Fix unnecessary_new in analyzer.

R=brianwilkerson@google.com

Change-Id: I70f80baa3da4b14c0a52c1f28da16a9ad26d7dda
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/127424
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

Author: scheglov

pkg/analyzer/analysis_options.yaml

@@ -21,10 +21,6 @@ analyzer:
     # is mechanical, via `dartfmt --fix-optional-const`, but not worth the
     # churn today.
     unnecessary_const: ignore
-    # TODO(srawlins): At the time of writing, 3200 violations in lib/. The fix
-    # is mechanical, via `dartfmt --fix-optional-new`, but not worth the churn
-    # today.
-    unnecessary_new: ignore
 
 linter:
   rules:

pkg/analyzer/lib/analyzer.dart

@@ -54,7 +54,7 @@ CompilationUnit parseCompilationUnit(String contents,
     FeatureSet featureSet}) {
   // TODO(paulberry): make featureSet a required parameter
   featureSet ??= FeatureSet.fromEnableFlags([]);
-  Source source = new StringSource(contents, name);
+  Source source = StringSource(contents, name);
   return _parseSource(contents, source, featureSet,
       suppressErrors: suppressErrors, parseFunctionBodies: parseFunctionBodies);
 }
@@ -79,17 +79,17 @@ CompilationUnit parseDartFile(String path,
     FeatureSet featureSet}) {
   // TODO(paulberry): Make featureSet a required parameter
   featureSet ??= FeatureSet.fromEnableFlags([]);
-  String contents = new File(path).readAsStringSync();
-  var sourceFactory = new SourceFactory(
-      [new ResourceUriResolver(PhysicalResourceProvider.INSTANCE)]);
+  String contents = File(path).readAsStringSync();
+  var sourceFactory =
+      SourceFactory([ResourceUriResolver(PhysicalResourceProvider.INSTANCE)]);
 
   var absolutePath = pathos.absolute(path);
   var source = sourceFactory.forUri(pathos.toUri(absolutePath).toString());
   if (source == null) {
-    throw new ArgumentError("Can't get source for path $path");
+    throw ArgumentError("Can't get source for path $path");
   }
   if (!source.exists()) {
-    throw new ArgumentError("Source $source doesn't exist");
+    throw ArgumentError("Source $source doesn't exist");
   }
 
   return _parseSource(contents, source, featureSet,
@@ -118,15 +118,15 @@ CompilationUnit parseDirectives(String contents,
     {String name, bool suppressErrors = false, FeatureSet featureSet}) {
   // TODO(paulberry): make featureSet a required parameter.
   featureSet ??= FeatureSet.fromEnableFlags([]);
-  var source = new StringSource(contents, name);
-  var errorCollector = new _ErrorCollector();
-  var reader = new CharSequenceReader(contents);
-  var scanner = new Scanner(source, reader, errorCollector)
+  var source = StringSource(contents, name);
+  var errorCollector = _ErrorCollector();
+  var reader = CharSequenceReader(contents);
+  var scanner = Scanner(source, reader, errorCollector)
     ..configureFeatures(featureSet);
   var token = scanner.tokenize();
-  var parser = new Parser(source, errorCollector, featureSet: featureSet);
+  var parser = Parser(source, errorCollector, featureSet: featureSet);
   var unit = parser.parseDirectives(token);
-  unit.lineInfo = new LineInfo(scanner.lineStarts);
+  unit.lineInfo = LineInfo(scanner.lineStarts);
 
   if (errorCollector.hasErrors && !suppressErrors) throw errorCollector.group;
 
@@ -142,15 +142,15 @@ String stringLiteralToString(StringLiteral literal) {
 CompilationUnit _parseSource(
     String contents, Source source, FeatureSet featureSet,
     {bool suppressErrors = false, bool parseFunctionBodies = true}) {
-  var reader = new CharSequenceReader(contents);
-  var errorCollector = new _ErrorCollector();
-  var scanner = new Scanner(source, reader, errorCollector)
+  var reader = CharSequenceReader(contents);
+  var errorCollector = _ErrorCollector();
+  var scanner = Scanner(source, reader, errorCollector)
     ..configureFeatures(featureSet);
   var token = scanner.tokenize();
-  var parser = new Parser(source, errorCollector, featureSet: featureSet)
+  var parser = Parser(source, errorCollector, featureSet: featureSet)
     ..parseFunctionBodies = parseFunctionBodies;
   var unit = parser.parseCompilationUnit(token)
-    ..lineInfo = new LineInfo(scanner.lineStarts);
+    ..lineInfo = LineInfo(scanner.lineStarts);
 
   if (errorCollector.hasErrors && !suppressErrors) throw errorCollector.group;
 
@@ -165,7 +165,7 @@ class _ErrorCollector extends AnalysisErrorListener {
 
   /// The group of errors collected.
   AnalyzerErrorGroup get group =>
-      new AnalyzerErrorGroup.fromAnalysisErrors(_errors);
+      AnalyzerErrorGroup.fromAnalysisErrors(_errors);
 
   /// Whether any errors where collected.
   bool get hasErrors => _errors.isNotEmpty;

pkg/analyzer/lib/dart/analysis/declared_variables.dart

@@ -52,14 +52,14 @@ class DeclaredVariables {
   DartObject getBool(TypeProvider typeProvider, String name) {
     String value = _declaredVariables[name];
     if (value == null) {
-      return new DartObjectImpl(typeProvider.boolType, BoolState.UNKNOWN_VALUE);
+      return DartObjectImpl(typeProvider.boolType, BoolState.UNKNOWN_VALUE);
     }
     if (value == "true") {
-      return new DartObjectImpl(typeProvider.boolType, BoolState.TRUE_STATE);
+      return DartObjectImpl(typeProvider.boolType, BoolState.TRUE_STATE);
     } else if (value == "false") {
-      return new DartObjectImpl(typeProvider.boolType, BoolState.FALSE_STATE);
+      return DartObjectImpl(typeProvider.boolType, BoolState.FALSE_STATE);
     }
-    return new DartObjectImpl(typeProvider.nullType, NullState.NULL_STATE);
+    return DartObjectImpl(typeProvider.nullType, NullState.NULL_STATE);
   }
 
   /// Return the value of the variable with the given [name] interpreted as an
@@ -69,15 +69,15 @@ class DeclaredVariables {
   DartObject getInt(TypeProvider typeProvider, String name) {
     String value = _declaredVariables[name];
     if (value == null) {
-      return new DartObjectImpl(typeProvider.intType, IntState.UNKNOWN_VALUE);
+      return DartObjectImpl(typeProvider.intType, IntState.UNKNOWN_VALUE);
     }
     int bigInteger;
     try {
       bigInteger = int.parse(value);
     } on FormatException {
-      return new DartObjectImpl(typeProvider.nullType, NullState.NULL_STATE);
+      return DartObjectImpl(typeProvider.nullType, NullState.NULL_STATE);
     }
-    return new DartObjectImpl(typeProvider.intType, new IntState(bigInteger));
+    return DartObjectImpl(typeProvider.intType, IntState(bigInteger));
   }
 
   /// Return the value of the variable with the given [name] interpreted as a
@@ -89,9 +89,8 @@ class DeclaredVariables {
   DartObject getString(TypeProvider typeProvider, String name) {
     String value = _declaredVariables[name];
     if (value == null) {
-      return new DartObjectImpl(
-          typeProvider.stringType, StringState.UNKNOWN_VALUE);
+      return DartObjectImpl(typeProvider.stringType, StringState.UNKNOWN_VALUE);
     }
-    return new DartObjectImpl(typeProvider.stringType, new StringState(value));
+    return DartObjectImpl(typeProvider.stringType, StringState(value));
   }
 }

pkg/analyzer/lib/dart/analysis/utilities.dart

@@ -124,7 +124,7 @@ ParseStringResult parseString(
   ParseStringResult result =
       ParseStringResultImpl(content, unit, errorCollector.errors);
   if (throwIfDiagnostics && result.errors.isNotEmpty) {
-    throw new ArgumentError('Content produced diagnostics when parsed');
+    throw ArgumentError('Content produced diagnostics when parsed');
   }
   return result;
 }
@@ -149,13 +149,13 @@ Future<ResolvedUnitResult> resolveFile(
 /// If a [resourceProvider] is given, it will be used to access the file system.
 AnalysisContext _createAnalysisContext(
     {@required String path, ResourceProvider resourceProvider}) {
-  AnalysisContextCollection collection = new AnalysisContextCollection(
+  AnalysisContextCollection collection = AnalysisContextCollection(
     includedPaths: <String>[path],
     resourceProvider: resourceProvider ?? PhysicalResourceProvider.INSTANCE,
   );
   List<AnalysisContext> contexts = collection.contexts;
   if (contexts.length != 1) {
-    throw new ArgumentError('path must be an absolute path to a single file');
+    throw ArgumentError('path must be an absolute path to a single file');
   }
   return contexts[0];
 }

pkg/analyzer/lib/dart/ast/ast.dart

@@ -3069,8 +3069,8 @@ abstract class ImportDirective implements NamespaceDirective {
     // hides and shows
     //
     NodeList<Combinator> combinators1 = import1.combinators;
-    List<String> allHides1 = new List<String>();
-    List<String> allShows1 = new List<String>();
+    List<String> allHides1 = List<String>();
+    List<String> allShows1 = List<String>();
     int length1 = combinators1.length;
     for (int i = 0; i < length1; i++) {
       Combinator combinator = combinators1[i];
@@ -3092,8 +3092,8 @@ abstract class ImportDirective implements NamespaceDirective {
       }
     }
     NodeList<Combinator> combinators2 = import2.combinators;
-    List<String> allHides2 = new List<String>();
-    List<String> allShows2 = new List<String>();
+    List<String> allHides2 = List<String>();
+    List<String> allShows2 = List<String>();
     int length2 = combinators2.length;
     for (int i = 0; i < length2; i++) {
       Combinator combinator = combinators2[i];

pkg/analyzer/lib/dart/ast/standard_ast_factory.dart

@@ -6,4 +6,4 @@ import 'package:analyzer/dart/ast/ast_factory.dart';
 import 'package:analyzer/src/dart/ast/ast_factory.dart';
 
 /// Gets an instance of [AstFactory] based on the standard AST implementation.
-final AstFactory astFactory = new AstFactoryImpl();
+final AstFactory astFactory = AstFactoryImpl();

pkg/analyzer/lib/dart/ast/visitor.dart

@@ -49,15 +49,15 @@ import 'package:analyzer/dart/ast/ast.dart';
 class BreadthFirstVisitor<R> extends GeneralizingAstVisitor<R> {
   /// A queue holding the nodes that have not yet been visited in the order in
   /// which they ought to be visited.
-  Queue<AstNode> _queue = new Queue<AstNode>();
+  Queue<AstNode> _queue = Queue<AstNode>();
 
   /// A visitor, used to visit the children of the current node, that will add
   /// the nodes it visits to the [_queue].
   _BreadthFirstChildVisitor _childVisitor;
 
   /// Initialize a newly created visitor.
   BreadthFirstVisitor() {
-    _childVisitor = new _BreadthFirstChildVisitor(this);
+    _childVisitor = _BreadthFirstChildVisitor(this);
   }
 
   /// Visit all nodes in the tree starting at the given [root] node, in
@@ -2096,7 +2096,7 @@ class ThrowingAstVisitor<R> implements AstVisitor<R> {
   R visitYieldStatement(YieldStatement node) => _throw(node);
 
   R _throw(AstNode node) {
-    throw new Exception('Missing implementation of visit${node.runtimeType}');
+    throw Exception('Missing implementation of visit${node.runtimeType}');
   }
 }
 
@@ -2113,7 +2113,7 @@ class TimedAstVisitor<T> implements AstVisitor<T> {
   /// Initialize a newly created visitor to time calls to the given base
   /// visitor's visits.
   TimedAstVisitor(this._baseVisitor, [Stopwatch watch])
-      : stopwatch = watch ?? new Stopwatch();
+      : stopwatch = watch ?? Stopwatch();
 
   @override
   T visitAdjacentStrings(AdjacentStrings node) {

pkg/analyzer/lib/dart/element/visitor.dart

@@ -469,7 +469,6 @@ class ThrowingElementVisitor<R> implements ElementVisitor<R> {
   R visitTypeParameterElement(TypeParameterElement element) => _throw(element);
 
   R _throw(Element element) {
-    throw new Exception(
-        'Missing implementation of visit${element.runtimeType}');
+    throw Exception('Missing implementation of visit${element.runtimeType}');
   }
 }

pkg/analyzer/lib/error/error.dart

@@ -844,7 +844,7 @@ HashMap<String, ErrorCode> _uniqueNameToCodeMap;
  */
 ErrorCode errorCodeByUniqueName(String uniqueName) {
   if (_uniqueNameToCodeMap == null) {
-    _uniqueNameToCodeMap = new HashMap<String, ErrorCode>();
+    _uniqueNameToCodeMap = HashMap<String, ErrorCode>();
     for (ErrorCode errorCode in errorCodeValues) {
       _uniqueNameToCodeMap[errorCode.uniqueName] = errorCode;
     }
@@ -932,7 +932,7 @@ class AnalysisError implements Diagnostic {
     if (correctionTemplate != null) {
       this._correction = formatList(correctionTemplate, arguments);
     }
-    _problemMessage = new DiagnosticMessageImpl(
+    _problemMessage = DiagnosticMessageImpl(
         filePath: source?.fullName,
         length: length,
         message: message,
@@ -946,7 +946,7 @@ class AnalysisError implements Diagnostic {
   AnalysisError.forValues(this.source, int offset, int length, this.errorCode,
       String message, this._correction,
       {List<DiagnosticMessage> contextMessages = const []}) {
-    _problemMessage = new DiagnosticMessageImpl(
+    _problemMessage = DiagnosticMessageImpl(
         filePath: source?.fullName,
         length: length,
         message: message,
@@ -1005,8 +1005,7 @@ class AnalysisError implements Diagnostic {
       case ErrorSeverity.INFO:
         return Severity.info;
       default:
-        throw new StateError(
-            'Invalid error severity: ${errorCode.errorSeverity}');
+        throw StateError('Invalid error severity: ${errorCode.errorSeverity}');
     }
   }
 
@@ -1039,7 +1038,7 @@ class AnalysisError implements Diagnostic {
 
   @override
   String toString() {
-    StringBuffer buffer = new StringBuffer();
+    StringBuffer buffer = StringBuffer();
     buffer.write((source != null) ? source.fullName : "<unknown source>");
     buffer.write("(");
     buffer.write(offset);
@@ -1056,7 +1055,7 @@ class AnalysisError implements Diagnostic {
    * a single list of errors.
    */
   static List<AnalysisError> mergeLists(List<List<AnalysisError>> errorLists) {
-    Set<AnalysisError> errors = new HashSet<AnalysisError>();
+    Set<AnalysisError> errors = HashSet<AnalysisError>();
     for (List<AnalysisError> errorList in errorLists) {
       errors.addAll(errorList);
     }

pkg/analyzer/lib/error/listener.dart

@@ -22,7 +22,7 @@ abstract class AnalysisErrorListener {
   /**
    * An error listener that ignores errors that are reported to it.
    */
-  static final AnalysisErrorListener NULL_LISTENER = new _NullErrorListener();
+  static final AnalysisErrorListener NULL_LISTENER = _NullErrorListener();
 
   /**
    * This method is invoked when an [error] has been found by the analysis
@@ -79,9 +79,9 @@ class ErrorReporter {
    */
   ErrorReporter(this._errorListener, this._defaultSource) {
     if (_errorListener == null) {
-      throw new ArgumentError("An error listener must be provided");
+      throw ArgumentError("An error listener must be provided");
     } else if (_defaultSource == null) {
-      throw new ArgumentError("A default source must be provided");
+      throw ArgumentError("A default source must be provided");
     }
     this._source = _defaultSource;
   }
@@ -139,8 +139,8 @@ class ErrorReporter {
    */
   void reportErrorForOffset(ErrorCode errorCode, int offset, int length,
       [List<Object> arguments]) {
-    _errorListener.onError(
-        new AnalysisError(_source, offset, length, errorCode, arguments));
+    _errorListener
+        .onError(AnalysisError(_source, offset, length, errorCode, arguments));
   }
 
   /**
@@ -167,7 +167,7 @@ class ErrorReporter {
    */
   void reportErrorMessage(
       ErrorCode errorCode, int offset, int length, Message message) {
-    _errorListener.onError(new AnalysisError.forValues(
+    _errorListener.onError(AnalysisError.forValues(
         _source, offset, length, errorCode, message.message, message.tip));
   }
 
@@ -200,7 +200,7 @@ class ErrorReporter {
       if (type is FunctionType) {
         String name = type.name;
         if (name != null && name.isNotEmpty) {
-          StringBuffer buffer = new StringBuffer();
+          StringBuffer buffer = StringBuffer();
           buffer.write(name);
           (type as TypeImpl).appendTo(buffer, withNullability: false);
           return buffer.toString();
@@ -216,7 +216,7 @@ class ErrorReporter {
         String displayName = computeDisplayName(argument);
         List<_TypeToConvert> types =
             typeGroups.putIfAbsent(displayName, () => <_TypeToConvert>[]);
-        types.add(new _TypeToConvert(i, argument, displayName));
+        types.add(_TypeToConvert(i, argument, displayName));
       }
     }
     for (List<_TypeToConvert> typeGroup in typeGroups.values) {
@@ -230,7 +230,7 @@ class ErrorReporter {
         for (_TypeToConvert typeToConvert in typeGroup) {
           for (Element element in typeToConvert.allElements()) {
             Set<Element> elements = nameToElementMap.putIfAbsent(
-                element.name, () => new Set<Element>());
+                element.name, () => Set<Element>());
             elements.add(element);
           }
         }
@@ -243,7 +243,7 @@ class ErrorReporter {
             String name = element.name;
             if (nameToElementMap[name].length > 1) {
               if (buffer == null) {
-                buffer = new StringBuffer();
+                buffer = StringBuffer();
                 buffer.write('where ');
               } else {
                 buffer.write(', ');
@@ -293,7 +293,7 @@ class RecordingErrorListener implements AnalysisErrorListener {
 
   @override
   void onError(AnalysisError error) {
-    _errors ??= new HashSet<AnalysisError>();
+    _errors ??= HashSet<AnalysisError>();
     _errors.add(error);
   }
 }
@@ -323,7 +323,7 @@ class _TypeToConvert {
 
   List<Element> allElements() {
     if (_allElements == null) {
-      Set<Element> elements = new Set<Element>();
+      Set<Element> elements = Set<Element>();
 
       void addElementsFrom(DartType type) {
         if (type is FunctionType) {