diff --git a/pkg/front_end/lib/src/fasta/kernel/constant_evaluator.dart b/pkg/front_end/lib/src/fasta/kernel/constant_evaluator.dart
index 6d4b8d9b7dd..19ac28d4f28 100644
--- a/pkg/front_end/lib/src/fasta/kernel/constant_evaluator.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/constant_evaluator.dart
@@ -1587,8 +1587,8 @@ class ConstantsTransformer extends RemovingTransformer {
       }
     }
     if (_exhaustivenessDataForTesting != null) {
-      _exhaustivenessDataForTesting!.objectFieldLookup ??= _exhaustivenessCache;
-      _exhaustivenessDataForTesting!.switchResults[replacement] =
+      _exhaustivenessDataForTesting.objectFieldLookup ??= _exhaustivenessCache;
+      _exhaustivenessDataForTesting.switchResults[replacement] =
           new ExhaustivenessResult(type, cases,
               patternGuards.map((c) => c.fileOffset).toList(), reportedErrors!);
     }
@@ -1826,10 +1826,9 @@ class ConstantsTransformer extends RemovingTransformer {
       // [PatternAssignment]s for effect.
       if (_exhaustivenessDataForTesting != null) {
         ExhaustivenessResult? result =
-            _exhaustivenessDataForTesting!.switchResults[expression];
+            _exhaustivenessDataForTesting.switchResults[expression];
         if (result != null) {
-          _exhaustivenessDataForTesting!.switchResults[expression.body] =
-              result;
+          _exhaustivenessDataForTesting.switchResults[expression.body] = result;
         }
       }
       return expression.body;
@@ -5849,7 +5848,7 @@ class EvaluationEnvironment {
   bool get isEmpty {
     // Since we look up variables in enclosing environment, the environment
     // is not empty if its parent is not empty.
-    if (_parent != null && !_parent!.isEmpty) return false;
+    if (_parent != null && !_parent.isEmpty) return false;
     return _typeVariables.isEmpty && _variables.isEmpty;
   }
 
@@ -5897,7 +5896,7 @@ class EvaluationEnvironment {
     final DartType substitutedType = substitute(type, _typeVariables);
     if (identical(substitutedType, type) && _parent != null) {
       // No distinct type created, substitute type in parent.
-      return _parent!.substituteType(type);
+      return _parent.substituteType(type);
     }
     return substitutedType;
   }
diff --git a/pkg/front_end/lib/src/fasta/kernel/forwarding_node.dart b/pkg/front_end/lib/src/fasta/kernel/forwarding_node.dart
index 7df14777f4f..c420dfad17b 100644
--- a/pkg/front_end/lib/src/fasta/kernel/forwarding_node.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/forwarding_node.dart
@@ -102,7 +102,7 @@ class ForwardingNode {
     bool hasValidImplementation = false;
     if (_superClassMember != null) {
       superTarget =
-          _superClassMember!.getMember(_combinedMemberSignature.membersBuilder);
+          _superClassMember.getMember(_combinedMemberSignature.membersBuilder);
       if (superTarget is Procedure &&
           interfaceMember is Procedure &&
           (superTarget.function.positionalParameters.length <
@@ -148,7 +148,7 @@ class ForwardingNode {
         } else {
           // [superTarget] is a valid implementation for [interfaceMember] so
           // we need to add concrete forwarding stub of the variances differ.
-          needsSuperImpl = _superClassMember!
+          needsSuperImpl = _superClassMember
                   .getCovariance(_combinedMemberSignature.membersBuilder) !=
               _combinedMemberSignature.combinedMemberSignatureCovariance;
           hasValidImplementation = true;
@@ -202,9 +202,8 @@ class ForwardingNode {
         if (needsNoSuchMethodForwarder) {
           _createNoSuchMethodForwarder(
               classBuilder,
-              _noSuchMethodTarget!
-                      .getMember(_combinedMemberSignature.membersBuilder)
-                  as Procedure,
+              _noSuchMethodTarget.getMember(
+                  _combinedMemberSignature.membersBuilder) as Procedure,
               stub);
         } else if (needsSuperImpl ||
             (needMixinStub && _superClassMember == _mixedInMember)) {
@@ -228,9 +227,8 @@ class ForwardingNode {
         interfaceMember.stubTarget = null;
         _createNoSuchMethodForwarder(
             classBuilder,
-            _noSuchMethodTarget!
-                    .getMember(_combinedMemberSignature.membersBuilder)
-                as Procedure,
+            _noSuchMethodTarget.getMember(
+                _combinedMemberSignature.membersBuilder) as Procedure,
             interfaceMember);
       } else if (needsSuperImpl) {
         _createForwardingImplIfNeeded(interfaceMember.function!,
@@ -280,7 +278,7 @@ class ForwardingNode {
                   type.typeParameters,
                   function.typeParameters
                       .map((TypeParameter parameter) => new TypeParameterType
-                              .withDefaultNullabilityForLibrary(
+                          .withDefaultNullabilityForLibrary(
                           parameter, procedure.enclosingLibrary))
                       .toList())
               .substituteType(type.withoutTypeParameters) as FunctionType;
diff --git a/pkg/front_end/lib/src/fasta/kernel/hierarchy/class_member.dart b/pkg/front_end/lib/src/fasta/kernel/hierarchy/class_member.dart
index da6fdef85bf..9ed9b5dd370 100644
--- a/pkg/front_end/lib/src/fasta/kernel/hierarchy/class_member.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/hierarchy/class_member.dart
@@ -323,8 +323,8 @@ class SynthesizedInterfaceMember extends SynthesizedMember {
     }
     if (classBuilder.libraryBuilder is! SourceLibraryBuilder) {
       if (_canonicalMember != null) {
-        _member = _canonicalMember!.getMember(membersBuilder);
-        _covariance = _canonicalMember!.getCovariance(membersBuilder);
+        _member = _canonicalMember.getMember(membersBuilder);
+        _covariance = _canonicalMember.getCovariance(membersBuilder);
       } else {
         _member = declarations.first.getMember(membersBuilder);
         _covariance = declarations.first.getCovariance(membersBuilder);
@@ -336,7 +336,7 @@ class SynthesizedInterfaceMember extends SynthesizedMember {
       combinedMemberSignature = new CombinedClassMemberSignature.internal(
           membersBuilder,
           classBuilder as SourceClassBuilder,
-          declarations.indexOf(_canonicalMember!),
+          declarations.indexOf(_canonicalMember),
           declarations,
           forSetter: isSetter);
     } else {
diff --git a/pkg/front_end/lib/src/fasta/kernel/member_covariance.dart b/pkg/front_end/lib/src/fasta/kernel/member_covariance.dart
index f87f1806c2a..24fffa80ec0 100644
--- a/pkg/front_end/lib/src/fasta/kernel/member_covariance.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/member_covariance.dart
@@ -64,12 +64,12 @@ class Covariance {
   Covariance.internal(
       this._positionalParameters, this._namedParameters, this._typeParameters) {
     assert(_positionalParameters == null ||
-        _positionalParameters!.any((element) => element != 0));
+        _positionalParameters.any((element) => element != 0));
     assert(_namedParameters == null ||
-        _namedParameters!.values.isNotEmpty &&
-            _namedParameters!.values.every((element) => element != 0));
+        _namedParameters.values.isNotEmpty &&
+            _namedParameters.values.every((element) => element != 0));
     assert(
-        _typeParameters == null || _typeParameters!.any((element) => element));
+        _typeParameters == null || _typeParameters.any((element) => element));
   }
 
   /// The empty covariance.
@@ -214,8 +214,7 @@ class Covariance {
       positionalParameters = _positionalParameters;
     } else {
       positionalParameters = new List<int>.filled(
-          max(_positionalParameters!.length,
-              other._positionalParameters!.length),
+          max(_positionalParameters.length, other._positionalParameters.length),
           0);
       for (int index = 0; index < positionalParameters.length; index++) {
         positionalParameters[index] =
@@ -230,8 +229,8 @@ class Covariance {
     } else {
       namedParameters = {};
       Set<String> names = {
-        ..._namedParameters!.keys,
-        ...other._namedParameters!.keys
+        ..._namedParameters.keys,
+        ...other._namedParameters.keys
       };
       for (String name in names) {
         namedParameters[name] =
@@ -245,7 +244,7 @@ class Covariance {
       typeParameters = _typeParameters;
     } else {
       typeParameters = new List<bool>.filled(
-          max(_typeParameters!.length, other._typeParameters!.length), false);
+          max(_typeParameters.length, other._typeParameters.length), false);
       for (int index = 0; index < typeParameters.length; index++) {
         typeParameters[index] = isTypeParameterGenericCovariantImpl(index) ||
             other.isTypeParameterGenericCovariantImpl(index);
@@ -338,7 +337,7 @@ class Covariance {
           return false;
         }
         int positionalParameterCount = max(
-            _positionalParameters!.length, other._positionalParameters!.length);
+            _positionalParameters.length, other._positionalParameters.length);
         for (int i = 0; i < positionalParameterCount; i++) {
           if (getPositionalVariance(i) != other.getPositionalVariance(i)) {
             return false;
@@ -350,8 +349,8 @@ class Covariance {
           return false;
         }
         Set<String> names = {
-          ..._namedParameters!.keys,
-          ...other._namedParameters!.keys
+          ..._namedParameters.keys,
+          ...other._namedParameters.keys
         };
         for (String name in names) {
           if (getNamedVariance(name) != other.getNamedVariance(name)) {
@@ -364,7 +363,7 @@ class Covariance {
           return false;
         }
         int typeParameterCount =
-            max(_typeParameters!.length, other._typeParameters!.length);
+            max(_typeParameters.length, other._typeParameters.length);
         for (int i = 0; i < typeParameterCount; i++) {
           if (isTypeParameterGenericCovariantImpl(i) !=
               other.isTypeParameterGenericCovariantImpl(i)) {
diff --git a/pkg/front_end/lib/src/fasta/source/source_constructor_builder.dart b/pkg/front_end/lib/src/fasta/source/source_constructor_builder.dart
index eeb8b85900f..4809b7730c6 100644
--- a/pkg/front_end/lib/src/fasta/source/source_constructor_builder.dart
+++ b/pkg/front_end/lib/src/fasta/source/source_constructor_builder.dart
@@ -493,7 +493,7 @@ class DeclaredSourceConstructorBuilder
 
       if (_constructorTearOff != null) {
         buildConstructorTearOffProcedure(
-            tearOff: _constructorTearOff!,
+            tearOff: _constructorTearOff,
             declarationConstructor: constructor,
             implementationConstructor: _constructor,
             enclosingDeclarationTypeParameters: classBuilder.cls.typeParameters,
@@ -720,7 +720,7 @@ class DeclaredSourceConstructorBuilder
             libraryBuilder: libraryBuilder));
         if (_constructorTearOff != null) {
           delayedDefaultValueCloners.add(new DelayedDefaultValueCloner(
-              superTarget, _constructorTearOff!, substitution,
+              superTarget, _constructorTearOff, substitution,
               positionalSuperParameters:
                   positionalSuperParameters ?? const <int>[],
               namedSuperParameters: namedSuperParameters ?? const <String>[],
@@ -822,12 +822,12 @@ class DeclaredSourceConstructorBuilder
   @override
   VariableDeclaration? getTearOffParameter(int index) {
     if (_constructorTearOff != null) {
-      if (index < _constructorTearOff!.function.positionalParameters.length) {
-        return _constructorTearOff!.function.positionalParameters[index];
+      if (index < _constructorTearOff.function.positionalParameters.length) {
+        return _constructorTearOff.function.positionalParameters[index];
       } else {
-        index -= _constructorTearOff!.function.positionalParameters.length;
-        if (index < _constructorTearOff!.function.namedParameters.length) {
-          return _constructorTearOff!.function.namedParameters[index];
+        index -= _constructorTearOff.function.positionalParameters.length;
+        if (index < _constructorTearOff.function.namedParameters.length) {
+          return _constructorTearOff.function.namedParameters[index];
         }
       }
     }
@@ -838,7 +838,7 @@ class DeclaredSourceConstructorBuilder
     finishConstructorPatch(origin.constructor, _constructor);
 
     if (_constructorTearOff != null) {
-      finishProcedurePatch(origin._constructorTearOff!, _constructorTearOff!);
+      finishProcedurePatch(origin._constructorTearOff!, _constructorTearOff);
     }
   }
 
@@ -1219,7 +1219,7 @@ class SourceExtensionTypeConstructorBuilder
 
       if (_constructorTearOff != null) {
         buildConstructorTearOffProcedure(
-            tearOff: _constructorTearOff!,
+            tearOff: _constructorTearOff,
             declarationConstructor: _constructor,
             implementationConstructor: _constructor,
             libraryBuilder: libraryBuilder);
diff --git a/pkg/front_end/lib/src/fasta/source/source_factory_builder.dart b/pkg/front_end/lib/src/fasta/source/source_factory_builder.dart
index 76937160ed9..c23f83490ae 100644
--- a/pkg/front_end/lib/src/fasta/source/source_factory_builder.dart
+++ b/pkg/front_end/lib/src/fasta/source/source_factory_builder.dart
@@ -179,7 +179,7 @@ class SourceFactoryBuilder extends SourceFunctionBuilderImpl {
 
     if (_factoryTearOff != null) {
       buildConstructorTearOffProcedure(
-          tearOff: _factoryTearOff!,
+          tearOff: _factoryTearOff,
           declarationConstructor: _procedure,
           implementationConstructor: _procedureInternal,
           libraryBuilder: libraryBuilder);
@@ -202,12 +202,12 @@ class SourceFactoryBuilder extends SourceFunctionBuilderImpl {
   @override
   VariableDeclaration? getTearOffParameter(int index) {
     if (_factoryTearOff != null) {
-      if (index < _factoryTearOff!.function.positionalParameters.length) {
-        return _factoryTearOff!.function.positionalParameters[index];
+      if (index < _factoryTearOff.function.positionalParameters.length) {
+        return _factoryTearOff.function.positionalParameters[index];
       } else {
-        index -= _factoryTearOff!.function.positionalParameters.length;
-        if (index < _factoryTearOff!.function.namedParameters.length) {
-          return _factoryTearOff!.function.namedParameters[index];
+        index -= _factoryTearOff.function.positionalParameters.length;
+        if (index < _factoryTearOff.function.namedParameters.length) {
+          return _factoryTearOff.function.namedParameters[index];
         }
       }
     }
@@ -259,7 +259,7 @@ class SourceFactoryBuilder extends SourceFunctionBuilderImpl {
     finishProcedurePatch(origin._procedure, _procedureInternal);
 
     if (_factoryTearOff != null) {
-      finishProcedurePatch(origin._factoryTearOff!, _factoryTearOff!);
+      finishProcedurePatch(origin._factoryTearOff!, _factoryTearOff);
     }
   }
 
@@ -409,9 +409,8 @@ class RedirectingFactoryBuilder extends SourceFactoryBuilder {
     _procedure.function.redirectingFactoryTarget =
         new RedirectingFactoryTarget.error(message);
     if (_factoryTearOff != null) {
-      _factoryTearOff!.function.body =
-          createRedirectingFactoryErrorBody(message)
-            ..parent = _factoryTearOff!.function;
+      _factoryTearOff.function.body = createRedirectingFactoryErrorBody(message)
+        ..parent = _factoryTearOff.function;
     }
   }
 
@@ -446,7 +445,7 @@ class RedirectingFactoryBuilder extends SourceFactoryBuilder {
     if (_factoryTearOff != null) {
       _tearOffTypeParameters =
           buildRedirectingFactoryTearOffProcedureParameters(
-              tearOff: _factoryTearOff!,
+              tearOff: _factoryTearOff,
               implementationConstructor: _procedureInternal,
               libraryBuilder: libraryBuilder);
     }
@@ -543,7 +542,7 @@ class RedirectingFactoryBuilder extends SourceFactoryBuilder {
       typeArguments ??= [];
       if (_factoryTearOff != null) {
         delayedDefaultValueCloners.add(buildRedirectingFactoryTearOffBody(
-            _factoryTearOff!,
+            _factoryTearOff,
             target!,
             typeArguments,
             _tearOffTypeParameters!,
diff --git a/pkg/front_end/lib/src/fasta/source/source_library_builder.dart b/pkg/front_end/lib/src/fasta/source/source_library_builder.dart
index 1a0b24b11f1..e66e16d6248 100644
--- a/pkg/front_end/lib/src/fasta/source/source_library_builder.dart
+++ b/pkg/front_end/lib/src/fasta/source/source_library_builder.dart
@@ -332,7 +332,7 @@ class SourceLibraryBuilder extends LibraryBuilderImpl {
     assert(
         _packageUri == null ||
             !importUri.isScheme('package') ||
-            importUri.path.startsWith(_packageUri!.path),
+            importUri.path.startsWith(_packageUri.path),
         "Foreign package uri '$_packageUri' set on library with import uri "
         "'${importUri}'.");
     assert(
@@ -1753,7 +1753,7 @@ class SourceLibraryBuilder extends LibraryBuilderImpl {
       List<TypeBuilder>? arguments, int charOffset,
       {required InstanceTypeVariableAccessState instanceTypeVariableAccess}) {
     if (_omittedTypeDeclarationBuilders != null) {
-      Builder? builder = _omittedTypeDeclarationBuilders![name];
+      Builder? builder = _omittedTypeDeclarationBuilders[name];
       if (builder is OmittedTypeDeclarationBuilder) {
         return new DependentTypeBuilder(builder.omittedTypeBuilder);
       }
diff --git a/pkg/front_end/lib/src/fasta/source/source_type_alias_builder.dart b/pkg/front_end/lib/src/fasta/source/source_type_alias_builder.dart
index 43cf2832173..38aa4bb3f33 100644
--- a/pkg/front_end/lib/src/fasta/source/source_type_alias_builder.dart
+++ b/pkg/front_end/lib/src/fasta/source/source_type_alias_builder.dart
@@ -145,7 +145,7 @@ class SourceTypeAliasBuilder extends TypeAliasBuilderImpl {
         // bounds should have been assigned.
         libraryBuilder.registerPendingNullability(
             _typeVariables![i].fileUri!,
-            _typeVariables![i].charOffset,
+            _typeVariables[i].charOffset,
             asTypeArguments[i] as TypeParameterType);
       }
     }
diff --git a/pkg/front_end/lib/src/fasta/type_inference/delayed_expressions.dart b/pkg/front_end/lib/src/fasta/type_inference/delayed_expressions.dart
index f0de7d70a2a..9252ac105b0 100644
--- a/pkg/front_end/lib/src/fasta/type_inference/delayed_expressions.dart
+++ b/pkg/front_end/lib/src/fasta/type_inference/delayed_expressions.dart
@@ -439,7 +439,7 @@ class EffectExpression implements DelayedExpression {
       identical(this, expression) ||
       _effect.uses(expression) ||
       _result.uses(expression) ||
-      (_lateEffect != null && _lateEffect!.uses(expression));
+      (_lateEffect != null && _lateEffect.uses(expression));
 
   @override
   bool get isEffectOnly => _result.isEffectOnly;
@@ -452,9 +452,9 @@ class EffectExpression implements DelayedExpression {
     _result.createStatements(typeEnvironment, results, effects: effects);
     if (_lateEffect != null) {
       if (effects != null) {
-        _lateEffect!.createStatements(typeEnvironment, effects);
+        _lateEffect.createStatements(typeEnvironment, effects);
       } else {
-        _lateEffect!.createStatements(typeEnvironment, results);
+        _lateEffect.createStatements(typeEnvironment, results);
       }
     }
   }
diff --git a/pkg/front_end/pubspec.yaml b/pkg/front_end/pubspec.yaml
index 133ef800b5b..a200a641f6d 100644
--- a/pkg/front_end/pubspec.yaml
+++ b/pkg/front_end/pubspec.yaml
@@ -6,7 +6,7 @@ name: front_end
 publish_to: none
 
 environment:
-  sdk: ^3.0.0
+  sdk: ^3.2.0-0
 
 # Use 'any' constraints here; we get our versions from the DEPS file.
 dependencies:
diff --git a/pkg/front_end/test/fasta/type_inference/type_schema_test.dart b/pkg/front_end/test/fasta/type_inference/type_schema_test.dart
index 1f36bba05d0..1a2ac4f79d5 100644
--- a/pkg/front_end/test/fasta/type_inference/type_schema_test.dart
+++ b/pkg/front_end/test/fasta/type_inference/type_schema_test.dart
@@ -119,7 +119,7 @@ class _OrdinaryVisitor<R> extends VisitorDefault<R?> with VisitorNullMixin<R> {
   @override
   R? defaultDartType(DartType node) {
     if (_defaultDartType != null) {
-      return _defaultDartType!(node);
+      return _defaultDartType(node);
     } else {
       return super.defaultDartType(node);
     }
@@ -140,9 +140,9 @@ class _TypeSchemaVisitor<R> extends VisitorDefault<R?>
   @override
   R? defaultDartType(DartType node) {
     if (node is UnknownType && _visitUnknownType != null) {
-      return _visitUnknownType!(node);
+      return _visitUnknownType(node);
     } else if (_defaultDartType != null) {
-      return _defaultDartType!(node);
+      return _defaultDartType(node);
     } else {
       return super.defaultDartType(node);
     }
diff --git a/pkg/front_end/test/static_types/verifying_analysis.dart b/pkg/front_end/test/static_types/verifying_analysis.dart
index 4305459f1e2..28678affc47 100644
--- a/pkg/front_end/test/static_types/verifying_analysis.dart
+++ b/pkg/front_end/test/static_types/verifying_analysis.dart
@@ -25,7 +25,7 @@ class VerifyingAnalysis extends AnalysisVisitor {
 
   void run({bool verbose = false, bool generate = false}) {
     if (!generate && _allowedListPath != null) {
-      File file = new File(_allowedListPath!);
+      File file = new File(_allowedListPath);
       if (file.existsSync()) {
         try {
           _expectedJson = json.jsonDecode(file.readAsStringSync());
@@ -47,7 +47,7 @@ class VerifyingAnalysis extends AnalysisVisitor {
         actualJson[uri] = map;
       });
 
-      new File(_allowedListPath!).writeAsStringSync(
+      new File(_allowedListPath).writeAsStringSync(
           new json.JsonEncoder.withIndent('  ').convert(actualJson));
       return;
     }