diff --git a/pkg/dart2js_info/bin/src/debug_info.dart b/pkg/dart2js_info/bin/src/debug_info.dart
index 6199ee4..1de2f7d 100644
--- a/pkg/dart2js_info/bin/src/debug_info.dart
+++ b/pkg/dart2js_info/bin/src/debug_info.dart
@@ -194,7 +194,7 @@
       _debugCode.write(' ' * _indent);
       var endsInNewLine = code.endsWith('\n');
       if (endsInNewLine) code = code.substring(0, code.length - 1);
-      _debugCode.write(code.replaceAll('\n', '\n' + (' ' * _indent)));
+      _debugCode.write(code.replaceAll('\n', '\n${' ' * _indent}'));
       if (endsInNewLine) _debugCode.write(',\n');
       if (isClosureClass) {
         _indent -= 2;
diff --git a/pkg/dart2js_info/bin/src/library_size_split.dart b/pkg/dart2js_info/bin/src/library_size_split.dart
index da6d85d..1721457 100644
--- a/pkg/dart2js_info/bin/src/library_size_split.dart
+++ b/pkg/dart2js_info/bin/src/library_size_split.dart
@@ -138,7 +138,7 @@
 
     _printRow(_Row row) {
       if (row is _Divider) {
-        print(' ' + ('-' * (longest + 18)));
+        print(' ${'-' * (longest + 18)}');
         return;
       }
 
diff --git a/pkg/dart2js_info/lib/src/proto/info.pb.dart b/pkg/dart2js_info/lib/src/proto/info.pb.dart
index 28d20a6..6d56230 100644
--- a/pkg/dart2js_info/lib/src/proto/info.pb.dart
+++ b/pkg/dart2js_info/lib/src/proto/info.pb.dart
@@ -37,14 +37,14 @@
     $core.String? targetId,
     $core.String? mask,
   }) {
-    final _result = create();
+    final result = create();
     if (targetId != null) {
-      _result.targetId = targetId;
+      result.targetId = targetId;
     }
     if (mask != null) {
-      _result.mask = mask;
+      result.mask = mask;
     }
-    return _result;
+    return result;
   }
   factory DependencyInfoPB.fromBuffer($core.List<$core.int> i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
@@ -139,17 +139,17 @@
     $core.Map<$core.String, InfoPB>? allInfos,
     $core.Iterable<LibraryDeferredImportsPB>? deferredImports,
   }) {
-    final _result = create();
+    final result = create();
     if (program != null) {
-      _result.program = program;
+      result.program = program;
     }
     if (allInfos != null) {
-      _result.allInfos.addAll(allInfos);
+      result.allInfos.addAll(allInfos);
     }
     if (deferredImports != null) {
-      _result.deferredImports.addAll(deferredImports);
+      result.deferredImports.addAll(deferredImports);
     }
-    return _result;
+    return result;
   }
   factory AllInfoPB.fromBuffer($core.List<$core.int> i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
@@ -354,59 +354,59 @@
     ClosureInfoPB? closureInfo,
     ClassTypeInfoPB? classTypeInfo,
   }) {
-    final _result = create();
+    final result = create();
     if (name != null) {
-      _result.name = name;
+      result.name = name;
     }
     if (id != null) {
-      _result.id = id;
+      result.id = id;
     }
     if (serializedId != null) {
-      _result.serializedId = serializedId;
+      result.serializedId = serializedId;
     }
     if (coverageId != null) {
-      _result.coverageId = coverageId;
+      result.coverageId = coverageId;
     }
     if (size != null) {
-      _result.size = size;
+      result.size = size;
     }
     if (parentId != null) {
-      _result.parentId = parentId;
+      result.parentId = parentId;
     }
     if (uses != null) {
-      _result.uses.addAll(uses);
+      result.uses.addAll(uses);
     }
     if (outputUnitId != null) {
-      _result.outputUnitId = outputUnitId;
+      result.outputUnitId = outputUnitId;
     }
     if (libraryInfo != null) {
-      _result.libraryInfo = libraryInfo;
+      result.libraryInfo = libraryInfo;
     }
     if (classInfo != null) {
-      _result.classInfo = classInfo;
+      result.classInfo = classInfo;
     }
     if (functionInfo != null) {
-      _result.functionInfo = functionInfo;
+      result.functionInfo = functionInfo;
     }
     if (fieldInfo != null) {
-      _result.fieldInfo = fieldInfo;
+      result.fieldInfo = fieldInfo;
     }
     if (constantInfo != null) {
-      _result.constantInfo = constantInfo;
+      result.constantInfo = constantInfo;
     }
     if (outputUnitInfo != null) {
-      _result.outputUnitInfo = outputUnitInfo;
+      result.outputUnitInfo = outputUnitInfo;
     }
     if (typedefInfo != null) {
-      _result.typedefInfo = typedefInfo;
+      result.typedefInfo = typedefInfo;
     }
     if (closureInfo != null) {
-      _result.closureInfo = closureInfo;
+      result.closureInfo = closureInfo;
     }
     if (classTypeInfo != null) {
-      _result.classTypeInfo = classTypeInfo;
+      result.classTypeInfo = classTypeInfo;
     }
-    return _result;
+    return result;
   }
   factory InfoPB.fromBuffer($core.List<$core.int> i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
@@ -745,47 +745,47 @@
     $core.bool? isMirrorsUsed,
     $core.bool? minified,
   }) {
-    final _result = create();
+    final result = create();
     if (entrypointId != null) {
-      _result.entrypointId = entrypointId;
+      result.entrypointId = entrypointId;
     }
     if (size != null) {
-      _result.size = size;
+      result.size = size;
     }
     if (dart2jsVersion != null) {
-      _result.dart2jsVersion = dart2jsVersion;
+      result.dart2jsVersion = dart2jsVersion;
     }
     if (compilationMoment != null) {
-      _result.compilationMoment = compilationMoment;
+      result.compilationMoment = compilationMoment;
     }
     if (compilationDuration != null) {
-      _result.compilationDuration = compilationDuration;
+      result.compilationDuration = compilationDuration;
     }
     if (toProtoDuration != null) {
-      _result.toProtoDuration = toProtoDuration;
+      result.toProtoDuration = toProtoDuration;
     }
     if (dumpInfoDuration != null) {
-      _result.dumpInfoDuration = dumpInfoDuration;
+      result.dumpInfoDuration = dumpInfoDuration;
     }
     if (noSuchMethodEnabled != null) {
-      _result.noSuchMethodEnabled = noSuchMethodEnabled;
+      result.noSuchMethodEnabled = noSuchMethodEnabled;
     }
     if (isRuntimeTypeUsed != null) {
-      _result.isRuntimeTypeUsed = isRuntimeTypeUsed;
+      result.isRuntimeTypeUsed = isRuntimeTypeUsed;
     }
     if (isIsolateUsed != null) {
-      _result.isIsolateUsed = isIsolateUsed;
+      result.isIsolateUsed = isIsolateUsed;
     }
     if (isFunctionApplyUsed != null) {
-      _result.isFunctionApplyUsed = isFunctionApplyUsed;
+      result.isFunctionApplyUsed = isFunctionApplyUsed;
     }
     if (isMirrorsUsed != null) {
-      _result.isMirrorsUsed = isMirrorsUsed;
+      result.isMirrorsUsed = isMirrorsUsed;
     }
     if (minified != null) {
-      _result.minified = minified;
+      result.minified = minified;
     }
-    return _result;
+    return result;
   }
   factory ProgramInfoPB.fromBuffer($core.List<$core.int> i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
@@ -998,14 +998,14 @@
     $core.String? uri,
     $core.Iterable<$core.String>? childrenIds,
   }) {
-    final _result = create();
+    final result = create();
     if (uri != null) {
-      _result.uri = uri;
+      result.uri = uri;
     }
     if (childrenIds != null) {
-      _result.childrenIds.addAll(childrenIds);
+      result.childrenIds.addAll(childrenIds);
     }
-    return _result;
+    return result;
   }
   factory LibraryInfoPB.fromBuffer($core.List<$core.int> i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
@@ -1071,11 +1071,11 @@
   factory OutputUnitInfoPB({
     $core.Iterable<$core.String>? imports,
   }) {
-    final _result = create();
+    final result = create();
     if (imports != null) {
-      _result.imports.addAll(imports);
+      result.imports.addAll(imports);
     }
-    return _result;
+    return result;
   }
   factory OutputUnitInfoPB.fromBuffer($core.List<$core.int> i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
@@ -1135,14 +1135,14 @@
     $core.bool? isAbstract,
     $core.Iterable<$core.String>? childrenIds,
   }) {
-    final _result = create();
+    final result = create();
     if (isAbstract != null) {
-      _result.isAbstract = isAbstract;
+      result.isAbstract = isAbstract;
     }
     if (childrenIds != null) {
-      _result.childrenIds.addAll(childrenIds);
+      result.childrenIds.addAll(childrenIds);
     }
-    return _result;
+    return result;
   }
   factory ClassInfoPB.fromBuffer($core.List<$core.int> i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
@@ -1249,11 +1249,11 @@
   factory ConstantInfoPB({
     $core.String? code,
   }) {
-    final _result = create();
+    final result = create();
     if (code != null) {
-      _result.code = code;
+      result.code = code;
     }
-    return _result;
+    return result;
   }
   factory ConstantInfoPB.fromBuffer($core.List<$core.int> i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
@@ -1346,26 +1346,26 @@
     $core.bool? isConst,
     $core.String? initializerId,
   }) {
-    final _result = create();
+    final result = create();
     if (type != null) {
-      _result.type = type;
+      result.type = type;
     }
     if (inferredType != null) {
-      _result.inferredType = inferredType;
+      result.inferredType = inferredType;
     }
     if (childrenIds != null) {
-      _result.childrenIds.addAll(childrenIds);
+      result.childrenIds.addAll(childrenIds);
     }
     if (code != null) {
-      _result.code = code;
+      result.code = code;
     }
     if (isConst != null) {
-      _result.isConst = isConst;
+      result.isConst = isConst;
     }
     if (initializerId != null) {
-      _result.initializerId = initializerId;
+      result.initializerId = initializerId;
     }
-    return _result;
+    return result;
   }
   factory FieldInfoPB.fromBuffer($core.List<$core.int> i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
@@ -1478,11 +1478,11 @@
   factory TypedefInfoPB({
     $core.String? type,
   }) {
-    final _result = create();
+    final result = create();
     if (type != null) {
-      _result.type = type;
+      result.type = type;
     }
-    return _result;
+    return result;
   }
   factory TypedefInfoPB.fromBuffer($core.List<$core.int> i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
@@ -1563,20 +1563,20 @@
     $core.bool? isFactory,
     $core.bool? isExternal,
   }) {
-    final _result = create();
+    final result = create();
     if (isStatic != null) {
-      _result.isStatic = isStatic;
+      result.isStatic = isStatic;
     }
     if (isConst != null) {
-      _result.isConst = isConst;
+      result.isConst = isConst;
     }
     if (isFactory != null) {
-      _result.isFactory = isFactory;
+      result.isFactory = isFactory;
     }
     if (isExternal != null) {
-      _result.isExternal = isExternal;
+      result.isExternal = isExternal;
     }
-    return _result;
+    return result;
   }
   factory FunctionModifiersPB.fromBuffer($core.List<$core.int> i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
@@ -1687,17 +1687,17 @@
     $core.String? type,
     $core.String? declaredType,
   }) {
-    final _result = create();
+    final result = create();
     if (name != null) {
-      _result.name = name;
+      result.name = name;
     }
     if (type != null) {
-      _result.type = type;
+      result.type = type;
     }
     if (declaredType != null) {
-      _result.declaredType = declaredType;
+      result.declaredType = declaredType;
     }
-    return _result;
+    return result;
   }
   factory ParameterInfoPB.fromBuffer($core.List<$core.int> i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
@@ -1830,32 +1830,32 @@
     $core.int? inlinedCount,
     $core.String? code,
   }) {
-    final _result = create();
+    final result = create();
     if (functionModifiers != null) {
-      _result.functionModifiers = functionModifiers;
+      result.functionModifiers = functionModifiers;
     }
     if (childrenIds != null) {
-      _result.childrenIds.addAll(childrenIds);
+      result.childrenIds.addAll(childrenIds);
     }
     if (returnType != null) {
-      _result.returnType = returnType;
+      result.returnType = returnType;
     }
     if (inferredReturnType != null) {
-      _result.inferredReturnType = inferredReturnType;
+      result.inferredReturnType = inferredReturnType;
     }
     if (parameters != null) {
-      _result.parameters.addAll(parameters);
+      result.parameters.addAll(parameters);
     }
     if (sideEffects != null) {
-      _result.sideEffects = sideEffects;
+      result.sideEffects = sideEffects;
     }
     if (inlinedCount != null) {
-      _result.inlinedCount = inlinedCount;
+      result.inlinedCount = inlinedCount;
     }
     if (code != null) {
-      _result.code = code;
+      result.code = code;
     }
-    return _result;
+    return result;
   }
   factory FunctionInfoPB.fromBuffer($core.List<$core.int> i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
@@ -1986,11 +1986,11 @@
   factory ClosureInfoPB({
     $core.String? functionId,
   }) {
-    final _result = create();
+    final result = create();
     if (functionId != null) {
-      _result.functionId = functionId;
+      result.functionId = functionId;
     }
-    return _result;
+    return result;
   }
   factory ClosureInfoPB.fromBuffer($core.List<$core.int> i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
@@ -2059,14 +2059,14 @@
     $core.String? prefix,
     $core.Iterable<$core.String>? files,
   }) {
-    final _result = create();
+    final result = create();
     if (prefix != null) {
-      _result.prefix = prefix;
+      result.prefix = prefix;
     }
     if (files != null) {
-      _result.files.addAll(files);
+      result.files.addAll(files);
     }
-    return _result;
+    return result;
   }
   factory DeferredImportPB.fromBuffer($core.List<$core.int> i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
@@ -2146,17 +2146,17 @@
     $core.String? libraryName,
     $core.Iterable<DeferredImportPB>? imports,
   }) {
-    final _result = create();
+    final result = create();
     if (libraryUri != null) {
-      _result.libraryUri = libraryUri;
+      result.libraryUri = libraryUri;
     }
     if (libraryName != null) {
-      _result.libraryName = libraryName;
+      result.libraryName = libraryName;
     }
     if (imports != null) {
-      _result.imports.addAll(imports);
+      result.imports.addAll(imports);
     }
-    return _result;
+    return result;
   }
   factory LibraryDeferredImportsPB.fromBuffer($core.List<$core.int> i,
           [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) =>
diff --git a/pkg/dart2js_info/test/json_to_proto_test.dart b/pkg/dart2js_info/test/json_to_proto_test.dart
index 67f7ef0..dd79ac1 100644
--- a/pkg/dart2js_info/test/json_to_proto_test.dart
+++ b/pkg/dart2js_info/test/json_to_proto_test.dart
@@ -40,7 +40,7 @@
 
       final expectedPrefixes = <InfoKind, String>{};
       for (final kind in InfoKind.values) {
-        expectedPrefixes[kind] = kindToString(kind) + '/';
+        expectedPrefixes[kind] = '${kindToString(kind)}/';
       }
 
       for (final info in proto.allInfos.entries) {
diff --git a/pkg/dev_compiler/lib/src/compiler/js_metalet.dart b/pkg/dev_compiler/lib/src/compiler/js_metalet.dart
index 06d5941..379746d 100644
--- a/pkg/dev_compiler/lib/src/compiler/js_metalet.dart
+++ b/pkg/dev_compiler/lib/src/compiler/js_metalet.dart
@@ -322,7 +322,7 @@
   /// Compute fresh IDs to avoid
   static int _uniqueId = 0;
 
-  MetaLetVariable(this.displayName) : super(displayName + '@${++_uniqueId}');
+  MetaLetVariable(this.displayName) : super('$displayName@${++_uniqueId}');
 }
 
 class _VariableUseCounter extends BaseVisitor<void> {
diff --git a/pkg/dev_compiler/lib/src/compiler/js_names.dart b/pkg/dev_compiler/lib/src/compiler/js_names.dart
index 186a316..9e95de7 100644
--- a/pkg/dev_compiler/lib/src/compiler/js_names.dart
+++ b/pkg/dev_compiler/lib/src/compiler/js_names.dart
@@ -97,7 +97,7 @@
 /// `function` or `instanceof`, and their `name` field controls whether they
 /// refer to the same variable.
 class TemporaryNamer extends LocalNamer {
-  _FunctionScope scope;
+  _FunctionScope _scope;
 
   /// Listener to be notified when a name is selected (rename or not) for an
   /// `Identifier`.
@@ -106,23 +106,23 @@
   final NameListener _nameListener;
 
   TemporaryNamer(Node node, [this._nameListener])
-      : scope = _RenameVisitor.build(node).rootScope;
+      : _scope = _RenameVisitor.build(node).rootScope;
 
   @override
   String getName(Identifier node) {
-    var name = scope.renames[identifierKey(node)] ?? node.name;
+    var name = _scope.renames[identifierKey(node)] ?? node.name;
     _nameListener?.nameSelected(node, name);
     return name;
   }
 
   @override
   void enterScope(Node node) {
-    scope = scope.childScopes[node];
+    _scope = _scope.childScopes[node];
   }
 
   @override
   void leaveScope() {
-    scope = scope.parent;
+    _scope = _scope.parent;
   }
 }
 
diff --git a/pkg/dev_compiler/lib/src/compiler/module_builder.dart b/pkg/dev_compiler/lib/src/compiler/module_builder.dart
index 14685a4..9e89dc5 100644
--- a/pkg/dev_compiler/lib/src/compiler/module_builder.dart
+++ b/pkg/dev_compiler/lib/src/compiler/module_builder.dart
@@ -490,7 +490,7 @@
 
 /// Creates function name given [moduleName].
 String loadFunctionName(String moduleName) =>
-    'load__' + pathToJSIdentifier(moduleName.replaceAll('.', '_'));
+    'load__${pathToJSIdentifier(moduleName.replaceAll('.', '_'))}';
 
 /// Creates function name identifier given [moduleName].
 Identifier loadFunctionIdentifier(String moduleName) =>
diff --git a/pkg/dev_compiler/lib/src/compiler/module_containers.dart b/pkg/dev_compiler/lib/src/compiler/module_containers.dart
index a669e71..8e954be 100644
--- a/pkg/dev_compiler/lib/src/compiler/module_containers.dart
+++ b/pkg/dev_compiler/lib/src/compiler/module_containers.dart
@@ -9,7 +9,7 @@
 import '../js_ast/js_ast.dart' show js;
 
 /// Defines how to emit a value of a table
-typedef _EmitValue<K> = js_ast.Expression Function(K, ModuleItemData);
+typedef EmitValue<K> = js_ast.Expression Function(K, ModuleItemData);
 
 /// Represents a top-level property hoisted to a top-level object.
 class ModuleItemData {
@@ -125,7 +125,7 @@
   /// necessary.
   ///
   /// Uses [emitValue] to emit the values in the table.
-  List<js_ast.Statement> emit({_EmitValue<K> emitValue});
+  List<js_ast.Statement> emit({EmitValue<K> emitValue});
 }
 
 /// Associates a [K] with a container-unique JS key and arbitrary JS value.
@@ -184,7 +184,7 @@
   }
 
   @override
-  List<js_ast.Statement> emit({_EmitValue<K> emitValue}) {
+  List<js_ast.Statement> emit({EmitValue<K> emitValue}) {
     var containersToProperties = <js_ast.Identifier, List<js_ast.Property>>{};
     moduleItems.forEach((k, v) {
       if (!incrementalMode && _noEmit.contains(k)) return;
@@ -240,7 +240,7 @@
   }
 
   @override
-  List<js_ast.Statement> emit({_EmitValue<K> emitValue}) {
+  List<js_ast.Statement> emit({EmitValue<K> emitValue}) {
     var properties = List<js_ast.Expression>.filled(length, null);
 
     // If the entire array holds just one value, generate a short initializer.
diff --git a/pkg/dev_compiler/lib/src/js_ast/printer.dart b/pkg/dev_compiler/lib/src/js_ast/printer.dart
index ff54cdb..5d81fe5 100644
--- a/pkg/dev_compiler/lib/src/js_ast/printer.dart
+++ b/pkg/dev_compiler/lib/src/js_ast/printer.dart
@@ -4,7 +4,7 @@
 
 // @dart = 2.9
 
-// ignore_for_file: always_declare_return_types, prefer_single_quotes
+// ignore_for_file: always_declare_return_types, prefer_single_quotes, prefer_interpolation_to_compose_strings
 // ignore_for_file: prefer_collection_literals, omit_local_variable_types
 // ignore_for_file: prefer_final_fields
 // ignore_for_file: prefer_initializing_formals
diff --git a/pkg/dev_compiler/lib/src/kernel/command.dart b/pkg/dev_compiler/lib/src/kernel/command.dart
index 6f81197..bc13226 100644
--- a/pkg/dev_compiler/lib/src/kernel/command.dart
+++ b/pkg/dev_compiler/lib/src/kernel/command.dart
@@ -177,7 +177,7 @@
 
   Uri toCustomUri(Uri uri) {
     if (!uri.hasScheme) {
-      return Uri(scheme: options.multiRootScheme, path: '/' + uri.path);
+      return Uri(scheme: options.multiRootScheme, path: '/${uri.path}');
     }
     return uri;
   }
@@ -381,7 +381,7 @@
     if (identical(compilerState, oldCompilerState)) {
       component.unbindCanonicalNames();
     }
-    var sink = File(p.withoutExtension(outPaths.first) + '.dill').openWrite();
+    var sink = File('${p.withoutExtension(outPaths.first)}.dill').openWrite();
     // TODO(jmesserly): this appears to save external libraries.
     // Do we need to run them through an outlining step so they can be saved?
     kernel.BinaryPrinter(sink).writeComponentFile(component);
@@ -404,7 +404,7 @@
     if (identical(compilerState, oldCompilerState)) {
       compiledLibraries.unbindCanonicalNames();
     }
-    fullDillUri = p.withoutExtension(outPaths.first) + '.full.dill';
+    fullDillUri = '${p.withoutExtension(outPaths.first)}.full.dill';
     var sink = File(fullDillUri).openWrite();
     kernel.BinaryPrinter(sink).writeComponentFile(compiledLibraries);
     outFiles.add(sink.flush().then((_) => sink.close()));
@@ -418,8 +418,8 @@
     }
     var sb = StringBuffer();
     kernel.Printer(sb).writeComponentFile(component);
-    outFiles.add(File(outPaths.first + '.txt').writeAsString(sb.toString()));
-    outFiles.add(File(outPaths.first.split('.')[0] + '.ast.xml')
+    outFiles.add(File('${outPaths.first}.txt').writeAsString(sb.toString()));
+    outFiles.add(File('${outPaths.first.split('.')[0]}.ast.xml')
         .writeAsString(DebugPrinter.prettyPrint(compiledLibraries)));
   }
 
@@ -583,7 +583,7 @@
         buildSourceMap: options.sourceMap,
         inlineSourceMap: options.inlineSourceMap,
         jsUrl: p.toUri(output).toString(),
-        mapUrl: p.toUri(output + '.map').toString(),
+        mapUrl: p.toUri('$output.map').toString(),
         customScheme: options.multiRootScheme,
         multiRootOutputPath: options.multiRootOutputPath,
         component: component);
@@ -591,7 +591,7 @@
     outFiles.add(file.writeAsString(jsCode.code));
     if (jsCode.sourceMap != null) {
       outFiles.add(
-          File(output + '.map').writeAsString(json.encode(jsCode.sourceMap)));
+          File('$output.map').writeAsString(json.encode(jsCode.sourceMap)));
     }
   }
   await Future.wait(outFiles);
diff --git a/pkg/dev_compiler/lib/src/kernel/compiler.dart b/pkg/dev_compiler/lib/src/kernel/compiler.dart
index f0a8fc7..29d4048 100644
--- a/pkg/dev_compiler/lib/src/kernel/compiler.dart
+++ b/pkg/dev_compiler/lib/src/kernel/compiler.dart
@@ -1134,8 +1134,8 @@
       var mixinType =
           _hierarchy.getClassAsInstanceOf(c, mixinClass).asInterfaceType;
       var mixinName =
-          getLocalClassName(superclass) + '_' + getLocalClassName(mixinClass);
-      var mixinId = _emitTemporaryId(mixinName + '\$');
+          '${getLocalClassName(superclass)}_${getLocalClassName(mixinClass)}';
+      var mixinId = _emitTemporaryId('$mixinName\$');
       // Collect all forwarding stub setters from anonymous mixins classes.
       // These will contain covariant parameter checks that need to be applied.
       var savedClassProperties = _classProperties;
@@ -1246,7 +1246,7 @@
           case 'Future':
           case 'Stream':
           case 'StreamSubscription':
-            return runtimeCall('is' + interface.name);
+            return runtimeCall('is${interface.name}');
         }
       }
       return null;
@@ -2635,7 +2635,7 @@
 
   js_ast.PropertyAccess _emitFutureOrNameNoInterop({String suffix = ''}) {
     return js_ast.PropertyAccess(emitLibraryName(_coreTypes.asyncLibrary),
-        propertyName('FutureOr' + suffix));
+        propertyName('FutureOr$suffix'));
   }
 
   /// Emits the member name portion of a top-level member.
@@ -6450,11 +6450,11 @@
     // Emit the constant as an integer, if possible.
     if (value.isFinite) {
       var intValue = value.toInt();
-      const _MIN_INT32 = -0x80000000;
-      const _MAX_INT32 = 0x7FFFFFFF;
+      const minInt32 = -0x80000000;
+      const maxInt32 = 0x7FFFFFFF;
       if (intValue.toDouble() == value &&
-          intValue >= _MIN_INT32 &&
-          intValue <= _MAX_INT32) {
+          intValue >= minInt32 &&
+          intValue <= maxInt32) {
         return js.number(intValue);
       }
     }
@@ -6474,7 +6474,7 @@
   js_ast.Expression visitStringConstant(StringConstant node) =>
       js.escapedString(node.value, '"');
 
-  // DDC does not currently use the non-primivite constant nodes; rather these
+  // DDC does not currently use the non-primitive constant nodes; rather these
   // are emitted via their normal expression nodes.
   @override
   js_ast.Expression defaultConstant(Constant node) => _emitInvalidNode(node);
diff --git a/pkg/dev_compiler/test/modular_suite.dart b/pkg/dev_compiler/test/modular_suite.dart
index 77ee34f..0df7a21 100644
--- a/pkg/dev_compiler/test/modular_suite.dart
+++ b/pkg/dev_compiler/test/modular_suite.dart
@@ -266,7 +266,7 @@
     ''';
 
     var wrapper =
-        root.resolveUri(toUri(module, jsId)).toFilePath() + '.wrapper.js';
+        '${root.resolveUri(toUri(module, jsId)).toFilePath()}.wrapper.js';
     await File(wrapper).writeAsString(runjs);
     var d8Args = ['--module', wrapper];
     var result = await _runProcess(
diff --git a/pkg/dev_compiler/test/modular_suite_nnbd.dart b/pkg/dev_compiler/test/modular_suite_nnbd.dart
index 2cba274..4c7c3b0 100644
--- a/pkg/dev_compiler/test/modular_suite_nnbd.dart
+++ b/pkg/dev_compiler/test/modular_suite_nnbd.dart
@@ -270,7 +270,7 @@
     ''';
 
     var wrapper =
-        root.resolveUri(toUri(module, jsId)).toFilePath() + '.wrapper.js';
+        '${root.resolveUri(toUri(module, jsId)).toFilePath()}.wrapper.js';
     await File(wrapper).writeAsString(runjs);
     var d8Args = ['--module', wrapper];
     var result = await _runProcess(
diff --git a/pkg/dev_compiler/web/source_map_stack_trace.dart b/pkg/dev_compiler/web/source_map_stack_trace.dart
index aa9eaa6..cb74f58 100644
--- a/pkg/dev_compiler/web/source_map_stack_trace.dart
+++ b/pkg/dev_compiler/web/source_map_stack_trace.dart
@@ -52,7 +52,7 @@
         }
         var packageRoot = '$root/packages';
         if (p.url.isWithin(packageRoot, sourceUrl)) {
-          sourceUrl = 'package:' + p.url.relative(sourceUrl, from: packageRoot);
+          sourceUrl = 'package:${p.url.relative(sourceUrl, from: packageRoot)}';
           break;
         }
       }