diff --git a/runtime/tools/dartfuzz/dartfuzz.dart b/runtime/tools/dartfuzz/dartfuzz.dart
index 2b73e28..1246d12 100644
--- a/runtime/tools/dartfuzz/dartfuzz.dart
+++ b/runtime/tools/dartfuzz/dartfuzz.dart
@@ -42,13 +42,13 @@
   ffiMethod,
   instanceMethod,
   callMethod,
-  extensionMethod
+  extensionMethod,
 }
 
 /// Base class for all methods in the program generated by DartFuzz.
 abstract class Method {
   Method(this.name, this.parameters, this.fuzzer)
-      : recursionAllowed = fuzzer.coinFlip() {
+    : recursionAllowed = fuzzer.coinFlip() {
     if (recursionAllowed) {
       // Add the recursion depth parameter.
       parameters.add(DartType.INT);
@@ -58,12 +58,17 @@
   String get recursionDepthParamName => '$paramName${parameters.length - 1}';
   DartType get returnType => parameters[0];
 
-  void emitCallParameters(int depth, bool isRecursiveCall,
-      {RhsFilter? rhsFilter}) {
+  void emitCallParameters(
+    int depth,
+    bool isRecursiveCall, {
+    RhsFilter? rhsFilter,
+  }) {
     if (isRecursiveCall && !recursionAllowed) {
       throw StateError('Did not expect a recursive call in $name');
     }
-    fuzzer.emitParenWrapped(() => fuzzer.emitCommaSeparated((int i) {
+    fuzzer.emitParenWrapped(
+      () => fuzzer.emitCommaSeparated(
+        (int i) {
           // If this function can be called recursively, the last parameter is the
           // recursion depth parameter.
           if (i == parameters.length - 1 && recursionAllowed) {
@@ -78,7 +83,11 @@
           } else {
             fuzzer.emitExpr(depth, parameters[i], rhsFilter: rhsFilter);
           }
-        }, parameters.length, start: 1));
+        },
+        parameters.length,
+        start: 1,
+      ),
+    );
   }
 
   void disableRecursionScope(Function callback) {
@@ -89,15 +98,18 @@
   }
 
   void emitRecursionBaseCase() {
-    fuzzer.emitIfStatement(() {
-      fuzzer.emit('$recursionDepthParamName >= ');
-      fuzzer.emitSmallPositiveInt();
-    }, () {
-      // Temporarily set recursionAllowed to false so that we don't have a
-      // recursive call in the return statement of the base case.
-      disableRecursionScope(fuzzer.emitReturn);
-      return false;
-    });
+    fuzzer.emitIfStatement(
+      () {
+        fuzzer.emit('$recursionDepthParamName >= ');
+        fuzzer.emitSmallPositiveInt();
+      },
+      () {
+        // Temporarily set recursionAllowed to false so that we don't have a
+        // recursive call in the return statement of the base case.
+        disableRecursionScope(fuzzer.emitReturn);
+        return false;
+      },
+    );
   }
 
   void emitFunctionBody() {
@@ -150,10 +162,12 @@
     fuzzer.emitNewline();
   }
 
-  String emitCall(int depth,
-      {RhsFilter? rhsFilter,
-      bool includeSemicolon = false,
-      bool isRecursiveCall = false}) {
+  String emitCall(
+    int depth, {
+    RhsFilter? rhsFilter,
+    bool includeSemicolon = false,
+    bool isRecursiveCall = false,
+  }) {
     var outputName = name;
     fuzzer.emitLn(outputName, newline: false);
     emitCallParameters(depth + 1, isRecursiveCall, rhsFilter: rhsFilter);
@@ -177,15 +191,18 @@
 /// Class for global methods generated by DartFuzz.
 class GlobalMethod extends Method {
   GlobalMethod(String name, List<DartType> parameters, DartFuzz fuzzer)
-      : super(name, parameters, fuzzer);
+    : super(name, parameters, fuzzer);
 }
 
 /// Class for ffi methods generated by DartFuzz.
 class FfiMethod extends Method {
   FfiMethod(
-      String namePrefix, int index, List<DartType> parameters, DartFuzz fuzzer)
-      : ffiCastName = '${namePrefix}FfiCast$index',
-        super('${namePrefix}Ffi$index', parameters, fuzzer);
+    String namePrefix,
+    int index,
+    List<DartType> parameters,
+    DartFuzz fuzzer,
+  ) : ffiCastName = '${namePrefix}FfiCast$index',
+      super('${namePrefix}Ffi$index', parameters, fuzzer);
 
   @override
   void emitFunctionBody() {
@@ -216,14 +233,19 @@
 /// Class for instance methods generated by DartFuzz.
 class InstanceMethod extends Method {
   InstanceMethod(
-      String name, List<DartType> parameters, DartFuzz fuzzer, this.className)
-      : super(name, parameters, fuzzer);
+    String name,
+    List<DartType> parameters,
+    DartFuzz fuzzer,
+    this.className,
+  ) : super(name, parameters, fuzzer);
 
   @override
-  String emitCall(int depth,
-      {RhsFilter? rhsFilter,
-      bool includeSemicolon = false,
-      bool isRecursiveCall = false}) {
+  String emitCall(
+    int depth, {
+    RhsFilter? rhsFilter,
+    bool includeSemicolon = false,
+    bool isRecursiveCall = false,
+  }) {
     var outputName = name;
     if (fuzzer.currentClassIndex == null) {
       // If we're calling an instance method from outside the class, then we
@@ -243,13 +265,15 @@
 
 class CallMethod extends Method {
   CallMethod(List<DartType> parameters, DartFuzz fuzzer, this.className)
-      : super('call', parameters, fuzzer);
+    : super('call', parameters, fuzzer);
 
   @override
-  String emitCall(int depth,
-      {RhsFilter? rhsFilter,
-      bool includeSemicolon = false,
-      bool isRecursiveCall = false}) {
+  String emitCall(
+    int depth, {
+    RhsFilter? rhsFilter,
+    bool includeSemicolon = false,
+    bool isRecursiveCall = false,
+  }) {
     String outputName;
     outputName = '$className()';
     fuzzer.emitLn(outputName, newline: false);
@@ -273,9 +297,14 @@
 
 // Class for extension methods generated by DartFuzz.
 class ExtensionMethod extends Method {
-  ExtensionMethod(String name, List<DartType> parameters, DartFuzz fuzzer,
-      this.className, this.extensionName, this.type)
-      : super(name, parameters, fuzzer);
+  ExtensionMethod(
+    String name,
+    List<DartType> parameters,
+    DartFuzz fuzzer,
+    this.className,
+    this.extensionName,
+    this.type,
+  ) : super(name, parameters, fuzzer);
   @override
   String emitCall(
     int depth, {
@@ -291,9 +320,10 @@
     // using a variable of the Dart type or using explicit extension
     // application.
     if (fuzzer.currentClassIndex == null || type != null) {
-      var invokingObject = type != null
-          ? fuzzer.pickScalarVar(type!.toNonNullable())
-          : '$className()';
+      var invokingObject =
+          type != null
+              ? fuzzer.pickScalarVar(type!.toNonNullable())
+              : '$className()';
 
       if (fuzzer.coinFlip()) {
         outputName = '$extensionName($invokingObject).$name';
@@ -345,11 +375,16 @@
     if (ffi) {
       typeToLibraryMethods[DartType.INT] = [
         ...[
-          DartLib('intComputation',
-              [DartType.VOID, ...List<DartType>.filled(4, DartType.INT)], true),
+          DartLib('intComputation', [
+            DartType.VOID,
+            ...List<DartType>.filled(4, DartType.INT),
+          ], true),
           DartLib('takeMaxUint16', [DartType.VOID, DartType.INT], true),
-          DartLib(
-              'sumPlus42', [DartType.VOID, DartType.INT, DartType.INT], true),
+          DartLib('sumPlus42', [
+            DartType.VOID,
+            DartType.INT,
+            DartType.INT,
+          ], true),
           DartLib('returnMaxUint8', [DartType.VOID, DartType.VOID], true),
           DartLib('returnMaxUint16', [DartType.VOID, DartType.VOID], true),
           DartLib('returnMaxUint32', [DartType.VOID, DartType.VOID], true),
@@ -358,10 +393,14 @@
           DartLib('returnMinInt32', [DartType.VOID, DartType.VOID], true),
           DartLib('takeMinInt16', [DartType.VOID, DartType.INT], true),
           DartLib('takeMinInt32', [DartType.VOID, DartType.INT], true),
-          DartLib('uintComputation',
-              [DartType.VOID, ...List<DartType>.filled(4, DartType.INT)], true),
-          DartLib('sumSmallNumbers',
-              [DartType.VOID, ...List<DartType>.filled(6, DartType.INT)], true),
+          DartLib('uintComputation', [
+            DartType.VOID,
+            ...List<DartType>.filled(4, DartType.INT),
+          ], true),
+          DartLib('sumSmallNumbers', [
+            DartType.VOID,
+            ...List<DartType>.filled(6, DartType.INT),
+          ], true),
           DartLib('takeMinInt8', [DartType.VOID, DartType.INT], true),
           DartLib('takeMaxUint32', [DartType.VOID, DartType.INT], true),
           DartLib('takeMaxUint8', [DartType.VOID, DartType.INT], true),
@@ -369,24 +408,33 @@
           DartLib('minInt32', [DartType.VOID, DartType.VOID], true),
           // Use small int to avoid overflow divergences due to size
           // differences in intptr_t on 32-bit and 64-bit platforms.
-          DartLib('sumManyIntsOdd',
-              [DartType.VOID, ...List<DartType>.filled(11, DartType.INT)], true,
-              restrictions: [
-                Restriction.none,
-                ...List<Restriction>.filled(11, Restriction.small)
-              ]),
-          DartLib('sumManyInts',
-              [DartType.VOID, ...List<DartType>.filled(10, DartType.INT)], true,
-              restrictions: [
-                Restriction.none,
-                ...List<Restriction>.filled(10, Restriction.small)
-              ]),
-          DartLib('regress37069',
-              [DartType.VOID, ...List<DartType>.filled(11, DartType.INT)], true,
-              restrictions: [
-                Restriction.none,
-                ...List<Restriction>.filled(11, Restriction.small)
-              ]),
+          DartLib(
+            'sumManyIntsOdd',
+            [DartType.VOID, ...List<DartType>.filled(11, DartType.INT)],
+            true,
+            restrictions: [
+              Restriction.none,
+              ...List<Restriction>.filled(11, Restriction.small),
+            ],
+          ),
+          DartLib(
+            'sumManyInts',
+            [DartType.VOID, ...List<DartType>.filled(10, DartType.INT)],
+            true,
+            restrictions: [
+              Restriction.none,
+              ...List<Restriction>.filled(10, Restriction.small),
+            ],
+          ),
+          DartLib(
+            'regress37069',
+            [DartType.VOID, ...List<DartType>.filled(11, DartType.INT)],
+            true,
+            restrictions: [
+              Restriction.none,
+              ...List<Restriction>.filled(11, Restriction.small),
+            ],
+          ),
         ],
         ...DartLib.intLibs,
       ];
@@ -394,37 +442,34 @@
       typeToLibraryMethods[DartType.DOUBLE] = [
         if (ffi) ...[
           DartLib('times1_337Float', [DartType.VOID, DartType.DOUBLE], true),
-          DartLib(
-              'sumManyDoubles',
-              [DartType.VOID, ...List<DartType>.filled(10, DartType.DOUBLE)],
-              true),
+          DartLib('sumManyDoubles', [
+            DartType.VOID,
+            ...List<DartType>.filled(10, DartType.DOUBLE),
+          ], true),
           DartLib('times1_337Double', [DartType.VOID, DartType.DOUBLE], true),
-          DartLib(
-              'sumManyNumbers',
-              [
-                DartType.VOID,
-                DartType.INT,
-                DartType.DOUBLE,
-                DartType.INT,
-                DartType.DOUBLE,
-                DartType.INT,
-                DartType.DOUBLE,
-                DartType.INT,
-                DartType.DOUBLE,
-                DartType.INT,
-                DartType.DOUBLE,
-                DartType.INT,
-                DartType.DOUBLE,
-                DartType.INT,
-                DartType.DOUBLE,
-                DartType.INT,
-                DartType.DOUBLE,
-                DartType.INT,
-                DartType.DOUBLE,
-                DartType.INT,
-                DartType.DOUBLE
-              ],
-              true),
+          DartLib('sumManyNumbers', [
+            DartType.VOID,
+            DartType.INT,
+            DartType.DOUBLE,
+            DartType.INT,
+            DartType.DOUBLE,
+            DartType.INT,
+            DartType.DOUBLE,
+            DartType.INT,
+            DartType.DOUBLE,
+            DartType.INT,
+            DartType.DOUBLE,
+            DartType.INT,
+            DartType.DOUBLE,
+            DartType.INT,
+            DartType.DOUBLE,
+            DartType.INT,
+            DartType.DOUBLE,
+            DartType.INT,
+            DartType.DOUBLE,
+            DartType.INT,
+            DartType.DOUBLE,
+          ], true),
           DartLib('inventFloatValue', [DartType.VOID, DartType.VOID], true),
           DartLib('smallDouble', [DartType.VOID, DartType.VOID], true),
         ],
@@ -438,8 +483,16 @@
 
 /// Class that generates a random, but runnable Dart program for fuzz testing.
 class DartFuzz {
-  DartFuzz(this.seed, this.fp, this.ffi, this.flatTp, this.file,
-      {this.minimize = false, this.smask, this.emask});
+  DartFuzz(
+    this.seed,
+    this.fp,
+    this.ffi,
+    this.flatTp,
+    this.file, {
+    this.minimize = false,
+    this.smask,
+    this.emask,
+  });
 
   void run() {
     // Initialize program variables.
@@ -459,19 +512,31 @@
     globalVars = fillTypes1(limit: numGlobalVars);
     globalVars.addAll(dartType.allTypes);
     globalMethods = getMethods(
-        numGlobalMethods, numMethodParams, MethodType.globalMethod,
-        namePrefix: methodName);
+      numGlobalMethods,
+      numMethodParams,
+      MethodType.globalMethod,
+      namePrefix: methodName,
+    );
     classFields = fillTypes2(limit2: numClasses, limit1: numLocalVars);
     final numClassMethods = 1 + numClasses - classFields.length;
-    classMethods = getClassMethods(classFields.length, numClassMethods,
-        numMethodParams, fillTypes1(limit: numMethodParams));
+    classMethods = getClassMethods(
+      classFields.length,
+      numClassMethods,
+      numMethodParams,
+      fillTypes1(limit: numMethodParams),
+    );
     virtualClassMethods = <Map<int, List<int>>>[];
     classParents = <int>[];
     // Setup optional ffi methods and types.
     if (ffi) {
-      globalMethods.addAll(getMethods(
-          numGlobalMethods, numMethodParams, MethodType.ffiMethod,
-          namePrefix: methodName));
+      globalMethods.addAll(
+        getMethods(
+          numGlobalMethods,
+          numMethodParams,
+          MethodType.ffiMethod,
+          namePrefix: methodName,
+        ),
+      );
     }
     // Generate.
     emitHeader();
@@ -479,9 +544,13 @@
     emitMethods(globalMethods);
     for (var i = 0; i < numDartTypeExtensions; ++i) {
       var type = oneOfSet(dartType.allTypes);
-      emitAndAddExtensionMethods(globalMethods, type.name, '${methodName}E$i',
-          '$methodName${i}_Extension',
-          type: type);
+      emitAndAddExtensionMethods(
+        globalMethods,
+        type.name,
+        '${methodName}E$i',
+        '$methodName${i}_Extension',
+        type: type,
+      );
     }
     emitClasses();
     emitMain();
@@ -494,15 +563,21 @@
     assert(localVars.isEmpty);
   }
 
-  List<Method> getMethods(int maxMethods, int maxParams, MethodType methodType,
-      {String? className,
-      String? extensionName,
-      String? namePrefix,
-      DartType? type}) {
+  List<Method> getMethods(
+    int maxMethods,
+    int maxParams,
+    MethodType methodType, {
+    String? className,
+    String? extensionName,
+    String? namePrefix,
+    DartType? type,
+  }) {
     final list = <Method>[];
     for (var i = 0, n = chooseOneUpTo(maxMethods); i < n; i++) {
       final params = fillTypes1(
-          limit: maxParams, isFfi: methodType == MethodType.ffiMethod);
+        limit: maxParams,
+        isFfi: methodType == MethodType.ffiMethod,
+      );
       switch (methodType) {
         case MethodType.globalMethod:
           list.add(GlobalMethod('$namePrefix$i', params, this));
@@ -514,8 +589,16 @@
           list.add(InstanceMethod('$namePrefix$i', params, this, className!));
           break;
         case MethodType.extensionMethod:
-          list.add(ExtensionMethod(
-              '$namePrefix$i', params, this, className!, extensionName!, type));
+          list.add(
+            ExtensionMethod(
+              '$namePrefix$i',
+              params,
+              this,
+              className!,
+              extensionName!,
+              type,
+            ),
+          );
           break;
         default:
           break;
@@ -524,13 +607,21 @@
     return list;
   }
 
-  List<List<Method>> getClassMethods(int numClasses, int maxMethods,
-      int maxParams, List<DartType> callMethodParams) {
+  List<List<Method>> getClassMethods(
+    int numClasses,
+    int maxMethods,
+    int maxParams,
+    List<DartType> callMethodParams,
+  ) {
     final methodsForAllClasses = <List<Method>>[];
     for (var i = 0; i < numClasses; i++) {
       final methodsForCurrentClass = getMethods(
-          maxMethods, maxParams, MethodType.instanceMethod,
-          className: 'X$i', namePrefix: '$methodName${i}_');
+        maxMethods,
+        maxParams,
+        MethodType.instanceMethod,
+        className: 'X$i',
+        namePrefix: '$methodName${i}_',
+      );
       // Add the call method for the current class. The prototype for the call
       // method is pre-decided. This is because we are possibly overriding the
       // parent class' call method, in which case the prototype should be the
@@ -566,8 +657,11 @@
 
   void emitZero() => emit('0');
 
-  void emitTryCatchFinally(Function tryBody, Function catchBody,
-      {Function? finallyBody}) {
+  void emitTryCatchFinally(
+    Function tryBody,
+    Function catchBody, {
+    Function? finallyBody,
+  }) {
     emitLn('try ', newline: false);
     emitBraceWrapped(() => tryBody());
     emit(' on OutOfMemoryError ');
@@ -582,8 +676,11 @@
     }
   }
 
-  dynamic emitWrapped(List<String> pair, Function exprEmitter,
-      {bool shouldIndent = true}) {
+  dynamic emitWrapped(
+    List<String> pair,
+    Function exprEmitter, {
+    bool shouldIndent = true,
+  }) {
     assert(pair.length == 2);
     emit(pair[0]);
     if (shouldIndent) {
@@ -601,10 +698,15 @@
     return result;
   }
 
-  dynamic emitParenWrapped(Function exprEmitter,
-      {bool includeSemicolon = false}) {
-    final result =
-        emitWrapped(const ['(', ')'], exprEmitter, shouldIndent: false);
+  dynamic emitParenWrapped(
+    Function exprEmitter, {
+    bool includeSemicolon = false,
+  }) {
+    final result = emitWrapped(
+      const ['(', ')'],
+      exprEmitter,
+      shouldIndent: false,
+    );
     if (includeSemicolon) {
       emit(';');
     }
@@ -617,8 +719,12 @@
   dynamic emitSquareBraceWrapped(Function exprEmitter) =>
       emitWrapped(const ['[', ']'], exprEmitter, shouldIndent: false);
 
-  dynamic emitCommaSeparated(Function(int) elementBuilder, int length,
-      {int start = 0, bool newline = false}) {
+  dynamic emitCommaSeparated(
+    Function(int) elementBuilder,
+    int length, {
+    int start = 0,
+    bool newline = false,
+  }) {
     for (var i = start; i < length; ++i) {
       elementBuilder(i);
       if (i + 1 != length) {
@@ -642,8 +748,10 @@
   }
 
   bool emitIfStatement(
-      Function ifConditionEmitter, bool Function() ifBodyEmitter,
-      {bool Function()? elseBodyEmitter}) {
+    Function ifConditionEmitter,
+    bool Function() ifBodyEmitter, {
+    bool Function()? elseBodyEmitter,
+  }) {
     emitLn('if ', newline: false);
     emitParenWrapped(ifConditionEmitter);
     emit(' ');
@@ -656,12 +764,17 @@
     return ifMayFallThrough || elseMayFallThrough;
   }
 
-  void emitImport(String library, {String? asName}) => (asName == null)
-      ? emitLn("import '$library';")
-      : emitLn("import '$library' as $asName;");
+  void emitImport(String library, {String? asName}) =>
+      (asName == null)
+          ? emitLn("import '$library';")
+          : emitLn("import '$library' as $asName;");
 
-  void emitBinaryComparison(Function e1, String op, Function e2,
-      {bool includeSemicolon = false}) {
+  void emitBinaryComparison(
+    Function e1,
+    String op,
+    Function e2, {
+    bool includeSemicolon = false,
+  }) {
     e1();
     emit(' $op ');
     e2();
@@ -688,34 +801,80 @@
     skipExpr = false;
   }
 
-  void emitMinimizedLiteral(DartType tp) {
-    switch (tp) {
-      case DartType.BOOL:
-        emit('true');
-        break;
-      case DartType.INT:
-        emit('1');
-        break;
-      case DartType.DOUBLE:
-        emit('1.0');
-        break;
-      case DartType.STRING:
-        emit('"a"');
-        break;
-      case DartType.LIST_INT:
-        emit('[1]');
-        break;
-      case DartType.SET_INT:
-        emit('{1}');
-        break;
-      case DartType.MAP_INT_STRING:
-        emit('{1: "a"}');
-        break;
-      default:
-        throw 'Unknown DartType $tp';
+  void _emitMinimizedLiteralHelper(StringBuffer sb, DartType tp) {
+    // isListType returns true for types like Uint8List which can't be written
+    // simply with a list notation, so check this before the isListType check.
+    if (tp.hasConstructor(tp)) {
+      final constructorName = tp.constructors(tp).first;
+      if (constructorName.isNotEmpty) {
+        sb.write('${tp.name}.$constructorName');
+      } else {
+        sb.write(tp.name);
+      }
+      sb.write('(');
+      final paramTypes = tp.constructorParameters(tp, constructorName);
+      if (paramTypes.isNotEmpty) {
+        _emitMinimizedLiteralHelper(sb, paramTypes[0]);
+        for (int i = 1; i < paramTypes.length; i++) {
+          sb.write(',');
+          _emitMinimizedLiteralHelper(sb, paramTypes[i]);
+        }
+      }
+      sb.write(')');
+    } else if (DartType.isListType(tp)) {
+      sb.write('[');
+      _emitMinimizedLiteralHelper(sb, tp.elementType(tp));
+      sb.write(']');
+    } else if (DartType.isSetType(tp)) {
+      sb.write('{');
+      _emitMinimizedLiteralHelper(sb, tp.elementType(tp));
+      sb.write('}');
+    } else if (DartType.isMapType(tp)) {
+      sb.write('{');
+      _emitMinimizedLiteralHelper(sb, tp.indexType(tp));
+      sb.write(':');
+      _emitMinimizedLiteralHelper(sb, tp.elementType(tp));
+      sb.write('}');
+    } else {
+      switch (tp.toNonNullable()) {
+        case DartType.ENDIAN:
+          sb.write('Endian.little');
+          break;
+        case DartType.NUM:
+          if (coinFlip()) {
+            _emitMinimizedLiteralHelper(sb, DartType.INT);
+          } else {
+            _emitMinimizedLiteralHelper(sb, DartType.DOUBLE);
+          }
+          break;
+        case DartType.BOOL:
+          sb.write('true');
+          break;
+        case DartType.INT:
+          sb.write('1');
+          break;
+        case DartType.DOUBLE:
+          sb.write('1.0');
+          break;
+        case DartType.STRING:
+          sb.write('"a"');
+          break;
+        default:
+          if (!tp.isNullable) {
+            throw 'Unknown DartType $tp';
+          }
+          // Only fall back to null if an non-null element cannot be generated.
+          sb.write('null');
+      }
     }
   }
 
+  void emitMinimizedLiteral(DartType tp) {
+    final sb = StringBuffer();
+    _emitMinimizedLiteralHelper(sb, tp);
+    emit(sb.toString());
+  }
+
   // Process the opening of a statement.
   // Determine whether the statement should be skipped based on the
   // statement index stored in stmtCntr and the statement mask stored
@@ -811,8 +970,10 @@
   void emitHeader() {
     emitLn('// The Dart Project Fuzz Tester ($version).');
     emitLn('// Program generated as:');
-    emitLn('//   dart dartfuzz.dart --seed $seed --${fp ? "" : "no-"}fp '
-        '--${ffi ? "" : "no-"}ffi --${flatTp ? "" : "no-"}flat');
+    emitLn(
+      '//   dart dartfuzz.dart --seed $seed --${fp ? "" : "no-"}fp '
+      '--${ffi ? "" : "no-"}ffi --${flatTp ? "" : "no-"}flat',
+    );
     emitLn('// @dart=2.14');
     emitNewline();
     emitImport('dart:async');
@@ -831,12 +992,20 @@
     emitNewline();
   }
 
-  void emitFfiCast(String dartFuncName, String ffiFuncName, String typeName,
-      List<DartType> pars) {
+  void emitFfiCast(
+    String dartFuncName,
+    String ffiFuncName,
+    String typeName,
+    List<DartType> pars,
+  ) {
     emit('${pars[0].name} Function');
-    emitParenWrapped(() => emitCommaSeparated(
-        (int i) => emit('${pars[i].name}'), pars.length,
-        start: 1));
+    emitParenWrapped(
+      () => emitCommaSeparated(
+        (int i) => emit('${pars[i].name}'),
+        pars.length,
+        start: 1,
+      ),
+    );
     emit(' $dartFuncName = ffi.Pointer.fromFunction<$typeName>');
     emitParenWrapped(() {
       emit('$ffiFuncName, ');
@@ -924,25 +1093,35 @@
       emitNewline();
       emitNewline();
       emitAndAddExtensionMethods(
-          classMethods[currentClassIndex!],
-          'X$currentClassIndex',
-          'XE$currentClassIndex',
-          '$methodName${currentClassIndex}_Extension');
+        classMethods[currentClassIndex!],
+        'X$currentClassIndex',
+        'XE$currentClassIndex',
+        '$methodName${currentClassIndex}_Extension',
+      );
       currentClassIndex = null;
     }
   }
 
   void emitAndAddExtensionMethods(
-      List<Method> methodList, className, extensionName, namePrefix,
-      {DartType? type}) {
+    List<Method> methodList,
+    className,
+    extensionName,
+    namePrefix, {
+    DartType? type,
+  }) {
     var endIndex = methodList.length;
-    methodList.addAll(getMethods(numExtensionMethodsPerClass, numMethodParams,
+    methodList.addAll(
+      getMethods(
+        numExtensionMethodsPerClass,
+        numMethodParams,
         MethodType.extensionMethod,
         className: className,
         // Randomly select between named and anonymous extensions.
         extensionName: coinFlip() ? extensionName : '',
         namePrefix: namePrefix,
-        type: type));
+        type: type,
+      ),
+    );
     emit('extension $extensionName on $className ');
     emitBraceWrapped(() {
       // Emit the newly added methods.
@@ -960,74 +1139,93 @@
 
   void emitLoadFfiLib() {
     if (ffi) {
-      emitLn('// The following throws an uncaught exception if the ffi library '
-          'is not found.');
-      emitLn('// By not catching this exception, we terminate the program with '
-          'a full stack trace');
+      emitLn(
+        '// The following throws an uncaught exception if the ffi library '
+        'is not found.',
+      );
+      emitLn(
+        '// By not catching this exception, we terminate the program with '
+        'a full stack trace',
+      );
       emitLn('// which, in turn, flags the problem prominently');
-      emitIfStatement(() => emit('ffiTestFunctions == null'),
-          () => emitPrint('Did not load ffi test functions'));
+      emitIfStatement(
+        () => emit('ffiTestFunctions == null'),
+        () => emitPrint('Did not load ffi test functions'),
+      );
       emitNewline();
     }
   }
 
   void emitMain() => emitFunctionDefinition('main', () {
-        emitLoadFfiLib();
+    emitLoadFfiLib();
 
-        // Call each global method once.
-        for (var i = 0; i < globalMethods.length; i++) {
-          late String outputName;
-          emitTryCatchFinally(
-              () => outputName =
-                  globalMethods[i].emitCall(1, includeSemicolon: true),
-              () => emitPrint('${outputName}() throws'));
-          emitNewline();
-        }
+    // Call each global method once.
+    for (var i = 0; i < globalMethods.length; i++) {
+      late String outputName;
+      emitTryCatchFinally(
+        () => outputName = globalMethods[i].emitCall(1, includeSemicolon: true),
+        () => emitPrint('${outputName}() throws'),
+      );
+      emitNewline();
+    }
 
-        // Call each class method once.
-        for (var i = 0; i < classMethods.length; i++) {
-          for (var j = 0; j < classMethods[i].length; j++) {
+    // Call each class method once.
+    for (var i = 0; i < classMethods.length; i++) {
+      for (var j = 0; j < classMethods[i].length; j++) {
+        late String outputName;
+        emitNewline();
+        emitTryCatchFinally(
+          () =>
+              outputName = classMethods[i][j].emitCall(
+                1,
+                includeSemicolon: true,
+              ),
+          () => emitPrint('$outputName throws'),
+        );
+      }
+      // Call each virtual class method once.
+      var parentClass = classParents[i];
+      while (parentClass >= 0) {
+        if (virtualClassMethods[i].containsKey(parentClass)) {
+          for (
+            var j = 0;
+            j < virtualClassMethods[i][parentClass]!.length;
+            j++
+          ) {
             late String outputName;
             emitNewline();
             emitTryCatchFinally(
-                () => outputName =
-                    classMethods[i][j].emitCall(1, includeSemicolon: true),
-                () => emitPrint('$outputName throws'));
-          }
-          // Call each virtual class method once.
-          var parentClass = classParents[i];
-          while (parentClass >= 0) {
-            if (virtualClassMethods[i].containsKey(parentClass)) {
-              for (var j = 0;
-                  j < virtualClassMethods[i][parentClass]!.length;
-                  j++) {
-                late String outputName;
-                emitNewline();
-                emitTryCatchFinally(
-                    () => outputName = classMethods[parentClass][j]
-                        .emitCall(1, includeSemicolon: true),
-                    () => emitPrint('$outputName throws'));
-              }
-            }
-            parentClass = classParents[parentClass];
+              () =>
+                  outputName = classMethods[parentClass][j].emitCall(
+                    1,
+                    includeSemicolon: true,
+                  ),
+              () => emitPrint('$outputName throws'),
+            );
           }
         }
+        parentClass = classParents[parentClass];
+      }
+    }
 
-        emitNewline();
-        emitTryCatchFinally(() {
-          emitLn('X${classFields.length - 1}().run();', newline: false);
-        }, () {
-          emitPrint('X${classFields.length - 1}().run() throws');
-        });
+    emitNewline();
+    emitTryCatchFinally(
+      () {
+        emitLn('X${classFields.length - 1}().run();', newline: false);
+      },
+      () {
+        emitPrint('X${classFields.length - 1}().run() throws');
+      },
+    );
 
+    emitNewline();
+    emitTryCatchFinally(() {
+      for (var i = 0; i < globalVars.length; i++) {
+        emitPrint('$varName$i: \$$varName$i');
         emitNewline();
-        emitTryCatchFinally(() {
-          for (var i = 0; i < globalVars.length; i++) {
-            emitPrint('$varName$i: \$$varName$i');
-            emitNewline();
-          }
-        }, () => emitPrint('print() throws'));
-      });
+      }
+    }, () => emitPrint('print() throws'));
+  });
 
   //
   // Declarations.
@@ -1037,17 +1235,23 @@
     for (var i = 0; i < vars.length; i++) {
       var tp = vars[i];
       final varName = '$name$i';
-      emitVariableDeclaration(varName, tp,
-          initializerEmitter: () => emitConstructorOrLiteral(0, tp));
+      emitVariableDeclaration(
+        varName,
+        tp,
+        initializerEmitter: () => emitConstructorOrLiteral(0, tp),
+      );
     }
     emitNewline();
   }
 
-  void emitVariableDeclaration(String name, DartType tp,
-      {Function? initializerEmitter,
-      bool indent = true,
-      bool newline = true,
-      bool includeSemicolon = true}) {
+  void emitVariableDeclaration(
+    String name,
+    DartType tp, {
+    Function? initializerEmitter,
+    bool indent = true,
+    bool newline = true,
+    bool includeSemicolon = true,
+  }) {
     final typeName = tp.dartName;
     if (indent) {
       emitIndentation();
@@ -1062,10 +1266,14 @@
     }
   }
 
-  void emitParDecls(List<DartType> pars) => emitCommaSeparated((int i) {
-        var tp = pars[i];
-        emit('${tp.dartName} $paramName$i');
-      }, pars.length, start: 1);
+  void emitParDecls(List<DartType> pars) => emitCommaSeparated(
+    (int i) {
+      var tp = pars[i];
+      emit('${tp.dartName} $paramName$i');
+    },
+    pars.length,
+    start: 1,
+  );
 
   //
   // Comments (for FE and analysis tools).
@@ -1171,12 +1379,16 @@
 
   // Emit a one-way if statement.
   bool emitIf1(int depth) => emitIfStatement(
-      () => emitExpr(0, DartType.BOOL), () => emitStatements(depth + 1));
+    () => emitExpr(0, DartType.BOOL),
+    () => emitStatements(depth + 1),
+  );
 
   // Emit a two-way if statement.
   bool emitIf2(int depth) => emitIfStatement(
-      () => emitExpr(0, DartType.BOOL), () => emitStatements(depth + 1),
-      elseBodyEmitter: () => emitStatements(depth + 1));
+    () => emitExpr(0, DartType.BOOL),
+    () => emitStatements(depth + 1),
+    elseBodyEmitter: () => emitStatements(depth + 1),
+  );
 
   // Emit a simple increasing for-loop.
   bool emitFor(int depth) {
@@ -1188,10 +1400,19 @@
     emitLn('for ', newline: false);
     emitParenWrapped(() {
       final name = '$localName$i';
-      emitVariableDeclaration(name, DartType.INT,
-          initializerEmitter: emitZero, newline: false, indent: false);
-      emitBinaryComparison(() => emit(name), '<', emitSmallPositiveInt,
-          includeSemicolon: true);
+      emitVariableDeclaration(
+        name,
+        DartType.INT,
+        initializerEmitter: emitZero,
+        newline: false,
+        indent: false,
+      );
+      emitBinaryComparison(
+        () => emit(name),
+        '<',
+        emitSmallPositiveInt,
+        includeSemicolon: true,
+      );
       emit('$name++');
     });
     emitBraceWrapped(() {
@@ -1284,11 +1505,15 @@
     emitIndentation();
     emitBraceWrapped(() {
       final name = '$localName$i';
-      emitVariableDeclaration(name, DartType.INT,
-          initializerEmitter: () => emitSmallPositiveInt());
+      emitVariableDeclaration(
+        name,
+        DartType.INT,
+        initializerEmitter: () => emitSmallPositiveInt(),
+      );
       emitLn('while ', newline: false);
       emitParenWrapped(
-          () => emitBinaryComparison(() => emit('--$name'), '>', emitZero));
+        () => emitBinaryComparison(() => emit('--$name'), '>', emitZero),
+      );
       emitBraceWrapped(() {
         nest++;
         iterVars.add(name);
@@ -1325,9 +1550,13 @@
       });
       emit(' while ');
       emitParenWrapped(
-          () => emitBinaryComparison(
-              () => emit('++$name'), '<', emitSmallPositiveInt),
-          includeSemicolon: true);
+        () => emitBinaryComparison(
+          () => emit('++$name'),
+          '<',
+          emitSmallPositiveInt,
+        ),
+        includeSemicolon: true,
+      );
     });
     emitNewline();
     return true;
@@ -1359,8 +1588,10 @@
       emitBraceWrapped(() {
         bodyEmitter();
         emitNewline();
-        emitLn('break;',
-            newline: false); // always generate, avoid FE complaints
+        emitLn(
+          'break;',
+          newline: false,
+        ); // always generate, avoid FE complaints
       });
     }
 
@@ -1371,8 +1602,10 @@
       var step = chooseOneUpTo(10);
       final maxCases = 3;
       for (var i = 0; i < maxCases; i++, start += step) {
-        emitCase(() => emitStatement(depth + 1),
-            kase: (i == 2 && coinFlip()) ? null : start);
+        emitCase(
+          () => emitStatement(depth + 1),
+          kase: (i == 2 && coinFlip()) ? null : start,
+        );
         if (i + 1 != maxCases) {
           emitNewline();
         }
@@ -1388,11 +1621,15 @@
       var tp = oneOfSet(dartType.allTypes);
       final i = localVars.length;
       final name = '$localName$i';
-      emitVariableDeclaration(name, tp, initializerEmitter: () {
-        localVars.add(null); // declared, but don't use
-        emitExpr(0, tp);
-        localVars.removeLast(); // will get type
-      });
+      emitVariableDeclaration(
+        name,
+        tp,
+        initializerEmitter: () {
+          localVars.add(null); // declared, but don't use
+          emitExpr(0, tp);
+          localVars.removeLast(); // will get type
+        },
+      );
       localVars.add(tp);
       emitStatements(depth + 1);
       localVars.removeLast();
@@ -1562,8 +1799,12 @@
     emit("'");
   }
 
-  void emitElementExpr(int depth, DartType tp,
-      {RhsFilter? rhsFilter, bool isConst = false}) {
+  void emitElementExpr(
+    int depth,
+    DartType tp, {
+    RhsFilter? rhsFilter,
+    bool isConst = false,
+  }) {
     // Inside a constant collection, keep collection elements constants too.
     if (isConst) {
       if (DartType.isCollectionType(tp)) {
@@ -1579,8 +1820,12 @@
     }
   }
 
-  void emitElement(int depth, DartType tp,
-      {RhsFilter? rhsFilter, bool isConst = false}) {
+  void emitElement(
+    int depth,
+    DartType tp, {
+    RhsFilter? rhsFilter,
+    bool isConst = false,
+  }) {
     // Get the element type contained in type tp.
     // E.g. element type of List<String> is String.
     final elementType = dartType.elementType(tp);
@@ -1592,12 +1837,20 @@
       emitElementExpr(depth, indexType, rhsFilter: rhsFilter, isConst: isConst);
       emit(' : ');
       // Emit construct for the map value type.
-      emitElementExpr(depth, elementType,
-          rhsFilter: rhsFilter, isConst: isConst);
+      emitElementExpr(
+        depth,
+        elementType,
+        rhsFilter: rhsFilter,
+        isConst: isConst,
+      );
     } else {
       // List and Set types.
-      emitElementExpr(depth, elementType,
-          rhsFilter: rhsFilter, isConst: isConst);
+      emitElementExpr(
+        depth,
+        elementType,
+        rhsFilter: rhsFilter,
+        isConst: isConst,
+      );
     }
   }
 
@@ -1605,8 +1858,11 @@
     var r = (depth <= exprDepth) ? choose(10) : 10;
     // TODO (felih): disable complex collection constructs for new types for
     // now.
-    if (!{DartType.MAP_INT_STRING, DartType.LIST_INT, DartType.SET_INT}
-        .contains(tp)) {
+    if (!{
+      DartType.MAP_INT_STRING,
+      DartType.LIST_INT,
+      DartType.SET_INT,
+    }.contains(tp)) {
       emitElement(depth, tp, rhsFilter: rhsFilter);
       return;
     }
@@ -1618,8 +1874,9 @@
         break;
       case 1:
         emitLn('if ', newline: false);
-        emitParenWrapped(() =>
-            emitElementExpr(depth + 1, DartType.BOOL, rhsFilter: rhsFilter));
+        emitParenWrapped(
+          () => emitElementExpr(depth + 1, DartType.BOOL, rhsFilter: rhsFilter),
+        );
         emitCollectionElement(depth + 1, tp, rhsFilter: rhsFilter);
         if (coinFlip()) {
           emitNewline();
@@ -1640,26 +1897,47 @@
             localVars.add(null); // declared, but don't use
             switch (choose(3)) {
               case 0:
-                emitVariableDeclaration(local, DartType.INT,
-                    initializerEmitter: emitZero, indent: false);
-                emitBinaryComparison(() => emit(local), '<',
-                    () => emitSmallPositiveInt(limit: 16),
-                    includeSemicolon: true);
+                emitVariableDeclaration(
+                  local,
+                  DartType.INT,
+                  initializerEmitter: emitZero,
+                  indent: false,
+                );
+                emitBinaryComparison(
+                  () => emit(local),
+                  '<',
+                  () => emitSmallPositiveInt(limit: 16),
+                  includeSemicolon: true,
+                );
                 emit('$local++');
                 break;
               case 1:
-                emitVariableDeclaration(local, DartType.INT,
-                    includeSemicolon: false, indent: false);
+                emitVariableDeclaration(
+                  local,
+                  DartType.INT,
+                  includeSemicolon: false,
+                  indent: false,
+                );
                 emit(' in ');
-                emitCollection(depth + 1, DartType.LIST_INT,
-                    rhsFilter: rhsFilter);
+                emitCollection(
+                  depth + 1,
+                  DartType.LIST_INT,
+                  rhsFilter: rhsFilter,
+                );
                 break;
               default:
-                emitVariableDeclaration(local, DartType.INT,
-                    includeSemicolon: false, indent: false);
+                emitVariableDeclaration(
+                  local,
+                  DartType.INT,
+                  includeSemicolon: false,
+                  indent: false,
+                );
                 emit(' in ');
-                emitCollection(depth + 1, DartType.SET_INT,
-                    rhsFilter: rhsFilter);
+                emitCollection(
+                  depth + 1,
+                  DartType.SET_INT,
+                  rhsFilter: rhsFilter,
+                );
                 break;
             }
             localVars.removeLast(); // will get type
@@ -1701,9 +1979,10 @@
       // Collection length decreases as depth increases.
       var collectionLength = max(1, 8 - depth);
       emitCommaSeparated(
-          (int _) => emitCollectionElement(depth, tp, rhsFilter: rhsFilter),
-          chooseOneUpTo(collectionLength),
-          newline: DartType.isMapType(tp));
+        (int _) => emitCollectionElement(depth, tp, rhsFilter: rhsFilter),
+        chooseOneUpTo(collectionLength),
+        newline: DartType.isMapType(tp),
+      );
     }, shouldIndent: DartType.isMapType(tp));
   }
 
@@ -1719,14 +1998,16 @@
       var elementType = dartType.elementType(tp);
       l = 'const <${elementType.dartName}>{';
       r = '}';
-      canHaveElements = (elementType != DartType.DOUBLE) &&
+      canHaveElements =
+          (elementType != DartType.DOUBLE) &&
           (elementType != DartType.DOUBLE_NULLABLE);
     } else if (DartType.isMapType(tp)) {
       var indexType = dartType.indexType(tp);
       var elementType = dartType.elementType(tp);
       l = 'const <${indexType.dartName},${elementType.dartName}>{';
       r = '}';
-      canHaveElements = (indexType != DartType.DOUBLE) &&
+      canHaveElements =
+          (indexType != DartType.DOUBLE) &&
           (indexType != DartType.DOUBLE_NULLABLE);
     } else {
       throw "Unrecognized collection type $tp";
@@ -1739,13 +2020,19 @@
       emit(r);
       return;
     }
-    emitWrapped([l, r],
-        () => emitElement(depth, tp, rhsFilter: rhsFilter, isConst: true),
-        shouldIndent: DartType.isMapType(tp));
+    emitWrapped(
+      [l, r],
+      () => emitElement(depth, tp, rhsFilter: rhsFilter, isConst: true),
+      shouldIndent: DartType.isMapType(tp),
+    );
   }
 
-  void emitLiteral(int depth, DartType tp,
-      {bool smallPositiveValue = false, RhsFilter? rhsFilter}) {
+  void emitLiteral(
+    int depth,
+    DartType tp, {
+    bool smallPositiveValue = false,
+    RhsFilter? rhsFilter,
+  }) {
     if (tp.isNullable) {
       if (choose(20) == 0) {
         emitNull();
@@ -1793,8 +2080,12 @@
 
   // Emit a constructor for a type, this can either be a trivial constructor
   // (i.e. parsed from a literal) or an actual function invocation.
-  void emitConstructorOrLiteral(int depth, DartType tp,
-      {RhsFilter? rhsFilter, bool includeSemicolon = false}) {
+  void emitConstructorOrLiteral(
+    int depth,
+    DartType tp, {
+    RhsFilter? rhsFilter,
+    bool includeSemicolon = false,
+  }) {
     // If there is at least one non trivial constructor for the type tp
     // select one of these constructors.
     if (dartType.hasConstructor(tp)) {
@@ -1812,14 +2103,20 @@
       }
       emitParenWrapped(() {
         // Iterate over constructor parameters.
-        var constructorParameters =
-            dartType.constructorParameters(tp, constructor);
+        var constructorParameters = dartType.constructorParameters(
+          tp,
+          constructor,
+        );
         emitCommaSeparated((int i) {
           // If we are emitting a constructor parameter, we want to use small
           // values to avoid programs that run out of memory.
           // TODO (felih): maybe allow occasionally?
-          emitLiteral(depth + 1, constructorParameters[i],
-              smallPositiveValue: true, rhsFilter: rhsFilter);
+          emitLiteral(
+            depth + 1,
+            constructorParameters[i],
+            smallPositiveValue: true,
+            rhsFilter: rhsFilter,
+          );
         }, constructorParameters.length);
       });
     } else {
@@ -1832,8 +2129,11 @@
   }
 
   // Pick an existing variable of the given type.
-  String? pickScalarVar(DartType tp,
-      {bool isLhs = false, RhsFilter? rhsFilter}) {
+  String? pickScalarVar(
+    DartType tp, {
+    bool isLhs = false,
+    RhsFilter? rhsFilter,
+  }) {
     // Randomly specialize interface type, unless emitting left hand side.
     if (!isLhs) tp = maybeSpecializeInterface(tp);
     // Collect all choices from globals, fields, locals, and parameters.
@@ -1895,8 +2195,11 @@
     return '${choices.elementAt(choose(choices.length))}';
   }
 
-  String? emitScalarVar(DartType tp,
-      {bool isLhs = false, RhsFilter? rhsFilter}) {
+  String? emitScalarVar(
+    DartType tp, {
+    bool isLhs = false,
+    RhsFilter? rhsFilter,
+  }) {
     final emittedVar = pickScalarVar(tp, isLhs: isLhs, rhsFilter: rhsFilter);
     if (emittedVar != null) {
       if (rhsFilter != null && (emittedVar == rhsFilter.lhsVar)) {
@@ -1907,8 +2210,13 @@
     return emittedVar;
   }
 
-  String? emitSubscriptedVar(int depth, DartType tp,
-      {bool isLhs = false, String? assignOp, RhsFilter? rhsFilter}) {
+  String? emitSubscriptedVar(
+    int depth,
+    DartType tp, {
+    bool isLhs = false,
+    String? assignOp,
+    RhsFilter? rhsFilter,
+  }) {
     String? ret;
     // Check if type tp is an indexable element of some other type.
     if (dartType.isIndexableElementType(tp)) {
@@ -1926,33 +2234,48 @@
       final indexType = dartType.indexType(iterType);
       // Emit a variable of the selected list or map type.
       ret = emitScalarVar(iterType, isLhs: isLhs, rhsFilter: rhsFilter);
-      emitSquareBraceWrapped(() =>
-          // Emit an expression resolving into the index type. For
-          // collection type, only constant collections are used
-          // to avoid rehashing the same value into many entries.
-          DartType.isCollectionType(indexType)
-              ? emitConstCollection(depth + 1, indexType)
-              : emitExpr(depth + 1, indexType));
+      emitSquareBraceWrapped(
+        () =>
+            // Emit an expression resolving into the index type. For
+            // collection type, only constant collections are used
+            // to avoid rehashing the same value into many entries.
+            DartType.isCollectionType(indexType)
+                ? emitConstCollection(depth + 1, indexType)
+                : emitExpr(depth + 1, indexType),
+      );
       // Map.[] and Expando.[] have a nullable result, but we should not write
       // map[key]! = value.
       if (!tp.isNullable && !isLhs) {
         emit('!');
       }
     } else {
-      ret = emitScalarVar(tp,
-          isLhs: isLhs, rhsFilter: rhsFilter); // resort to scalar
+      ret = emitScalarVar(
+        tp,
+        isLhs: isLhs,
+        rhsFilter: rhsFilter,
+      ); // resort to scalar
     }
     return ret;
   }
 
-  String? emitVar(int depth, DartType tp,
-      {bool isLhs = false, String? assignOp, RhsFilter? rhsFilter}) {
+  String? emitVar(
+    int depth,
+    DartType tp, {
+    bool isLhs = false,
+    String? assignOp,
+    RhsFilter? rhsFilter,
+  }) {
     switch (choose(2)) {
       case 0:
         return emitScalarVar(tp, isLhs: isLhs, rhsFilter: rhsFilter);
       default:
-        return emitSubscriptedVar(depth, tp,
-            isLhs: isLhs, assignOp: assignOp, rhsFilter: rhsFilter);
+        return emitSubscriptedVar(
+          depth,
+          tp,
+          isLhs: isLhs,
+          assignOp: assignOp,
+          rhsFilter: rhsFilter,
+        );
     }
   }
 
@@ -1976,7 +2299,8 @@
       emit(oneOfSet(dartType.uniOps(tp)));
       var uniOpParam = tp.toNonNullable();
       emitParenWrapped(
-          () => emitExpr(depth + 1, uniOpParam, rhsFilter: rhsFilter));
+        () => emitExpr(depth + 1, uniOpParam, rhsFilter: rhsFilter),
+      );
     });
   }
 
@@ -2059,8 +2383,12 @@
   }
 
   // Emit library call.
-  void emitLibraryCall(int depth, DartType tp,
-      {RhsFilter? rhsFilter, bool includeSemicolon = false}) {
+  void emitLibraryCall(
+    int depth,
+    DartType tp, {
+    RhsFilter? rhsFilter,
+    bool includeSemicolon = false,
+  }) {
     var lib = getLibraryMethod(tp);
     if (lib == null || (!fp && isTypedDataFloatType(lib.proto))) {
       // We cannot find a library method, or we found a library method but its
@@ -2074,9 +2402,14 @@
       var prototype = lib.proto;
       // Receiver.
       if (prototype[0] != DartType.VOID) {
-        emitParenWrapped(() => emitArg(
-            depth + 1, prototype[0], lib.getRestriction(0),
-            rhsFilter: rhsFilter));
+        emitParenWrapped(
+          () => emitArg(
+            depth + 1,
+            prototype[0],
+            lib.getRestriction(0),
+            rhsFilter: rhsFilter,
+          ),
+        );
         emit('.');
       }
       // Call.
@@ -2086,11 +2419,15 @@
         emitParenWrapped(() {
           if (prototype[1] != DartType.VOID) {
             emitCommaSeparated(
-                (int i) => emitArg(
-                    depth + 1, prototype[i], lib.getRestriction(i),
-                    rhsFilter: rhsFilter),
-                prototype.length,
-                start: 1);
+              (int i) => emitArg(
+                depth + 1,
+                prototype[i],
+                lib.getRestriction(i),
+                rhsFilter: rhsFilter,
+              ),
+              prototype.length,
+              start: 1,
+            );
           }
         });
       }
@@ -2105,16 +2442,24 @@
   }
 
   // Helper for a method call.
-  bool pickedCall(int depth, DartType tp, List<Method> methods, int m,
-      {RhsFilter? rhsFilter}) {
+  bool pickedCall(
+    int depth,
+    DartType tp,
+    List<Method> methods,
+    int m, {
+    RhsFilter? rhsFilter,
+  }) {
     for (var i = m - 1; i >= 0; i--) {
       if (tp == methods[i].returnType) {
         var isRecursiveCall = (currentMethod == methods[i]);
         if (isRecursiveCall && !methods[i].recursionAllowed) {
           continue;
         }
-        methods[i].emitCall(depth + 1,
-            rhsFilter: rhsFilter, isRecursiveCall: isRecursiveCall);
+        methods[i].emitCall(
+          depth + 1,
+          rhsFilter: rhsFilter,
+          isRecursiveCall: isRecursiveCall,
+        );
         return true;
       }
     }
@@ -2127,8 +2472,13 @@
     if (currentClassIndex == null) {
       // Outside a class but inside a method: call backward in global methods.
       if (currentMethodIndex != null &&
-          pickedCall(depth, tp, globalMethods, currentMethodIndex! + 1,
-              rhsFilter: rhsFilter)) {
+          pickedCall(
+            depth,
+            tp,
+            globalMethods,
+            currentMethodIndex! + 1,
+            rhsFilter: rhsFilter,
+          )) {
         return;
       }
     } else {
@@ -2155,8 +2505,13 @@
         m1 = currentMethodIndex! + 1;
       }
       final m2 = globalMethods.length;
-      if (pickedCall(depth, tp, classMethods[classIndex], m1,
-              rhsFilter: rhsFilter) ||
+      if (pickedCall(
+            depth,
+            tp,
+            classMethods[classIndex],
+            m1,
+            rhsFilter: rhsFilter,
+          ) ||
           pickedCall(depth, tp, globalMethods, m2, rhsFilter: rhsFilter)) {
         return;
       }
@@ -2165,8 +2520,12 @@
   }
 
   // Emit expression.
-  void emitExpr(int depth, DartType tp,
-      {RhsFilter? rhsFilter, bool includeSemicolon = false}) {
+  void emitExpr(
+    int depth,
+    DartType tp, {
+    RhsFilter? rhsFilter,
+    bool includeSemicolon = false,
+  }) {
     final resetExprStmt = processExprOpen(tp);
     // Continuing nested expressions becomes less likely as the depth grows.
     if (choose(depth + 1) > exprDepth) {
@@ -2187,8 +2546,11 @@
           emitPreOrPostExpr(depth, tp, rhsFilter: rhsFilter);
           break;
         case 4:
-          emitLibraryCall(depth, tp,
-              rhsFilter: RhsFilter.cloneEmpty(rhsFilter));
+          emitLibraryCall(
+            depth,
+            tp,
+            rhsFilter: RhsFilter.cloneEmpty(rhsFilter),
+          );
           break;
         case 5:
           emitMethodCall(depth, tp, rhsFilter: RhsFilter.cloneEmpty(rhsFilter));
@@ -2234,8 +2596,12 @@
           : null;
 
   // Emit a library argument, possibly subject to restrictions.
-  void emitArg(int depth, DartType type, Restriction restriction,
-      {RhsFilter? rhsFilter}) {
+  void emitArg(
+    int depth,
+    DartType type,
+    Restriction restriction, {
+    RhsFilter? rhsFilter,
+  }) {
     if ((type == DartType.INT) && (restriction == Restriction.small)) {
       emitSmallPositiveInt();
     } else if ((type == DartType.DOUBLE) && !fp) {
@@ -2265,8 +2631,11 @@
     return list;
   }
 
-  List<List<DartType>> fillTypes2(
-      {bool isFfi = false, int limit2 = 4, int limit1 = 4}) {
+  List<List<DartType>> fillTypes2({
+    bool isFfi = false,
+    int limit2 = 4,
+    int limit1 = 4,
+  }) {
     final list = <List<DartType>>[];
     for (var i = 0, n = chooseOneUpTo(limit2); i < n; i++) {
       list.add(fillTypes1(limit: limit1, isFfi: isFfi));
@@ -2294,8 +2663,14 @@
 
   void emitFfiType(DartType tp) {
     if (tp == DartType.INT) {
-      emit(oneOf(
-          const <String>['ffi.Int8', 'ffi.Int16', 'ffi.Int32', 'ffi.Int64']));
+      emit(
+        oneOf(const <String>[
+          'ffi.Int8',
+          'ffi.Int16',
+          'ffi.Int32',
+          'ffi.Int64',
+        ]),
+      );
     } else if (tp == DartType.DOUBLE) {
       emit(oneOf(const <String>['ffi.Float', 'ffi.Double']));
     } else {
@@ -2309,9 +2684,13 @@
     emitFfiType(pars[0]);
     emit(' Function');
     emitParenWrapped(
-        () => emitCommaSeparated((int i) => emitFfiType(pars[i]), pars.length,
-            start: 1),
-        includeSemicolon: true);
+      () => emitCommaSeparated(
+        (int i) => emitFfiType(pars[i]),
+        pars.length,
+        start: 1,
+      ),
+      includeSemicolon: true,
+    );
     emitNewline();
     emitNewline();
   }
@@ -2459,7 +2838,7 @@
     0xffffffff7fffffff,
     0xffffffff80000000,
     0xffffffff80000001,
-    0xffffffffffffffff
+    0xffffffffffffffff,
   ];
 }
 
@@ -2486,25 +2865,48 @@
   const kMini = 'mini';
   const kSMask = 'smask';
   const kEMask = 'emask';
-  final parser = ArgParser()
-    ..addOption(kSeed,
-        help: 'random seed (0 forces time-based seed)', defaultsTo: '0')
-    ..addFlag(kFp, help: 'enables floating-point operations', defaultsTo: true)
-    ..addFlag(kFfi,
-        help: 'enables FFI method calls (default: off)', defaultsTo: false)
-    ..addFlag(kFlat,
-        help: 'enables flat types (default: off)', defaultsTo: false)
-    // Minimization mode extensions.
-    ..addFlag(kMini,
-        help: 'enables minimization mode (default: off)', defaultsTo: false)
-    ..addOption(kSMask,
-        help: 'Bitmask indicating which statements to omit'
-            '(Bit=1 omits)',
-        defaultsTo: '0')
-    ..addOption(kEMask,
-        help: 'Bitmask indicating which expressions to omit'
-            '(Bit=1 omits)',
-        defaultsTo: '0');
+  final parser =
+      ArgParser()
+        ..addOption(
+          kSeed,
+          help: 'random seed (0 forces time-based seed)',
+          defaultsTo: '0',
+        )
+        ..addFlag(
+          kFp,
+          help: 'enables floating-point operations',
+          defaultsTo: true,
+        )
+        ..addFlag(
+          kFfi,
+          help: 'enables FFI method calls (default: off)',
+          defaultsTo: false,
+        )
+        ..addFlag(
+          kFlat,
+          help: 'enables flat types (default: off)',
+          defaultsTo: false,
+        )
+        // Minimization mode extensions.
+        ..addFlag(
+          kMini,
+          help: 'enables minimization mode (default: off)',
+          defaultsTo: false,
+        )
+        ..addOption(
+          kSMask,
+          help:
+              'Bitmask indicating which statements to omit'
+              '(Bit=1 omits)',
+          defaultsTo: '0',
+        )
+        ..addOption(
+          kEMask,
+          help:
+              'Bitmask indicating which expressions to omit'
+              '(Bit=1 omits)',
+          defaultsTo: '0',
+        );
   final ArgResults results;
   try {
     results = parser.parse(arguments);
@@ -2521,8 +2923,16 @@
   final minimize = results[kMini];
   final smask = BigInt.parse(results[kSMask]);
   final emask = BigInt.parse(results[kEMask]);
-  final dartFuzz = DartFuzz(seed, fp, ffi, flatTp, file,
-      minimize: minimize, smask: smask, emask: emask);
+  final dartFuzz = DartFuzz(
+    seed,
+    fp,
+    ffi,
+    flatTp,
+    file,
+    minimize: minimize,
+    smask: smask,
+    emask: emask,
+  );
   dartFuzz.run();
   file.closeSync();
   // Print information that will be parsed by minimize.py
diff --git a/runtime/tools/dartfuzz/minimize.py b/runtime/tools/dartfuzz/minimize.py
index c9be86a..a54e440 100755
--- a/runtime/tools/dartfuzz/minimize.py
+++ b/runtime/tools/dartfuzz/minimize.py
@@ -139,7 +139,7 @@
         p = subprocess.Popen(cmds, stdout=subprocess.PIPE)
     p_stdout, p_stderr = p.communicate()
     if p.returncode != 0:
-        raise 'Invalid return code on generate %d' % p.returncode
+        raise RuntimeError('Invalid return code on generate %d' % p.returncode)
     mask_new = 0
     if do_expr:
         mask_new = int(p_stdout.decode().splitlines()[EXPRESSION_MASK_LINE])