Infer setter parameter types in strong mode

pkg/analyzer/test/src/task/strong_mode_test.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library test.src.task.strong_mode_test;
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/task/strong_mode.dart';
@@ skipping 440 matching lines @@
     String getterName = 'g';
     CompilationUnitElement unit = resolve('''
 class A {
   int get $getterName => 0;
   set $getterName(String value) {}
 }
 class B extends A {
   var get $getterName => 1;
 }
 ''');
+    ClassElement classA = unit.getType('A');
+    FieldElement fieldA = classA.getField(getterName);
+    PropertyAccessorElement getterA = classA.getGetter(getterName);
     ClassElement classB = unit.getType('B');
     FieldElement fieldB = classB.getField(getterName);
     PropertyAccessorElement getterB = classB.getGetter(getterName);
     expect(fieldB.type.isDynamic, isTrue);
     expect(getterB.returnType.isDynamic, isTrue);
 
     inferrer.inferCompilationUnit(unit);
 
+    // Expected behavior is that the getter is inferred: getters and setters
+    // are treated as independent methods.
+    expect(fieldB.type, fieldA.type);
+    expect(getterB.returnType, getterA.returnType);
+  }
+
+  void test_inferCompilationUnit_setter_single() {
+    InstanceMemberInferrer inferrer = createInferrer;
+    String setterName = 'g';
+    CompilationUnitElement unit = resolve('''
+class A {
+  set $setterName(int x) {}
+}
+class B extends A {
+  set $setterName(x) {}
+}
+''');
+    ClassElement classA = unit.getType('A');
+    FieldElement fieldA = classA.getField(setterName);
+    PropertyAccessorElement setterA = classA.getSetter(setterName);
+    ClassElement classB = unit.getType('B');
+    FieldElement fieldB = classB.getField(setterName);
+    PropertyAccessorElement setterB = classB.getSetter(setterName);
     expect(fieldB.type.isDynamic, isTrue);
-    expect(getterB.returnType.isDynamic, isTrue);
+    expect(setterB.parameters[0].type.isDynamic, isTrue);
+
+    inferrer.inferCompilationUnit(unit);
+
+    expect(fieldB.type, fieldA.type);
+    expect(setterB.parameters[0].type, setterA.parameters[0].type);
+  }
+
+  void test_inferCompilationUnit_setter_single_generic() {
+    InstanceMemberInferrer inferrer = createInferrer;
+    String setterName = 'g';
+    CompilationUnitElement unit = resolve('''
+class A<E> {
+  set $setterName(E x) {}
+}
+class B<E> extends A<E> {
+  set $setterName(x) {}
+}
+''');
+    ClassElement classB = unit.getType('B');
+    DartType typeBE = classB.typeParameters[0].type;
+    FieldElement fieldB = classB.getField(setterName);
+    PropertyAccessorElement setterB = classB.getSetter(setterName);
+    expect(fieldB.type.isDynamic, isTrue);
+    expect(setterB.parameters[0].type.isDynamic, isTrue);
+
+    inferrer.inferCompilationUnit(unit);
+
+    expect(fieldB.type, typeBE);
+    expect(setterB.parameters[0].type, typeBE);
+  }
+
+  void test_inferCompilationUnit_setter_single_inconsistentAccessors() {
+    InstanceMemberInferrer inferrer = createInferrer;
+    String getterName = 'g';
+    CompilationUnitElement unit = resolve('''
+class A {
+  int get $getterName => 0;
+  set $getterName(String value) {}
+}
+class B extends A {
+  set $getterName(x) {}
+}
+''');
+    ClassElement classA = unit.getType('A');
+    FieldElement fieldA = classA.getField(getterName);
+    PropertyAccessorElement setterA = classA.getSetter(getterName);
+    ClassElement classB = unit.getType('B');
+    FieldElement fieldB = classB.getField(getterName);
+    PropertyAccessorElement setterB = classB.getSetter(getterName);
+    expect(fieldB.type.isDynamic, isTrue);
+    expect(setterB.parameters[0].type.isDynamic, isTrue);
+
+    inferrer.inferCompilationUnit(unit);
+
+    // Expected behavior is that the getter is inferred: getters and setters
+    // are treated as independent methods.
+    expect(setterB.parameters[0].type, setterA.parameters[0].type);
+
+    // Note that B's synthetic field type will be String. This matches what
+    // resolver would do if we explicitly typed the parameter as 'String'
+    expect(fieldB.type, setterB.parameters[0].type);
   }
 
   void test_inferCompilationUnit_invalid_inheritanceCycle() {
     InstanceMemberInferrer inferrer = createInferrer;
     CompilationUnitElement unit = resolve('''
 class A extends C {}
 class B extends A {}
 class C extends B {}
 ''');
     inferrer.inferCompilationUnit(unit);
@@ skipping 419 matching lines @@
     }
   }
 }
 ''');
     CompilationUnit unit = context.resolveCompilationUnit2(source, source);
     VariableGatherer gatherer = new VariableGatherer(filter);
     unit.accept(gatherer);
     return gatherer.results;
   }
 }