Strong mode local variable inference

pkg/analyzer/test/generated/resolver_test.dart

 // Copyright (c) 2014, 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 engine.resolver_test;
 
 import 'dart:collection';
 
 import 'package:analyzer/src/context/context.dart' as newContext;
 import 'package:analyzer/src/generated/ast.dart';
@@ skipping 50 matching lines @@
   runReflectiveTests(TypeProviderImplTest);
   runReflectiveTests(TypeResolverVisitorTest);
   runReflectiveTests(CheckedModeCompileTimeErrorCodeTest);
   runReflectiveTests(ErrorResolverTest);
   runReflectiveTests(HintCodeTest);
   runReflectiveTests(MemberMapTest);
   runReflectiveTests(NonHintCodeTest);
   runReflectiveTests(SimpleResolverTest);
   runReflectiveTests(StrictModeTest);
   runReflectiveTests(TypePropagationTest);
+  runReflectiveTests(StrongModeTypePropagationTest);
 }
 
 /**
  * The class `AnalysisContextFactory` defines utility methods used to create analysis contexts
  * for testing purposes.
  */
 class AnalysisContextFactory {
   static String _DART_MATH = "dart:math";
 
   static String _DART_INTERCEPTORS = "dart:_interceptors";
@@ skipping 13463 matching lines @@
       // assertion failure here should be a failure, in both "test_*" and
       // "fail_*" tests. However, an assertion failure is success for the
       // purpose of "fail_*" tests, so without catching them here "fail_*" tests
       // can succeed by failing for the wrong reason.
       throw new JavaException("Unexexpected assertion failure: $exception");
     }
   }
 }
 
 @reflectiveTest
+class StrongModeTypePropagationTest extends TypePropagationTest {
+  void _enterStrongMode() {

[Paul Berry, 2015/08/27 01:28:11]

Consider renaming this method to setUp() and adding an "@override" declaration. 
That way it will be automatically called just before every test, so you can drop
all the explicit calls to it.

[Leaf, 2015/08/27 18:15:26]

This reveals an issue, actually.  I made StrongModeTypePropagationTest a
subclass of TypePropagationTest mostly just to get access to the
_findMarkedIdentifier and a few other helpers.  I just realized though that this
results in all of the superclass tests being re-run, which I probably don't want
(and certainly don't want to happen with the strongMode flag set).  

I've moved those helpers up to ResolverTestCase and made
StrongModeTypePropagationTest a direct subclass, which seems like a reasonable
place for them to reside.  I also renamed _assertPropagatedReturnType to
_assertPropagatedAssignedType, since that seems to be are more accurate name. 
WDYT?

+    AnalysisOptionsImpl options = new AnalysisOptionsImpl();
+    options.strongMode = true;
+    resetWithOptions(options);
+  }
+
+  void test_localVariableInference_constant() {
+    _enterStrongMode();
+    String code = r'''
+main() {
+  var v = 3;
+  return v; // marker
+}''';
+    _assertPropagatedReturnType(code, typeProvider.intType, null);
+    _assertTypeOfMarkedExpression(code, typeProvider.intType, null);
+  }
+
+  void test_localVariableInference_transitive_local() {
+    _enterStrongMode();
+    String code = r'''
+main() {
+  var x = 3;
+  var v = x;
+  return v; // marker
+}''';
+    _assertPropagatedReturnType(code, typeProvider.intType, null);
+    _assertTypeOfMarkedExpression(code, typeProvider.intType, null);
+  }
+
+  void test_localVariableInference_transitive_list_local() {
+    _enterStrongMode();
+    String code = r'''
+main() {
+  var x = <int>[3];
+  var v = x[0];
+  return v; // marker
+}''';
+    _assertPropagatedReturnType(code, typeProvider.intType, null);
+    _assertTypeOfMarkedExpression(code, typeProvider.intType, null);
+  }
+
+  void test_localVariableInference_transitive_toplevel_lexical() {
+    _enterStrongMode();
+    String code = r'''
+int x = 3;
+main() {
+  var v = x;
+  return v; // marker
+}
+''';
+    _assertPropagatedReturnType(code, typeProvider.intType, null);
+    _assertTypeOfMarkedExpression(code, typeProvider.intType, null);
+  }
+
+  void test_localVariableInference_transitive_toplevel_reversed() {
+    _enterStrongMode();
+    String code = r'''
+main() {
+  var v = x;
+  return v; // marker
+}
+int x = 3;
+''';
+    _assertPropagatedReturnType(code, typeProvider.intType, null);
+    _assertTypeOfMarkedExpression(code, typeProvider.intType, null);
+  }
+
+  void fail_localVariableInference_transitive_toplevel_inferred_lexical() {
+    _enterStrongMode();
+    String code = r'''
+final x = 3;
+main() {
+  var v = x;
+  return v; // marker
+}
+''';
+    _assertPropagatedReturnType(code, typeProvider.intType, null);
+    _assertTypeOfMarkedExpression(code, typeProvider.intType, null);
+  }
+
+  void fail_localVariableInference_transitive_toplevel_inferred_reversed() {
+    _enterStrongMode();
+    String code = r'''
+main() {
+  var v = x;
+  return v; // marker
+}
+final x = 3;
+''';
+    _assertPropagatedReturnType(code, typeProvider.intType, null);
+    _assertTypeOfMarkedExpression(code, typeProvider.intType, null);
+  }
+
+  void test_localVariableInference_transitive_field_lexical() {
+    _enterStrongMode();
+    String code = r'''
+class A {
+  int x = 3;
+  f() {
+    var v = x;
+    return v; // marker
+  }
+}
+main() {
+}
+''';
+    _assertPropagatedReturnType(code, typeProvider.intType, null);
+    _assertTypeOfMarkedExpression(code, typeProvider.intType, null);
+  }
+
+  void test_localVariableInference_transitive_field_reversed() {
+    _enterStrongMode();
+    String code = r'''
+class A {
+  f() {
+    var v = x;
+    return v; // marker
+  }
+  int x = 3;
+}
+main() {
+}
+''';
+    _assertPropagatedReturnType(code, typeProvider.intType, null);
+    _assertTypeOfMarkedExpression(code, typeProvider.intType, null);
+  }
+
+  void fail_localVariableInference_transitive_field_inferred_lexical() {
+    _enterStrongMode();
+    String code = r'''
+class A {
+  final x = 3;
+  f() {
+    var v = x;
+    return v; // marker
+  }
+}
+main() {
+}
+''';
+    _assertPropagatedReturnType(code, typeProvider.intType, null);
+    _assertTypeOfMarkedExpression(code, typeProvider.intType, null);
+  }
+
+  void fail_localVariableInference_transitive_field_inferred_reversed() {
+    _enterStrongMode();
+    String code = r'''
+class A {
+  f() {
+    var v = x;
+    return v; // marker
+  }
+  final x = 3;
+}
+main() {
+}
+''';
+    _assertPropagatedReturnType(code, typeProvider.intType, null);
+    _assertTypeOfMarkedExpression(code, typeProvider.intType, null);
+  }
+
+  void test_localVariableInference_declaredType_disabled() {
+    _enterStrongMode();
+    String code = r'''
+main() {
+  dynamic v = 3;
+  return v; // marker
+}''';
+    _assertPropagatedReturnType(
+        code, typeProvider.dynamicType, typeProvider.intType);
+    _assertTypeOfMarkedExpression(
+        code, typeProvider.dynamicType, typeProvider.intType);
+  }
+
+  void test_localVariableInference_bottom_disabled() {
+    _enterStrongMode();
+    String code = r'''
+main() {
+  var v = null;
+  return v; // marker
+}''';
+    _assertPropagatedReturnType(code, typeProvider.dynamicType, null);
+    _assertTypeOfMarkedExpression(code, typeProvider.dynamicType, null);
+  }
+
+  void test_localVariableInference_noInitializer_disabled() {
+    _enterStrongMode();
+    String code = r'''
+main() {
+  var v;
+  v = 3;
+  return v; // marker
+}''';
+    _assertPropagatedReturnType(
+        code, typeProvider.dynamicType, typeProvider.intType);
+    _assertTypeOfMarkedExpression(
+        code, typeProvider.dynamicType, typeProvider.intType);
+  }
+}
+
+@reflectiveTest
 class TypeProviderImplTest extends EngineTestCase {
   void test_creation() {
     //
     // Create a mock library element with the types expected to be in dart:core.
     // We cannot use either ElementFactory or TestTypeProvider (which uses
     // ElementFactory) because we side-effect the elements in ways that would
     // break other tests.
     //
     InterfaceType objectType = _classElement("Object", null).type;
     InterfaceType boolType = _classElement("bool", objectType).type;
@@ skipping 763 matching lines @@
         // check propagated type
         FunctionType propagatedType = node.propagatedType as FunctionType;
         expect(propagatedType.returnType, test.typeProvider.stringType);
       } on AnalysisException catch (e, stackTrace) {
         thrownException[0] = new CaughtException(e, stackTrace);
       }
     }
     return null;
   }
 }