Check for unnecessary_parenthesis in analyzer.

R=brianwilkerson@google.com

Change-Id: I2e8af156a190b51741d60fdb0217101c15306a79
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/153622
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

pkg/analyzer/analysis_options.yaml

@@ -19,3 +19,4 @@ linter:
     - avoid_unused_constructor_parameters
     - empty_statements
     - unnecessary_brace_in_string_interps
+    - unnecessary_parenthesis

pkg/analyzer/lib/file_system/memory_file_system.dart

@@ -28,12 +28,12 @@ class MemoryResourceProvider implements ResourceProvider {
 
   MemoryResourceProvider(
       {pathos.Context context, @deprecated bool isWindows = false})
-      : _pathContext = (context ??= pathos.style == pathos.Style.windows
+      : _pathContext = context ??= pathos.style == pathos.Style.windows
             // On Windows, ensure that the current drive matches
             // the drive inserted by MemoryResourceProvider.convertPath
             // so that packages are mapped to the correct drive
             ? pathos.Context(current: 'C:\\')
-            : pathos.context);
+            : pathos.context;
 
   @override
   pathos.Context get pathContext => _pathContext;

pkg/analyzer/lib/src/dart/analysis/fletcher16.dart

@@ -25,5 +25,5 @@ int fletcher16(List<int> data) {
   c0 = c0 % 255;
   c1 = c1 % 255;
 
-  return (c1 << 8 | c0);
+  return c1 << 8 | c0;
 }

pkg/analyzer/lib/src/dart/constant/evaluation.dart

@@ -355,7 +355,7 @@ class ConstantEvaluationEngine {
         if (defaultSuperInvocationNeeded) {
           // No explicit superconstructor invocation found, so we need to
           // manually insert a reference to the implicit superconstructor.
-          InterfaceType superclass = (constant.returnType).superclass;
+          InterfaceType superclass = constant.returnType.superclass;
           if (superclass != null && !superclass.isDartCoreObject) {
             ConstructorElement unnamedConstructor =
                 superclass.element.unnamedConstructor?.declaration;

pkg/analyzer/lib/src/dart/constant/value.dart

@@ -1157,7 +1157,7 @@ class DoubleState extends NumState {
     if (value == null) {
       return UNKNOWN_VALUE;
     }
-    return DoubleState(-(value));
+    return DoubleState(-value);
   }
 
   @override

pkg/analyzer/lib/src/dart/element/generic_inferrer.dart

@@ -496,7 +496,7 @@ class GenericInferrer {
       var prefix = parts[0];
       var middle = parts[1];
       var prefixPad = ' ' * (prefixMax - prefix.length);
-      var middlePad = ' ' * (prefixMax);
+      var middlePad = ' ' * prefixMax;
       var end = "";
       if (parts.length > 2) {
         end = '\n  $middlePad ${parts[2]}';

pkg/analyzer/lib/src/dart/element/type_provider.dart

@@ -27,7 +27,7 @@ abstract class TypeProviderBase implements TypeProvider {
   @override
   bool isObjectGetter(String id) {
     PropertyAccessorElement element = objectType.element.getGetter(id);
-    return (element != null && !element.isStatic);
+    return element != null && !element.isStatic;
   }
 
   @override
@@ -38,7 +38,7 @@ abstract class TypeProviderBase implements TypeProvider {
   @override
   bool isObjectMethod(String id) {
     MethodElement element = objectType.element.getMethod(id);
-    return (element != null && !element.isStatic);
+    return element != null && !element.isStatic;
   }
 }
 

pkg/analyzer/lib/src/dart/micro/resolve_file.dart

@@ -185,7 +185,7 @@ class FileResolver {
 
           bytes = CiderUnitErrorsBuilder(
             signature: errorsSignature,
-            errors: errors.map((ErrorEncoding.encode)).toList(),
+            errors: errors.map(ErrorEncoding.encode).toList(),
           ).toBuffer();
           byteStore.put(errorsKey, errorsSignature, bytes);
         }

pkg/analyzer/lib/src/error/correct_override.dart

@@ -172,7 +172,7 @@ class CovariantParametersVerifier {
             i,
           );
           if (superParameter != null) {
-            var parameterSuperList = (result[parameter] ??= []);
+            var parameterSuperList = result[parameter] ??= [];
             var superType = _superSubstitution(superMember)
                 .substituteType(superParameter.type);
             parameterSuperList.add(

pkg/analyzer/test/generated/parser_fasta_test.dart

@@ -1676,7 +1676,7 @@ class ExtensionMethodsParserTest_Fasta extends FastaParserTestCase {
     var extension = unit.declarations[0] as ExtensionDeclaration;
     expect(extension.name.name, 'E');
     expect(extension.onKeyword.lexeme, 'on');
-    var namedType = (extension.extendedType as NamedType);
+    var namedType = extension.extendedType as NamedType;
     expect(namedType.name.name, 'C');
     expect(namedType.typeArguments.arguments, hasLength(1));
     expect(extension.members, hasLength(0));
@@ -1688,7 +1688,7 @@ class ExtensionMethodsParserTest_Fasta extends FastaParserTestCase {
     var extension = unit.declarations[0] as ExtensionDeclaration;
     expect(extension.name.name, 'E');
     expect(extension.onKeyword.lexeme, 'on');
-    var namedType = (extension.extendedType as NamedType);
+    var namedType = extension.extendedType as NamedType;
     expect(namedType.name.name, 'C');
     expect(namedType.typeArguments.arguments, hasLength(1));
     expect(extension.members, hasLength(0));
@@ -1700,7 +1700,7 @@ class ExtensionMethodsParserTest_Fasta extends FastaParserTestCase {
     var extension = unit.declarations[0] as ExtensionDeclaration;
     expect(extension.name, isNull);
     expect(extension.onKeyword.lexeme, 'on');
-    var namedType = (extension.extendedType as NamedType);
+    var namedType = extension.extendedType as NamedType;
     expect(namedType.name.name, 'C');
     expect(namedType.typeArguments.arguments, hasLength(1));
     expect(extension.members, hasLength(0));
@@ -1799,7 +1799,7 @@ class C {}
     expect(extension.name.name, 'E');
     expect(extension.onKeyword.lexeme, 'on');
     expect((extension.extendedType as NamedType).name.name, 'C');
-    var namedType = (extension.extendedType as NamedType);
+    var namedType = extension.extendedType as NamedType;
     expect(namedType.name.name, 'C');
     expect(namedType.typeArguments, isNull);
     expect(extension.members, hasLength(0));
@@ -1836,7 +1836,7 @@ class C {}
     expect(extension.name, isNull);
     expect(extension.onKeyword.lexeme, 'on');
     expect((extension.extendedType as NamedType).name.name, 'C');
-    var namedType = (extension.extendedType as NamedType);
+    var namedType = extension.extendedType as NamedType;
     expect(namedType.name.name, 'C');
     expect(namedType.typeArguments, isNull);
     expect(extension.members, hasLength(0));

pkg/analyzer/test/generated/parser_test.dart

@@ -4416,8 +4416,8 @@ class Wrong<T> {
     ]);
     FunctionDeclaration declaration = unit.declarations.first;
     BlockFunctionBody blockBody = declaration.functionExpression.body;
-    ExpressionStatement statement = (blockBody).block.statements.first;
-    Expression expression = (statement).expression;
+    ExpressionStatement statement = blockBody.block.statements.first;
+    Expression expression = statement.expression;
     expect(expression, isSuperExpression);
     SuperExpression superExpression = expression;
     expect(superExpression.superKeyword, isNotNull);
@@ -11450,7 +11450,7 @@ class C {
 
   void test_missing_commaInArgumentList() {
     MethodInvocation expression = parseExpression("f(x: 1 y: 2)",
-        errors: ([expectedError(ParserErrorCode.EXPECTED_TOKEN, 7, 1)]));
+        errors: [expectedError(ParserErrorCode.EXPECTED_TOKEN, 7, 1)]);
     NodeList<Expression> arguments = expression.argumentList.arguments;
     expect(arguments, hasLength(2));
   }

pkg/analyzer/test/generated/strong_mode_test.dart

@@ -1263,9 +1263,9 @@ void _mergeSort<T>(T Function(T) list, int compare(T a, T b), T Function(T) targ
     assertNoErrors(source);
     verify([source]);
     var unit = analysisResult.unit;
-    var body = (AstFinder.getTopLevelFunction(unit, '_mergeSort')
+    var body = AstFinder.getTopLevelFunction(unit, '_mergeSort')
         .functionExpression
-        .body as BlockFunctionBody);
+        .body as BlockFunctionBody;
     var stmts = body.block.statements;
     for (ExpressionStatement stmt in stmts) {
       MethodInvocation invoke = stmt.expression;
@@ -1290,9 +1290,9 @@ void _mergeSort<T>(List<T> list, int compare(T a, T b), List<T> target) {
     assertNoErrors(source);
     verify([source]);
     var unit = analysisResult.unit;
-    var body = (AstFinder.getTopLevelFunction(unit, '_mergeSort')
+    var body = AstFinder.getTopLevelFunction(unit, '_mergeSort')
         .functionExpression
-        .body as BlockFunctionBody);
+        .body as BlockFunctionBody;
     var stmts = body.block.statements;
     for (ExpressionStatement stmt in stmts) {
       MethodInvocation invoke = stmt.expression;
@@ -1317,9 +1317,9 @@ void _mergeSort<T>(T list, int compare(T a, T b), T target) {
     assertNoErrors(source);
     verify([source]);
     var unit = analysisResult.unit;
-    var body = (AstFinder.getTopLevelFunction(unit, '_mergeSort')
+    var body = AstFinder.getTopLevelFunction(unit, '_mergeSort')
         .functionExpression
-        .body as BlockFunctionBody);
+        .body as BlockFunctionBody;
     var stmts = body.block.statements;
     for (ExpressionStatement stmt in stmts) {
       MethodInvocation invoke = stmt.expression;

pkg/analyzer/test/src/dart/element/element_test.dart

@@ -2240,7 +2240,7 @@ class TypeParameterTypeImplTest extends AbstractTypeTest {
   void test_resolveToBound_bound_nullableInner() {
     ClassElementImpl classS = class_(name: 'A');
     TypeParameterElementImpl element = TypeParameterElementImpl('E', -1);
-    element.bound = (interfaceTypeQuestion(classS));
+    element.bound = interfaceTypeQuestion(classS);
     TypeParameterTypeImpl type = typeParameterTypeStar(element);
     expect(type.resolveToBound(null), same(element.bound));
   }

pkg/analyzer/test/utils.dart

@@ -220,7 +220,7 @@ class TypeAssertions {
   Asserter<DartType> isFunction2Of(
           Asserter<DartType> argType, Asserter<DartType> returnType) =>
       (DartType type) {
-        FunctionType fType = (type as FunctionType);
+        FunctionType fType = type as FunctionType;
         argType(fType.normalParameterTypes[0]);
         returnType(fType.returnType);
       };
@@ -230,7 +230,7 @@ class TypeAssertions {
   AsserterBuilder<List<Asserter<DartType>>, DartType> isInstantiationOf(
           Asserter<DartType> baseAssert) =>
       (List<Asserter<DartType>> argAsserts) => (DartType type) {
-            InterfaceType t = (type as InterfaceType);
+            InterfaceType t = type as InterfaceType;
             baseAssert(t);
             List<DartType> typeArguments = t.typeArguments;
             expect(typeArguments, hasLength(argAsserts.length));