  });
 
   /// The name of the class.
   String name;
@@ -88,7 +103,10 @@ class Class extends Node {
 /// Top-level node for the AST.
 class Root extends Node {
   /// Parametric constructor for [Root].
-  Root({this.classes, this.apis});
+  Root({
+    required this.classes,
+    required this.apis,
+  });
 
   /// All the classes contained in the AST.
   List<Class> classes;
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index 168ac86f42a1..f36b62e79b83 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -33,7 +33,7 @@ void _writeHostApi(DartOptions opt, Indent indent, Api api) {
       }
       String argSignature = '';
       String sendArgument = 'null';
-      String encodedDeclaration;
+      String? encodedDeclaration;
       if (func.argType != 'void') {
         argSignature = '${func.argType} arg';
         sendArgument = 'encoded';
@@ -47,17 +47,18 @@ void _writeHostApi(DartOptions opt, Indent indent, Api api) {
           indent.writeln(encodedDeclaration);
         }
         final String channelName = makeChannelName(api, func);
-        indent.writeln('const BasicMessageChannel<Object$nullTag> channel =');
+        indent.writeln(
+            'const BasicMessageChannel<Object$nullTag> channel = BasicMessageChannel<Object$nullTag>(');
         indent.nest(2, () {
           indent.writeln(
-            'BasicMessageChannel<Object$nullTag>(\'$channelName\', StandardMessageCodec());',
+            '\'$channelName\', StandardMessageCodec());',
           );
         });
         final String returnStatement = func.returnType == 'void'
             ? '// noop'
             : 'return ${func.returnType}.decode(replyMap[\'${Keys.result}\']$unwrapOperator);';
         indent.format('''
-final Map<Object$nullTag, Object$nullTag>$nullTag replyMap = await channel.send($sendArgument) as Map<Object$nullTag, Object$nullTag>$nullTag;
+final Map<Object$nullTag, Object$nullTag>$nullTag replyMap =\n\t\tawait channel.send($sendArgument) as Map<Object$nullTag, Object$nullTag>$nullTag;
 if (replyMap == null) {
 \tthrow PlatformException(
 \t\tcode: 'channel-error',
@@ -83,7 +84,7 @@ void _writeFlutterApi(
   DartOptions opt,
   Indent indent,
   Api api, {
-  String Function(Method) channelNameFunc,
+  String Function(Method)? channelNameFunc,
   bool isMockHandler = false,
 }) {
   assert(api.location == ApiLocation.flutter);
@@ -105,14 +106,14 @@ void _writeFlutterApi(
         indent.write('');
         indent.scoped('{', '}', () {
           indent.writeln(
-            'const BasicMessageChannel<Object$nullTag> channel =',
+            'const BasicMessageChannel<Object$nullTag> channel = BasicMessageChannel<Object$nullTag>(',
           );
           final String channelName = channelNameFunc == null
               ? makeChannelName(api, func)
               : channelNameFunc(func);
           indent.nest(2, () {
             indent.writeln(
-              'BasicMessageChannel<Object$nullTag>(\'$channelName\', StandardMessageCodec());',
+              '\'$channelName\', StandardMessageCodec());',
             );
           });
           final String messageHandlerSetter =
@@ -248,9 +249,10 @@ void generateDart(DartOptions opt, Root root, StringSink sink) {
             final Field field = klass.fields[index];
             indent.write('..${field.name} = ');
             if (customClassNames.contains(field.dataType)) {
-              indent.add(
-                'pigeonMap[\'${field.name}\'] != null ? ${field.dataType}.decode(pigeonMap[\'${field.name}\']$unwrapOperator) : null',
-              );
+              indent.format('''
+pigeonMap['${field.name}'] != null
+\t\t? ${field.dataType}.decode(pigeonMap['${field.name}']$unwrapOperator)
+\t\t: null''', leadingSpace: false, trailingNewline: false);
             } else {
               indent.add(
                 'pigeonMap[\'${field.name}\'] as ${_addGenericTypes(field.dataType, nullTag)}',
@@ -300,9 +302,10 @@ void generateTestDart(
   for (final Api api in root.apis) {
     if (api.location == ApiLocation.host && api.dartHostTestHandler != null) {
       final Api mockApi = Api(
-        name: api.dartHostTestHandler,
+        name: api.dartHostTestHandler!,
         methods: api.methods,
         location: ApiLocation.flutter,
+        dartHostTestHandler: api.dartHostTestHandler,
       );
       indent.writeln('');
       _writeFlutterApi(
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index 895c58e97bf3..c1cf021ee9c0 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -8,7 +8,7 @@ import 'dart:mirrors';
 import 'ast.dart';
 
 /// The current version of pigeon. This must match the version in pubspec.yaml.
-const String pigeonVersion = '0.1.24';
+const String pigeonVersion = '0.2.0';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {
@@ -55,17 +55,26 @@ class Indent {
   }
 
   /// Replaces the newlines and tabs of input and adds it to the stream.
-  void format(String input) {
-    for (final String line in input.split('\n')) {
-      writeln(line.replaceAll('\t', tab));
+  void format(String input,
+      {bool leadingSpace = true, bool trailingNewline = true}) {
+    final List<String> lines = input.split('\n');
+    for (int i = 0; i < lines.length; ++i) {
+      final String line = lines[i];
+      if (i == 0 && !leadingSpace) {
+        addln(line.replaceAll('\t', tab));
+      } else if (i == lines.length - 1 && !trailingNewline) {
+        write(line.replaceAll('\t', tab));
+      } else {
+        writeln(line.replaceAll('\t', tab));
+      }
     }
   }
 
   /// Scoped increase of the ident level.  For the execution of [func] the
   /// indentation will be incremented.
   void scoped(
-    String begin,
-    String end,
+    String? begin,
+    String? end,
     Function func, {
     bool addTrailingNewline = true,
   }) {
@@ -83,12 +92,12 @@ class Indent {
 
   /// Like `scoped` but writes the current indentation level.
   void writeScoped(
-    String begin,
+    String? begin,
     String end,
     Function func, {
     bool addTrailingNewline = true,
   }) {
-    scoped(str() + begin ?? '', end, func,
+    scoped(str() + (begin ?? ''), end, func,
         addTrailingNewline: addTrailingNewline);
   }
 
@@ -133,7 +142,10 @@ String makeChannelName(Api api, Method func) {
 /// Represents the mapping of a Dart datatype to a Host datatype.
 class HostDatatype {
   /// Parametric constructor for HostDatatype.
-  HostDatatype({this.datatype, this.isBuiltin});
+  HostDatatype({
+    required this.datatype,
+    required this.isBuiltin,
+  });
 
   /// The [String] that can be printed into host code to represent the type.
   final String datatype;
@@ -147,9 +159,9 @@ class HostDatatype {
 /// `builtinResolver` will return the host datatype for the Dart datatype for
 /// builtin types.  `customResolver` can modify the datatype of custom types.
 HostDatatype getHostDatatype(
-    Field field, List<Class> classes, String Function(String) builtinResolver,
-    {String Function(String) customResolver}) {
-  final String datatype = builtinResolver(field.dataType);
+    Field field, List<Class> classes, String? Function(String) builtinResolver,
+    {String Function(String)? customResolver}) {
+  final String? datatype = builtinResolver(field.dataType);
   if (datatype == null) {
     if (classes.map((Class x) => x.name).contains(field.dataType)) {
       final String customName = customResolver != null
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index 2c119e8ed58a..9f1d307c3784 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -20,11 +20,17 @@ const Map<String, String> _javaTypeForDartTypeMap = <String, String>{
 
 /// Options that control how Java code will be generated.
 class JavaOptions {
+  /// Creates a [JavaOptions] object
+  JavaOptions({
+    this.className,
+    this.package,
+  });
+
   /// The name of the class that will house all the generated classes.
-  String className;
+  String? className;
 
   /// The package where the generated class will live.
-  String package;
+  String? package;
 }
 
 void _writeHostApi(Indent indent, Api api) {
@@ -198,7 +204,7 @@ String _makeSetter(Field field) {
   return 'set$uppercased';
 }
 
-String _javaTypeForDartType(String datatype) {
+String? _javaTypeForDartType(String datatype) {
   return _javaTypeForDartTypeMap[datatype];
 }
 
@@ -236,11 +242,10 @@ void generateJava(JavaOptions options, Root root, StringSink sink) {
   indent.writeln('import java.util.HashMap;');
 
   indent.addln('');
-  assert(options.className != null);
   indent.writeln('/** Generated class from Pigeon. */');
   indent.writeln(
       '@SuppressWarnings({"unused", "unchecked", "CodeBlock2Expr", "RedundantSuppression"})');
-  indent.write('public class ${options.className} ');
+  indent.write('public class ${options.className!} ');
   indent.scoped('{', '}', () {
     for (final Class klass in root.classes) {
       indent.addln('');
diff --git a/packages/pigeon/lib/objc_generator.dart b/packages/pigeon/lib/objc_generator.dart
index 30a4b59a8690..54665b825a35 100644
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@@ -8,17 +8,20 @@ import 'generator_tools.dart';
 /// Options that control how Objective-C code will be generated.
 class ObjcOptions {
   /// Parametric constructor for ObjcOptions.
-  ObjcOptions({this.header, this.prefix});
+  ObjcOptions({
+    this.header,
+    this.prefix,
+  });
 
   /// The path to the header that will get placed in the source filed (example:
   /// "foo.h").
-  String header;
+  String? header;
 
   /// Prefix that will be appended before all generated classes and protocols.
-  String prefix;
+  String? prefix;
 }
 
-String _className(String prefix, String className) {
+String _className(String? prefix, String className) {
   if (prefix != null) {
     return '$prefix$className';
   } else {
@@ -58,12 +61,12 @@ const Map<String, String> _propertyTypeForDartTypeMap = <String, String>{
   'Map': 'strong',
 };
 
-String _objcTypeForDartType(String type) {
+String? _objcTypeForDartType(String type) {
   return _objcTypeForDartTypeMap[type];
 }
 
 String _propertyTypeForDartType(String type) {
-  final String result = _propertyTypeForDartTypeMap[type];
+  final String? result = _propertyTypeForDartTypeMap[type];
   if (result == null) {
     return 'assign';
   } else {
@@ -72,7 +75,7 @@ String _propertyTypeForDartType(String type) {
 }
 
 void _writeClassDeclarations(
-    Indent indent, List<Class> classes, String prefix) {
+    Indent indent, List<Class> classes, String? prefix) {
   for (final Class klass in classes) {
     indent.writeln('@interface ${_className(prefix, klass.name)} : NSObject');
     for (final Field field in klass.fields) {
@@ -191,7 +194,7 @@ void generateObjcHeader(ObjcOptions options, Root root, StringSink sink) {
 }
 
 String _dictGetter(
-    List<String> classnames, String dict, Field field, String prefix) {
+    List<String> classnames, String dict, Field field, String? prefix) {
   if (classnames.contains(field.dataType)) {
     String className = field.dataType;
     if (prefix != null) {
diff --git a/packages/pigeon/lib/pigeon_cl.dart b/packages/pigeon/lib/pigeon_cl.dart
index b605d9d55fe3..de70005bfc5c 100644
--- a/packages/pigeon/lib/pigeon_cl.dart
+++ b/packages/pigeon/lib/pigeon_cl.dart
@@ -11,7 +11,7 @@ import 'package:pigeon/pigeon_lib.dart';
 
 /// This creates a relative path from `from` to `input`, the output being a
 /// posix path on all platforms.
-String _posixRelative(String input, {String from}) {
+String _posixRelative(String input, {required String from}) {
   final path.Context context = path.Context(style: path.Style.posix);
   final String rawInputPath = input;
   final String absInputPath = File(rawInputPath).absolute.path;
@@ -27,7 +27,7 @@ String _posixRelative(String input, {String from}) {
 /// This is the main entrypoint for the command-line tool.  [args] are the
 /// commmand line arguments and there is an optional [packageConfig] to
 /// accomodate users that want to integrate pigeon with other build systems.
-Future<void> runCommandLine(List<String> args, {Uri packageConfig}) async {
+Future<void> runCommandLine(List<String> args, {Uri? packageConfig}) async {
   final PigeonOptions opts = Pigeon.parseArgs(args);
   final Directory tempDir = Directory.systemTemp.createTempSync(
     'flutter_pigeon.',
@@ -35,11 +35,11 @@ Future<void> runCommandLine(List<String> args, {Uri packageConfig}) async {
 
   String importLine = '';
   if (opts.input != null) {
-    final String relInputPath = _posixRelative(opts.input, from: tempDir.path);
+    final String relInputPath = _posixRelative(opts.input!, from: tempDir.path);
     importLine = 'import \'$relInputPath\';\n';
   }
   final String code = """
-// @dart = 2.2
+// @dart = 2.12
 $importLine
 import 'dart:io';
 import 'dart:isolate';
diff --git a/packages/pigeon/lib/pigeon_lib.dart b/packages/pigeon/lib/pigeon_lib.dart
index 4072779440e1..9d3bc2ba35fe 100644
--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@@ -58,7 +58,7 @@ class HostApi {
   /// testing.
   ///
   /// Defaults to `null` in which case no handler will be generated.
-  final String dartHostTestHandler;
+  final String? dartHostTestHandler;
 }
 
 /// Metadata to annotate a Pigeon API implemented by Flutter.
@@ -75,16 +75,20 @@ class FlutterApi {
 /// Represents an error as a result of parsing and generating code.
 class Error {
   /// Parametric constructor for Error.
-  Error({this.message, this.filename, this.lineNumber});
+  Error({
+    required this.message,
+    this.filename,
+    this.lineNumber,
+  });
 
   /// A description of the error.
   String message;
 
   /// What file caused the [Error].
-  String filename;
+  String? filename;
 
   /// What line the error happened on.
-  int lineNumber;
+  int? lineNumber;
 
   @override
   String toString() {
@@ -97,7 +101,7 @@ bool _isApi(ClassMirror classMirror) {
       (_getHostApi(classMirror) != null || _isFlutterApi(classMirror));
 }
 
-HostApi _getHostApi(ClassMirror apiMirror) {
+HostApi? _getHostApi(ClassMirror apiMirror) {
   for (final InstanceMirror instance in apiMirror.metadata) {
     if (instance.reflectee is HostApi) {
       return instance.reflectee;
@@ -117,38 +121,44 @@ bool _isFlutterApi(ClassMirror apiMirror) {
 
 /// Options used when running the code generator.
 class PigeonOptions {
+  /// Creates a instance of PigeonOptions
+  PigeonOptions();
+
   /// Path to the file which will be processed.
-  String input;
+  String? input;
 
   /// Path to the dart file that will be generated.
-  String dartOut;
+  String? dartOut;
 
   /// Path to the dart file that will be generated for test support classes.
-  String dartTestOut;
+  String? dartTestOut;
 
   /// Path to the ".h" Objective-C file will be generated.
-  String objcHeaderOut;
+  String? objcHeaderOut;
 
   /// Path to the ".m" Objective-C file will be generated.
-  String objcSourceOut;
+  String? objcSourceOut;
 
   /// Options that control how Objective-C will be generated.
-  ObjcOptions objcOptions = ObjcOptions();
+  ObjcOptions? objcOptions;
 
   /// Path to the java file that will be generated.
-  String javaOut;
+  String? javaOut;
 
   /// Options that control how Java will be generated.
-  JavaOptions javaOptions = JavaOptions();
+  JavaOptions? javaOptions;
 
   /// Options that control how Dart will be generated.
-  DartOptions dartOptions = DartOptions();
+  DartOptions? dartOptions = DartOptions();
 }
 
 /// A collection of an AST represented as a [Root] and [Error]'s.
 class ParseResults {
   /// Parametric constructor for [ParseResults].
-  ParseResults({this.root, this.errors});
+  ParseResults({
+    required this.root,
+    required this.errors,
+  });
 
   /// The resulting AST.
   final Root root;
@@ -169,14 +179,18 @@ class Pigeon {
     for (final DeclarationMirror declaration
         in klassMirror.declarations.values) {
       if (declaration is VariableMirror) {
-        fields.add(Field()
-          ..name = MirrorSystem.getName(declaration.simpleName)
-          ..dataType = MirrorSystem.getName(declaration.type.simpleName));
+        fields.add(Field(
+          name: MirrorSystem.getName(declaration.simpleName),
+          dataType: MirrorSystem.getName(
+            declaration.type.simpleName,
+          ),
+        ));
       }
     }
-    final Class klass = Class()
-      ..name = MirrorSystem.getName(klassMirror.simpleName)
-      ..fields = fields;
+    final Class klass = Class(
+      name: MirrorSystem.getName(klassMirror.simpleName),
+      fields: fields,
+    );
     return klass;
   }
 
@@ -208,7 +222,6 @@ class Pigeon {
 
   /// Use reflection to parse the [types] provided.
   ParseResults parse(List<Type> types) {
-    final Root root = Root();
     final Set<ClassMirror> classes = <ClassMirror>{};
     final List<ClassMirror> apis = <ClassMirror>[];
 
@@ -226,19 +239,19 @@ class Pigeon {
           in apiMirror.declarations.values) {
         if (declaration is MethodMirror && !declaration.isConstructor) {
           if (!isVoid(declaration.returnType)) {
-            classes.add(declaration.returnType);
+            classes.add(declaration.returnType as ClassMirror);
           }
           if (declaration.parameters.isNotEmpty) {
-            classes.add(declaration.parameters[0].type);
+            classes.add(declaration.parameters[0].type as ClassMirror);
           }
         }
       }
     }
-
-    root.classes =
-        _unique(_parseClassMirrors(classes), (Class x) => x.name).toList();
-
-    root.apis = <Api>[];
+    final Root root = Root(
+      classes:
+          _unique(_parseClassMirrors(classes), (Class x) => x.name).toList(),
+      apis: <Api>[],
+    );
     for (final ClassMirror apiMirror in apis) {
       final List<Method> functions = <Method>[];
       for (final DeclarationMirror declaration
@@ -249,23 +262,24 @@ class Pigeon {
             return MirrorSystem.getName(it.type.simpleName) ==
                 '${async.runtimeType}';
           });
-          functions.add(Method()
-            ..name = MirrorSystem.getName(declaration.simpleName)
-            ..argType = declaration.parameters.isEmpty
+          functions.add(Method(
+            name: MirrorSystem.getName(declaration.simpleName),
+            argType: declaration.parameters.isEmpty
                 ? 'void'
                 : MirrorSystem.getName(
-                    declaration.parameters[0].type.simpleName)
-            ..returnType =
-                MirrorSystem.getName(declaration.returnType.simpleName)
-            ..isAsynchronous = isAsynchronous);
+                    declaration.parameters[0].type.simpleName),
+            returnType: MirrorSystem.getName(declaration.returnType.simpleName),
+            isAsynchronous: isAsynchronous,
+          ));
         }
       }
-      final HostApi hostApi = _getHostApi(apiMirror);
+      final HostApi? hostApi = _getHostApi(apiMirror);
       root.apis.add(Api(
-          name: MirrorSystem.getName(apiMirror.simpleName),
-          location: hostApi != null ? ApiLocation.host : ApiLocation.flutter,
-          methods: functions,
-          dartHostTestHandler: hostApi?.dartHostTestHandler));
+        name: MirrorSystem.getName(apiMirror.simpleName),
+        location: hostApi != null ? ApiLocation.host : ApiLocation.flutter,
+        methods: functions,
+        dartHostTestHandler: hostApi?.dartHostTestHandler,
+      ));
     }
 
     final List<Error> validateErrors = _validateAst(root);
@@ -315,10 +329,17 @@ options:
     opts.dartTestOut = results['dart_test_out'];
     opts.objcHeaderOut = results['objc_header_out'];
     opts.objcSourceOut = results['objc_source_out'];
-    opts.objcOptions.prefix = results['objc_prefix'];
+    opts.objcOptions = ObjcOptions(
+      prefix: results['objc_prefix'],
+    );
     opts.javaOut = results['java_out'];
-    opts.javaOptions.package = results['java_package'];
-    opts.dartOptions.isNullSafe = results['dart_null_safety'];
+    opts.javaOptions = JavaOptions(
+      className: (opts.javaOut == null)
+          ? null
+          : path.basenameWithoutExtension(opts.javaOut!),
+      package: results['java_package'],
+    );
+    opts.dartOptions = DartOptions()..isNullSafe = results['dart_null_safety'];
     return opts;
   }
 
@@ -408,10 +429,7 @@ options:
     final List<Error> errors = <Error>[];
     final List<Type> apis = <Type>[];
     if (options.objcHeaderOut != null) {
-      options.objcOptions.header = basename(options.objcHeaderOut);
-    }
-    if (options.javaOut != null) {
-      options.javaOptions.className = basenameWithoutExtension(options.javaOut);
+      options.objcOptions?.header = basename(options.objcHeaderOut!);
     }
 
     for (final LibraryMirror library
@@ -430,19 +448,19 @@ options:
       }
       if (options.dartOut != null) {
         await _runGenerator(
-            options.dartOut,
-            (StringSink sink) =>
-                generateDart(options.dartOptions, parseResults.root, sink));
+            options.dartOut!,
+            (StringSink sink) => generateDart(
+                options.dartOptions ?? DartOptions(), parseResults.root, sink));
       }
-      if (options.dartTestOut != null) {
+      if (options.dartTestOut != null && options.dartOut != null) {
         final String mainPath = context.relative(
-          _posixify(options.dartOut),
-          from: _posixify(path.dirname(options.dartTestOut)),
+          _posixify(options.dartOut!),
+          from: _posixify(path.dirname(options.dartTestOut!)),
         );
         await _runGenerator(
-          options.dartTestOut,
+          options.dartTestOut!,
           (StringSink sink) => generateTestDart(
-            options.dartOptions,
+            options.dartOptions ?? DartOptions(),
             parseResults.root,
             sink,
             mainPath,
@@ -451,21 +469,21 @@ options:
       }
       if (options.objcHeaderOut != null) {
         await _runGenerator(
-            options.objcHeaderOut,
+            options.objcHeaderOut!,
             (StringSink sink) => generateObjcHeader(
-                options.objcOptions, parseResults.root, sink));
+                options.objcOptions ?? ObjcOptions(), parseResults.root, sink));
       }
       if (options.objcSourceOut != null) {
         await _runGenerator(
-            options.objcSourceOut,
+            options.objcSourceOut!,
             (StringSink sink) => generateObjcSource(
-                options.objcOptions, parseResults.root, sink));
+                options.objcOptions ?? ObjcOptions(), parseResults.root, sink));
       }
       if (options.javaOut != null) {
         await _runGenerator(
-            options.javaOut,
-            (StringSink sink) =>
-                generateJava(options.javaOptions, parseResults.root, sink));
+            options.javaOut!,
+            (StringSink sink) => generateJava(
+                options.javaOptions ?? JavaOptions(), parseResults.root, sink));
       }
     } else {
       errors.add(Error(message: 'No pigeon classes found, nothing generated.'));
diff --git a/packages/pigeon/mock_handler_tester/pubspec.yaml b/packages/pigeon/mock_handler_tester/pubspec.yaml
index eeabf8d49fd0..1826c25edda6 100644
--- a/packages/pigeon/mock_handler_tester/pubspec.yaml
+++ b/packages/pigeon/mock_handler_tester/pubspec.yaml
@@ -4,10 +4,10 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.7.0 <3.0.0"
+  sdk: ">=2.12.0 <3.0.0"
 
 dependencies:
-  cupertino_icons: ^0.1.3
+  cupertino_icons: ^1.0.2
   flutter:
     sdk: flutter
 
diff --git a/packages/pigeon/mock_handler_tester/test/message.dart b/packages/pigeon/mock_handler_tester/test/message.dart
index 30ccafa5a4ac..0896b04a9cd3 100644
--- a/packages/pigeon/mock_handler_tester/test/message.dart
+++ b/packages/pigeon/mock_handler_tester/test/message.dart
@@ -1,38 +1,38 @@
-// Autogenerated from Pigeon (v0.1.19), do not edit directly.
+// Autogenerated from Pigeon (v0.2.0-nullsafety.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import
-// @dart = 2.8
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types
+// @dart = 2.12
 import 'dart:async';
 import 'dart:typed_data' show Uint8List, Int32List, Int64List, Float64List;
 
 import 'package:flutter/services.dart';
 
 class SearchReply {
-  String result;
-  String error;
+  String? result;
+  String? error;
 
   Object encode() {
-    final Map<Object, Object> pigeonMap = <Object, Object>{};
+    final Map<Object?, Object?> pigeonMap = <Object?, Object?>{};
     pigeonMap['result'] = result;
     pigeonMap['error'] = error;
     return pigeonMap;
   }
 
   static SearchReply decode(Object message) {
-    final Map<Object, Object> pigeonMap = message as Map<Object, Object>;
+    final Map<Object?, Object?> pigeonMap = message as Map<Object?, Object?>;
     return SearchReply()
-      ..result = pigeonMap['result'] as String
-      ..error = pigeonMap['error'] as String;
+      ..result = pigeonMap['result'] as String?
+      ..error = pigeonMap['error'] as String?;
   }
 }
 
 class SearchRequest {
-  String query;
-  int anInt;
-  bool aBool;
+  String? query;
+  int? anInt;
+  bool? aBool;
 
   Object encode() {
-    final Map<Object, Object> pigeonMap = <Object, Object>{};
+    final Map<Object?, Object?> pigeonMap = <Object?, Object?>{};
     pigeonMap['query'] = query;
     pigeonMap['anInt'] = anInt;
     pigeonMap['aBool'] = aBool;
@@ -40,45 +40,45 @@ class SearchRequest {
   }
 
   static SearchRequest decode(Object message) {
-    final Map<Object, Object> pigeonMap = message as Map<Object, Object>;
+    final Map<Object?, Object?> pigeonMap = message as Map<Object?, Object?>;
     return SearchRequest()
-      ..query = pigeonMap['query'] as String
-      ..anInt = pigeonMap['anInt'] as int
-      ..aBool = pigeonMap['aBool'] as bool;
+      ..query = pigeonMap['query'] as String?
+      ..anInt = pigeonMap['anInt'] as int?
+      ..aBool = pigeonMap['aBool'] as bool?;
   }
 }
 
 class Nested {
-  SearchRequest request;
+  SearchRequest? request;
 
   Object encode() {
-    final Map<Object, Object> pigeonMap = <Object, Object>{};
-    pigeonMap['request'] = request?.encode();
+    final Map<Object?, Object?> pigeonMap = <Object?, Object?>{};
+    pigeonMap['request'] = request == null ? null : request!.encode();
     return pigeonMap;
   }
 
   static Nested decode(Object message) {
-    final Map<Object, Object> pigeonMap = message as Map<Object, Object>;
+    final Map<Object?, Object?> pigeonMap = message as Map<Object?, Object?>;
     return Nested()
       ..request = pigeonMap['request'] != null
-          ? SearchRequest.decode(pigeonMap['request'])
+          ? SearchRequest.decode(pigeonMap['request']!)
           : null;
   }
 }
 
 abstract class FlutterSearchApi {
   SearchReply search(SearchRequest arg);
-  static void setup(FlutterSearchApi api) {
+  static void setup(FlutterSearchApi? api) {
     {
-      const BasicMessageChannel<Object> channel = BasicMessageChannel<Object>(
+      const BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
           'dev.flutter.pigeon.FlutterSearchApi.search', StandardMessageCodec());
       if (api == null) {
         channel.setMessageHandler(null);
       } else {
-        channel.setMessageHandler((Object message) async {
+        channel.setMessageHandler((Object? message) async {
           assert(message != null,
               'Argument for dev.flutter.pigeon.FlutterSearchApi.search was null. Expected SearchRequest.');
-          final SearchRequest input = SearchRequest.decode(message);
+          final SearchRequest input = SearchRequest.decode(message!);
           final SearchReply output = api.search(input);
           return output.encode();
         });
@@ -90,10 +90,10 @@ abstract class FlutterSearchApi {
 class NestedApi {
   Future<SearchReply> search(Nested arg) async {
     final Object encoded = arg.encode();
-    const BasicMessageChannel<Object> channel = BasicMessageChannel<Object>(
+    const BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
         'dev.flutter.pigeon.NestedApi.search', StandardMessageCodec());
-    final Map<Object, Object> replyMap =
-        await channel.send(encoded) as Map<Object, Object>;
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(encoded) as Map<Object?, Object?>?;
     if (replyMap == null) {
       throw PlatformException(
         code: 'channel-error',
@@ -101,25 +101,25 @@ class NestedApi {
         details: null,
       );
     } else if (replyMap['error'] != null) {
-      final Map<Object, Object> error =
-          replyMap['error'] as Map<Object, Object>;
+      final Map<Object?, Object?> error =
+          (replyMap['error'] as Map<Object?, Object?>?)!;
       throw PlatformException(
-        code: error['code'] as String,
-        message: error['message'] as String,
+        code: (error['code'] as String?)!,
+        message: error['message'] as String?,
         details: error['details'],
       );
     } else {
-      return SearchReply.decode(replyMap['result']);
+      return SearchReply.decode(replyMap['result']!);
     }
   }
 }
 
 class Api {
   Future<void> initialize() async {
-    const BasicMessageChannel<Object> channel = BasicMessageChannel<Object>(
+    const BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
         'dev.flutter.pigeon.Api.initialize', StandardMessageCodec());
-    final Map<Object, Object> replyMap =
-        await channel.send(null) as Map<Object, Object>;
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(null) as Map<Object?, Object?>?;
     if (replyMap == null) {
       throw PlatformException(
         code: 'channel-error',
@@ -127,11 +127,11 @@ class Api {
         details: null,
       );
     } else if (replyMap['error'] != null) {
-      final Map<Object, Object> error =
-          replyMap['error'] as Map<Object, Object>;
+      final Map<Object?, Object?> error =
+          (replyMap['error'] as Map<Object?, Object?>?)!;
       throw PlatformException(
-        code: error['code'] as String,
-        message: error['message'] as String,
+        code: (error['code'] as String?)!,
+        message: error['message'] as String?,
         details: error['details'],
       );
     } else {
@@ -141,10 +141,10 @@ class Api {
 
   Future<SearchReply> search(SearchRequest arg) async {
     final Object encoded = arg.encode();
-    const BasicMessageChannel<Object> channel = BasicMessageChannel<Object>(
+    const BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
         'dev.flutter.pigeon.Api.search', StandardMessageCodec());
-    final Map<Object, Object> replyMap =
-        await channel.send(encoded) as Map<Object, Object>;
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(encoded) as Map<Object?, Object?>?;
     if (replyMap == null) {
       throw PlatformException(
         code: 'channel-error',
@@ -152,15 +152,15 @@ class Api {
         details: null,
       );
     } else if (replyMap['error'] != null) {
-      final Map<Object, Object> error =
-          replyMap['error'] as Map<Object, Object>;
+      final Map<Object?, Object?> error =
+          (replyMap['error'] as Map<Object?, Object?>?)!;
       throw PlatformException(
-        code: error['code'] as String,
-        message: error['message'] as String,
+        code: (error['code'] as String?)!,
+        message: error['message'] as String?,
         details: error['details'],
       );
     } else {
-      return SearchReply.decode(replyMap['result']);
+      return SearchReply.decode(replyMap['result']!);
     }
   }
 }
diff --git a/packages/pigeon/mock_handler_tester/test/test.dart b/packages/pigeon/mock_handler_tester/test/test.dart
index 7c6ccf03de37..0d8e4c3ad52c 100644
--- a/packages/pigeon/mock_handler_tester/test/test.dart
+++ b/packages/pigeon/mock_handler_tester/test/test.dart
@@ -1,7 +1,7 @@
-// Autogenerated from Pigeon (v0.1.19), do not edit directly.
+// Autogenerated from Pigeon (v0.2.0-nullsafety.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import
-// @dart = 2.8
+// @dart = 2.12
 import 'dart:async';
 import 'dart:typed_data' show Uint8List, Int32List, Int64List, Float64List;
 import 'package:flutter/services.dart';
@@ -11,19 +11,19 @@ import 'message.dart';
 
 abstract class TestNestedApi {
   SearchReply search(Nested arg);
-  static void setup(TestNestedApi api) {
+  static void setup(TestNestedApi? api) {
     {
-      const BasicMessageChannel<Object> channel = BasicMessageChannel<Object>(
+      const BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
           'dev.flutter.pigeon.NestedApi.search', StandardMessageCodec());
       if (api == null) {
         channel.setMockMessageHandler(null);
       } else {
-        channel.setMockMessageHandler((Object message) async {
+        channel.setMockMessageHandler((Object? message) async {
           assert(message != null,
               'Argument for dev.flutter.pigeon.NestedApi.search was null. Expected Nested.');
-          final Nested input = Nested.decode(message);
+          final Nested input = Nested.decode(message!);
           final SearchReply output = api.search(input);
-          return <Object, Object>{'result': output.encode()};
+          return <Object?, Object?>{'result': output.encode()};
         });
       }
     }
@@ -33,32 +33,32 @@ abstract class TestNestedApi {
 abstract class TestHostApi {
   void initialize();
   SearchReply search(SearchRequest arg);
-  static void setup(TestHostApi api) {
+  static void setup(TestHostApi? api) {
     {
-      const BasicMessageChannel<Object> channel = BasicMessageChannel<Object>(
+      const BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
           'dev.flutter.pigeon.Api.initialize', StandardMessageCodec());
       if (api == null) {
         channel.setMockMessageHandler(null);
       } else {
-        channel.setMockMessageHandler((Object message) async {
+        channel.setMockMessageHandler((Object? message) async {
           // ignore message
           api.initialize();
-          return <Object, Object>{};
+          return <Object?, Object?>{};
         });
       }
     }
     {
-      const BasicMessageChannel<Object> channel = BasicMessageChannel<Object>(
+      const BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
           'dev.flutter.pigeon.Api.search', StandardMessageCodec());
       if (api == null) {
         channel.setMockMessageHandler(null);
       } else {
-        channel.setMockMessageHandler((Object message) async {
+        channel.setMockMessageHandler((Object? message) async {
           assert(message != null,
               'Argument for dev.flutter.pigeon.Api.search was null. Expected SearchRequest.');
-          final SearchRequest input = SearchRequest.decode(message);
+          final SearchRequest input = SearchRequest.decode(message!);
           final SearchReply output = api.search(input);
-          return <Object, Object>{'result': output.encode()};
+          return <Object?, Object?>{'result': output.encode()};
         });
       }
     }
diff --git a/packages/pigeon/mock_handler_tester/test/widget_test.dart b/packages/pigeon/mock_handler_tester/test/widget_test.dart
index 4f6497c45b15..0334051cad4f 100644
--- a/packages/pigeon/mock_handler_tester/test/widget_test.dart
+++ b/packages/pigeon/mock_handler_tester/test/widget_test.dart
@@ -33,7 +33,7 @@ class MockNested implements TestNestedApi {
     if (arg.request == null) {
       return SearchReply();
     } else {
-      return SearchReply()..result = arg.request.query;
+      return SearchReply()..result = arg.request?.query;
     }
   }
 }
@@ -73,17 +73,17 @@ void main() {
       final Mock mock = Mock();
       TestHostApi.setup(mock);
       expect(
-        await const BasicMessageChannel<Object>(
+        await const BasicMessageChannel<Object?>(
           'dev.flutter.pigeon.Api.initialize',
           StandardMessageCodec(),
         ).send(null),
         isEmpty,
       );
       try {
-        await const BasicMessageChannel<Object>(
+        await const BasicMessageChannel<Object?>(
           'dev.flutter.pigeon.Api.search',
           StandardMessageCodec(),
-        ).send(null) as Map<Object, Object>;
+        ).send(null) as Map<Object?, Object?>?;
         expect(true, isFalse); // should not reach here
       } catch (error) {
         expect(error, isAssertionError);
diff --git a/packages/pigeon/pigeons/all_datatypes.dart b/packages/pigeon/pigeons/all_datatypes.dart
index 981f87cc10be..95a28863bc02 100644
--- a/packages/pigeon/pigeons/all_datatypes.dart
+++ b/packages/pigeon/pigeons/all_datatypes.dart
@@ -5,18 +5,18 @@
 import 'package:pigeon/pigeon.dart';
 
 class Everything {
-  bool aBool;
-  int anInt;
-  double aDouble;
-  String aString;
-  Uint8List aByteArray;
-  Int32List a4ByteArray;
-  Int64List a8ByteArray;
-  Float64List aFloatArray;
+  bool? aBool;
+  int? anInt;
+  double? aDouble;
+  String? aString;
+  Uint8List? aByteArray;
+  Int32List? a4ByteArray;
+  Int64List? a8ByteArray;
+  Float64List? aFloatArray;
   // ignore: always_specify_types
-  List aList;
+  List? aList;
   // ignore: always_specify_types
-  Map aMap;
+  Map? aMap;
 }
 
 @HostApi()
diff --git a/packages/pigeon/pigeons/async_handlers.dart b/packages/pigeon/pigeons/async_handlers.dart
index 8e86671ba4f4..67c439e7ae3a 100644
--- a/packages/pigeon/pigeons/async_handlers.dart
+++ b/packages/pigeon/pigeons/async_handlers.dart
@@ -5,7 +5,7 @@
 import 'package:pigeon/pigeon.dart';
 
 class Value {
-  int number;
+  int? number;
 }
 
 @HostApi()
diff --git a/packages/pigeon/pigeons/host2flutter.dart b/packages/pigeon/pigeons/host2flutter.dart
index 673ff56334f9..5a45975778b6 100644
--- a/packages/pigeon/pigeons/host2flutter.dart
+++ b/packages/pigeon/pigeons/host2flutter.dart
@@ -2,14 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'package:pigeon/objc_generator.dart';
 import 'package:pigeon/pigeon.dart';
 
 class SearchRequest {
-  String query;
+  String? query;
 }
 
 class SearchReply {
-  String result;
+  String? result;
 }
 
 @FlutterApi()
@@ -18,5 +19,6 @@ abstract class Api {
 }
 
 void configurePigeon(PigeonOptions options) {
-  options.objcOptions.prefix = 'AC';
+  options.objcOptions ??= ObjcOptions();
+  options.objcOptions?.prefix = 'AC';
 }
diff --git a/packages/pigeon/pigeons/list.dart b/packages/pigeon/pigeons/list.dart
index bed4a79227b9..e370ae80120c 100644
--- a/packages/pigeon/pigeons/list.dart
+++ b/packages/pigeon/pigeons/list.dart
@@ -6,7 +6,7 @@ import 'package:pigeon/pigeon.dart';
 
 class TestMessage {
   // ignore: always_specify_types
-  List testList;
+  List? testList;
 }
 
 @HostApi()
diff --git a/packages/pigeon/pigeons/message.dart b/packages/pigeon/pigeons/message.dart
index 02b95840f638..449debff2fee 100644
--- a/packages/pigeon/pigeons/message.dart
+++ b/packages/pigeon/pigeons/message.dart
@@ -5,17 +5,19 @@
 // This file is an example pigeon file that is used in compilation, unit, mock
 // handler, and e2e tests.
 
+import 'package:pigeon/java_generator.dart';
+import 'package:pigeon/objc_generator.dart';
 import 'package:pigeon/pigeon.dart';
 
 class SearchRequest {
-  String query;
-  int anInt;
-  bool aBool;
+  String? query;
+  int? anInt;
+  bool? aBool;
 }
 
 class SearchReply {
-  String result;
-  String error;
+  String? result;
+  String? error;
 }
 
 @HostApi(dartHostTestHandler: 'TestHostApi')
@@ -25,7 +27,7 @@ abstract class Api {
 }
 
 class Nested {
-  SearchRequest request;
+  SearchRequest? request;
 }
 
 @HostApi(dartHostTestHandler: 'TestNestedApi')
@@ -34,8 +36,10 @@ abstract class NestedApi {
 }
 
 void configurePigeon(PigeonOptions options) {
-  options.objcOptions.prefix = 'AC';
-  options.javaOptions.package = 'dev.flutter.aaclarke.pigeon';
+  options.objcOptions ??= ObjcOptions();
+  options.objcOptions?.prefix = 'AC';
+  options.javaOptions ??= JavaOptions(className: 'Pigeon');
+  options.javaOptions?.package = 'dev.flutter.aaclarke.pigeon';
 }
 
 @FlutterApi()
diff --git a/packages/pigeon/pigeons/void_arg_flutter.dart b/packages/pigeon/pigeons/void_arg_flutter.dart
index 9886e0e10c0b..d6fbd5490865 100644
--- a/packages/pigeon/pigeons/void_arg_flutter.dart
+++ b/packages/pigeon/pigeons/void_arg_flutter.dart
@@ -5,7 +5,7 @@
 import 'package:pigeon/pigeon.dart';
 
 class Result {
-  int code;
+  int? code;
 }
 
 @FlutterApi()
diff --git a/packages/pigeon/pigeons/void_arg_host.dart b/packages/pigeon/pigeons/void_arg_host.dart
index 38229a08fa70..fec04ab930ea 100644
--- a/packages/pigeon/pigeons/void_arg_host.dart
+++ b/packages/pigeon/pigeons/void_arg_host.dart
@@ -5,7 +5,7 @@
 import 'package:pigeon/pigeon.dart';
 
 class Result {
-  int code;
+  int? code;
 }
 
 @HostApi()
diff --git a/packages/pigeon/pigeons/voidflutter.dart b/packages/pigeon/pigeons/voidflutter.dart
index 9606c210e8af..eb2faa946654 100644
--- a/packages/pigeon/pigeons/voidflutter.dart
+++ b/packages/pigeon/pigeons/voidflutter.dart
@@ -5,7 +5,7 @@
 import 'package:pigeon/pigeon.dart';
 
 class SetRequest {
-  int value;
+  int? value;
 }
 
 @FlutterApi()
diff --git a/packages/pigeon/pigeons/voidhost.dart b/packages/pigeon/pigeons/voidhost.dart
index ffd7f01c4db0..cdbbebda8d38 100644
--- a/packages/pigeon/pigeons/voidhost.dart
+++ b/packages/pigeon/pigeons/voidhost.dart
@@ -5,7 +5,7 @@
 import 'package:pigeon/pigeon.dart';
 
 class SetRequest {
-  int value;
+  int? value;
 }
 
 @HostApi()
diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index 13a236945805..8d041a398865 100644
--- a/packages/pigeon/pubspec.yaml
+++ b/packages/pigeon/pubspec.yaml
@@ -1,11 +1,11 @@
 name: pigeon
-version: 0.1.24 # This must match the version in lib/generator_tools.dart
+version: 0.2.0 # This must match the version in lib/generator_tools.dart
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 homepage: https://github.com/flutter/packages/tree/master/packages/pigeon
 dependencies:
-  args: ^1.5.2
-  path: ^1.6.4
+  args: ^2.0.0
+  path: ^1.8.0
 dev_dependencies:
   test: ^1.11.1
 environment:
-  sdk: '>=2.2.0 <3.0.0'
+  sdk: '>=2.12.0 <3.0.0'
diff --git a/packages/pigeon/run_tests.sh b/packages/pigeon/run_tests.sh
index f370651fe812..ab4610e38d10 100755
--- a/packages/pigeon/run_tests.sh
+++ b/packages/pigeon/run_tests.sh
@@ -80,6 +80,7 @@ test_pigeon_android() {
 
   pub run pigeon \
     --input $1 \
+    --dart_null_safety \
     --dart_out $temp_dir/pigeon.dart \
     --java_out $temp_dir/Pigeon.java \
     --java_package foo
@@ -151,7 +152,7 @@ fi
 pub get
 dart analyze bin
 dart analyze lib
-dart --no-sound-null-safety test
+dart test
 
 ###############################################################################
 # Execute without arguments test
@@ -177,6 +178,7 @@ popd
 pushd $PWD
 pub run pigeon \
   --input pigeons/message.dart \
+  --dart_null_safety \
   --dart_out mock_handler_tester/test/message.dart \
   --dart_test_out mock_handler_tester/test/test.dart
 dartfmt -w mock_handler_tester/test/message.dart
@@ -253,6 +255,7 @@ DARTLE_DART="e2e_tests/test_objc/lib/dartle.dart"
 PIGEON_JAVA="e2e_tests/test_objc/android/app/src/main/java/io/flutter/plugins/Pigeon.java"
 pub run pigeon \
   --input pigeons/message.dart \
+  --dart_null_safety \
   --dart_out $DARTLE_DART \
   --objc_header_out $DARTLE_H \
   --objc_source_out $DARTLE_M \
diff --git a/packages/pigeon/test/dart_generator_test.dart b/packages/pigeon/test/dart_generator_test.dart
index 4f6fde4b71d0..6ef917238c9b 100644
--- a/packages/pigeon/test/dart_generator_test.dart
+++ b/packages/pigeon/test/dart_generator_test.dart
@@ -9,16 +9,19 @@ import 'package:test/test.dart';
 
 void main() {
   test('gen one class', () {
-    final Class klass = Class()
-      ..name = 'Foobar'
-      ..fields = <Field>[
-        Field()
-          ..name = 'field1'
-          ..dataType = 'dataType1'
-      ];
-    final Root root = Root()
-      ..apis = <Api>[]
-      ..classes = <Class>[klass];
+    final Class klass = Class(
+      name: 'Foobar',
+      fields: <Field>[
+        Field(
+          name: 'field1',
+          dataType: 'dataType1',
+        ),
+      ],
+    );
+    final Root root = Root(
+      apis: <Api>[],
+      classes: <Class>[klass],
+    );
     final StringBuffer sink = StringBuffer();
     generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
@@ -72,7 +75,7 @@ void main() {
       ),
     );
     expect(
-      code,
+      code.replaceAll('\n', ' ').replaceAll('  ', ''),
       contains(
         '..nested = pigeonMap[\'nested\'] != null ? Input.decode(pigeonMap[\'nested\']) : null;',
       ),
@@ -244,16 +247,19 @@ void main() {
   });
 
   test('opt out of nndb', () {
-    final Class klass = Class()
-      ..name = 'Foobar'
-      ..fields = <Field>[
-        Field()
-          ..name = 'field1'
-          ..dataType = 'dataType1'
-      ];
-    final Root root = Root()
-      ..apis = <Api>[]
-      ..classes = <Class>[klass];
+    final Class klass = Class(
+      name: 'Foobar',
+      fields: <Field>[
+        Field(
+          name: 'field1',
+          dataType: 'dataType1',
+        ),
+      ],
+    );
+    final Root root = Root(
+      apis: <Api>[],
+      classes: <Class>[klass],
+    );
     final StringBuffer sink = StringBuffer();
     generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
diff --git a/packages/pigeon/test/java_generator_test.dart b/packages/pigeon/test/java_generator_test.dart
index 398ca69ce05a..053049b3636a 100644
--- a/packages/pigeon/test/java_generator_test.dart
+++ b/packages/pigeon/test/java_generator_test.dart
@@ -8,19 +8,21 @@ import 'package:test/test.dart';
 
 void main() {
   test('gen one class', () {
-    final Class klass = Class()
-      ..name = 'Foobar'
-      ..fields = <Field>[
-        Field()
-          ..name = 'field1'
-          ..dataType = 'int'
-      ];
-    final Root root = Root()
-      ..apis = <Api>[]
-      ..classes = <Class>[klass];
+    final Class klass = Class(
+      name: 'Foobar',
+      fields: <Field>[
+        Field(
+          name: 'field1',
+          dataType: 'int',
+        ),
+      ],
+    );
+    final Root root = Root(
+      apis: <Api>[],
+      classes: <Class>[klass],
+    );
     final StringBuffer sink = StringBuffer();
-    final JavaOptions javaOptions = JavaOptions();
-    javaOptions.className = 'Messages';
+    final JavaOptions javaOptions = JavaOptions(className: 'Messages');
     generateJava(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public class Messages'));
@@ -29,20 +31,22 @@ void main() {
   });
 
   test('package', () {
-    final Class klass = Class()
-      ..name = 'Foobar'
-      ..fields = <Field>[
-        Field()
-          ..name = 'field1'
-          ..dataType = 'int'
-      ];
-    final Root root = Root()
-      ..apis = <Api>[]
-      ..classes = <Class>[klass];
+    final Class klass = Class(
+      name: 'Foobar',
+      fields: <Field>[
+        Field(
+          name: 'field1',
+          dataType: 'int',
+        )
+      ],
+    );
+    final Root root = Root(
+      apis: <Api>[],
+      classes: <Class>[klass],
+    );
     final StringBuffer sink = StringBuffer();
-    final JavaOptions javaOptions = JavaOptions();
-    javaOptions.className = 'Messages';
-    javaOptions.package = 'com.google.foobar';
+    final JavaOptions javaOptions = JavaOptions(className: 'Messages')
+      ..package = 'com.google.foobar';
     generateJava(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('package com.google.foobar;'));
@@ -68,8 +72,7 @@ void main() {
           fields: <Field>[Field(name: 'output', dataType: 'String')])
     ]);
     final StringBuffer sink = StringBuffer();
-    final JavaOptions javaOptions = JavaOptions();
-    javaOptions.className = 'Messages';
+    final JavaOptions javaOptions = JavaOptions(className: 'Messages');
     generateJava(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public interface Api'));
@@ -92,8 +95,7 @@ void main() {
     ]);
 
     final StringBuffer sink = StringBuffer();
-    final JavaOptions javaOptions = JavaOptions();
-    javaOptions.className = 'Messages';
+    final JavaOptions javaOptions = JavaOptions(className: 'Messages');
     generateJava(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('private Boolean aBool;'));
@@ -125,8 +127,7 @@ void main() {
           fields: <Field>[Field(name: 'output', dataType: 'String')])
     ]);
     final StringBuffer sink = StringBuffer();
-    final JavaOptions javaOptions = JavaOptions();
-    javaOptions.className = 'Messages';
+    final JavaOptions javaOptions = JavaOptions(className: 'Messages');
     generateJava(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public static class Api'));
@@ -149,8 +150,7 @@ void main() {
           fields: <Field>[Field(name: 'input', dataType: 'String')]),
     ]);
     final StringBuffer sink = StringBuffer();
-    final JavaOptions javaOptions = JavaOptions();
-    javaOptions.className = 'Messages';
+    final JavaOptions javaOptions = JavaOptions(className: 'Messages');
     generateJava(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, isNot(matches('=.*doSomething')));
@@ -173,8 +173,7 @@ void main() {
           fields: <Field>[Field(name: 'input', dataType: 'String')]),
     ]);
     final StringBuffer sink = StringBuffer();
-    final JavaOptions javaOptions = JavaOptions();
-    javaOptions.className = 'Messages';
+    final JavaOptions javaOptions = JavaOptions(className: 'Messages');
     generateJava(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('Reply<Void>'));
@@ -198,8 +197,7 @@ void main() {
           fields: <Field>[Field(name: 'output', dataType: 'String')]),
     ]);
     final StringBuffer sink = StringBuffer();
-    final JavaOptions javaOptions = JavaOptions();
-    javaOptions.className = 'Messages';
+    final JavaOptions javaOptions = JavaOptions(className: 'Messages');
     generateJava(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('Output doSomething()'));
@@ -222,8 +220,7 @@ void main() {
           fields: <Field>[Field(name: 'output', dataType: 'String')]),
     ]);
     final StringBuffer sink = StringBuffer();
-    final JavaOptions javaOptions = JavaOptions();
-    javaOptions.className = 'Messages';
+    final JavaOptions javaOptions = JavaOptions(className: 'Messages');
     generateJava(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('doSomething(Reply<Output>'));
@@ -237,8 +234,7 @@ void main() {
           fields: <Field>[Field(name: 'field1', dataType: 'List')]),
     ]);
     final StringBuffer sink = StringBuffer();
-    final JavaOptions javaOptions = JavaOptions();
-    javaOptions.className = 'Messages';
+    final JavaOptions javaOptions = JavaOptions(className: 'Messages');
     generateJava(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public static class Foobar'));
@@ -252,8 +248,7 @@ void main() {
           fields: <Field>[Field(name: 'field1', dataType: 'Map')]),
     ]);
     final StringBuffer sink = StringBuffer();
-    final JavaOptions javaOptions = JavaOptions();
-    javaOptions.className = 'Messages';
+    final JavaOptions javaOptions = JavaOptions(className: 'Messages');
     generateJava(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public static class Foobar'));
@@ -261,26 +256,30 @@ void main() {
   });
 
   test('gen nested', () {
-    final Class klass = Class()
-      ..name = 'Outer'
-      ..fields = <Field>[
-        Field()
-          ..name = 'nested'
-          ..dataType = 'Nested'
-      ];
-    final Class nestedClass = Class()
-      ..name = 'Nested'
-      ..fields = <Field>[
-        Field()
-          ..name = 'data'
-          ..dataType = 'int'
-      ];
-    final Root root = Root()
-      ..apis = <Api>[]
-      ..classes = <Class>[klass, nestedClass];
+    final Class klass = Class(
+      name: 'Outer',
+      fields: <Field>[
+        Field(
+          name: 'nested',
+          dataType: 'Nested',
+        )
+      ],
+    );
+    final Class nestedClass = Class(
+      name: 'Nested',
+      fields: <Field>[
+        Field(
+          name: 'data',
+          dataType: 'int',
+        )
+      ],
+    );
+    final Root root = Root(
+      apis: <Api>[],
+      classes: <Class>[klass, nestedClass],
+    );
     final StringBuffer sink = StringBuffer();
-    final JavaOptions javaOptions = JavaOptions();
-    javaOptions.className = 'Messages';
+    final JavaOptions javaOptions = JavaOptions(className: 'Messages');
     generateJava(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public class Messages'));
@@ -310,8 +309,7 @@ void main() {
           fields: <Field>[Field(name: 'output', dataType: 'String')])
     ]);
     final StringBuffer sink = StringBuffer();
-    final JavaOptions javaOptions = JavaOptions();
-    javaOptions.className = 'Messages';
+    final JavaOptions javaOptions = JavaOptions(className: 'Messages');
     generateJava(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public interface Api'));
@@ -344,8 +342,7 @@ void main() {
           fields: <Field>[Field(name: 'output', dataType: 'String')])
     ]);
     final StringBuffer sink = StringBuffer();
-    final JavaOptions javaOptions = JavaOptions();
-    javaOptions.className = 'Messages';
+    final JavaOptions javaOptions = JavaOptions(className: 'Messages');
     generateJava(javaOptions, root, sink);
     final String code = sink.toString();
     expect(code, contains('public static class Api'));
diff --git a/packages/pigeon/test/pigeon_lib_test.dart b/packages/pigeon/test/pigeon_lib_test.dart
index 1ae31471614f..f92117d2eb60 100644
--- a/packages/pigeon/test/pigeon_lib_test.dart
+++ b/packages/pigeon/test/pigeon_lib_test.dart
@@ -7,11 +7,11 @@ import 'package:pigeon/pigeon_lib.dart';
 import 'package:pigeon/ast.dart';
 
 class Input1 {
-  String input;
+  String? input;
 }
 
 class Output1 {
-  String output;
+  String? output;
 }
 
 @HostApi()
@@ -30,7 +30,7 @@ abstract class ApiTwoMethods {
 }
 
 class Nested {
-  Input1 input;
+  Input1? input;
 }
 
 @FlutterApi()
@@ -54,11 +54,11 @@ abstract class ApiWithMockDartClass {
 }
 
 class OnlyVisibleFromNesting {
-  String foo;
+  String? foo;
 }
 
 class Nestor {
-  OnlyVisibleFromNesting nested;
+  OnlyVisibleFromNesting? nested;
 }
 
 @HostApi()
@@ -92,7 +92,7 @@ void main() {
   test('parse args - java_package', () {
     final PigeonOptions opts =
         Pigeon.parseArgs(<String>['--java_package', 'com.google.foo']);
-    expect(opts.javaOptions.package, equals('com.google.foo'));
+    expect(opts.javaOptions?.package, equals('com.google.foo'));
   });
 
   test('parse args - input', () {
@@ -126,8 +126,8 @@ void main() {
     expect(root.apis[0].methods[0].argType, equals('Input1'));
     expect(root.apis[0].methods[0].returnType, equals('Output1'));
 
-    Class input;
-    Class output;
+    Class? input;
+    Class? output;
     for (final Class klass in root.classes) {
       if (klass.name == 'Input1') {
         input = klass;
@@ -138,13 +138,13 @@ void main() {
     expect(input, isNotNull);
     expect(output, isNotNull);
 
-    expect(input.fields.length, equals(1));
-    expect(input.fields[0].name, equals('input'));
-    expect(input.fields[0].dataType, equals('String'));
+    expect(input?.fields.length, equals(1));
+    expect(input?.fields[0].name, equals('input'));
+    expect(input?.fields[0].dataType, equals('String'));
 
-    expect(output.fields.length, equals(1));
-    expect(output.fields[0].name, equals('output'));
-    expect(output.fields[0].dataType, equals('String'));
+    expect(output?.fields.length, equals(1));
+    expect(output?.fields[0].name, equals('output'));
+    expect(output?.fields[0].dataType, equals('String'));
   });
 
   test('invalid datatype', () {
@@ -241,6 +241,6 @@ void main() {
   test('null safety flag', () {
     final PigeonOptions results =
         Pigeon.parseArgs(<String>['--dart_null_safety']);
-    expect(results.dartOptions.isNullSafe, true);
+    expect(results.dartOptions?.isNullSafe, isTrue);
   });
 }
diff --git a/packages/pigeon/test/version_test.dart b/packages/pigeon/test/version_test.dart
index a586856406af..1487b90b4e79 100644
--- a/packages/pigeon/test/version_test.dart
+++ b/packages/pigeon/test/version_test.dart
@@ -12,8 +12,8 @@ void main() {
     final String pubspecPath = '${Directory.current.path}/pubspec.yaml';
     final String pubspec = File(pubspecPath).readAsStringSync();
     final RegExp regex = RegExp(r'version:\s*(.*?) #');
-    final RegExpMatch match = regex.firstMatch(pubspec);
+    final RegExpMatch? match = regex.firstMatch(pubspec);
     expect(match, isNotNull);
-    expect(pigeonVersion, match.group(1).trim());
+    expect(pigeonVersion, match?.group(1)?.trim());
   });
 }