In constant evaluation, properly handle redirecting factory constructors.

editor/tools/plugins/com.google.dart.engine_test/src/com/google/dart/engine/internal/constant/ConstantVisitorTest.java

Index: editor/tools/plugins/com.google.dart.engine_test/src/com/google/dart/engine/internal/constant/ConstantVisitorTest.java
diff --git a/editor/tools/plugins/com.google.dart.engine_test/src/com/google/dart/engine/internal/constant/ConstantVisitorTest.java b/editor/tools/plugins/com.google.dart.engine_test/src/com/google/dart/engine/internal/constant/ConstantVisitorTest.java
index af286f60f3b8e146893d60f4fb9b1d83296d82a3..14e511e6f0b5efd973cadbfc19d8e8c4138eda6a 100644
--- a/editor/tools/plugins/com.google.dart.engine_test/src/com/google/dart/engine/internal/constant/ConstantVisitorTest.java
+++ b/editor/tools/plugins/com.google.dart.engine_test/src/com/google/dart/engine/internal/constant/ConstantVisitorTest.java
@@ -13,11 +13,16 @@
  */
 package com.google.dart.engine.internal.constant;
 
-import com.google.dart.engine.EngineTestCase;
+import com.google.dart.engine.ast.CompilationUnit;
+import com.google.dart.engine.ast.CompilationUnitMember;
 import com.google.dart.engine.ast.ConditionalExpression;
 import com.google.dart.engine.ast.Expression;
 import com.google.dart.engine.ast.InstanceCreationExpression;
+import com.google.dart.engine.ast.TopLevelVariableDeclaration;
+import com.google.dart.engine.ast.VariableDeclaration;
+import com.google.dart.engine.context.AnalysisException;
 import com.google.dart.engine.element.ClassElement;
+import com.google.dart.engine.element.LibraryElement;
 import com.google.dart.engine.internal.element.ClassElementImpl;
 import com.google.dart.engine.internal.element.CompilationUnitElementImpl;
 import com.google.dart.engine.internal.element.ConstructorElementImpl;
@@ -25,7 +30,9 @@ import com.google.dart.engine.internal.element.FieldFormalParameterElementImpl;
 import com.google.dart.engine.internal.element.LibraryElementImpl;
 import com.google.dart.engine.internal.object.DartObjectImpl;
 import com.google.dart.engine.internal.resolver.TestTypeProvider;
+import com.google.dart.engine.resolver.ResolverTestCase;
 import com.google.dart.engine.scanner.Keyword;
+import com.google.dart.engine.source.Source;
 
 import static com.google.dart.engine.ast.AstFactory.booleanLiteral;
 import static com.google.dart.engine.ast.AstFactory.conditionalExpression;
@@ -38,7 +45,7 @@ import static com.google.dart.engine.element.ElementFactory.classElement;
 import static com.google.dart.engine.element.ElementFactory.constructorElement;
 import static com.google.dart.engine.element.ElementFactory.library;
 
-public class ConstantVisitorTest extends EngineTestCase {
+public class ConstantVisitorTest extends ResolverTestCase {
   public void test_visitConditionalExpression_false() {
     Expression thenExpression = integer(1L);
     Expression elseExpression = integer(0L);
@@ -112,10 +119,101 @@ public class ConstantVisitorTest extends EngineTestCase {
     assertValue(1L, expression.accept(new ConstantVisitor(new TestTypeProvider())));
   }
 
+  public void test_visitInstanceCreationExpression_redirect() throws Exception {
+    CompilationUnit compilationUnit = resolveSource(createSource(//
+        "const foo = const A();",
+        "class A {",
+        "  const factory A() = B;",
+        "}",
+        "class B implements A {",
+        "  const B();",
+        "}"));
+    assertType(evaluateConstant(compilationUnit, "foo"), "B");
+  }
+
+  public void test_visitInstanceCreationExpression_redirect_cycle() throws Exception {
+    // It is an error to have a cycle in factory redirects; however, we need
+    // to make sure that even if the error occurs, attempting to evaluate the
+    // constant will terminate.
+    CompilationUnit compilationUnit = resolveSource(createSource(//
+        "const foo = const A();",
+        "class A {",
+        "  const factory A() = A.b;",
+        "  const factory A.b() = A;",
+        "}"));
+    assertError(evaluateConstant(compilationUnit, "foo"));
+  }
+
+  public void test_visitInstanceCreationExpression_redirect_extern() throws Exception {
+    CompilationUnit compilationUnit = resolveSource(createSource(//
+        "const foo = const A();",
+        "class A {",
+        "  external const factory A();",
+        "}"));
+    assertError(evaluateConstant(compilationUnit, "foo"));
+  }
+
+  public void test_visitInstanceCreationExpression_redirect_nonConst() throws Exception {
+    // It is an error for a const factory constructor redirect to a non-const
+    // constructor; however, we need to make sure that even if the error
+    // attempting to evaluate the constant won't cause a crash.
+    CompilationUnit compilationUnit = resolveSource(createSource(//
+        "const foo = const A();",
+        "class A {",
+        "  const factory A() = A.b;",
+        "  A.b();",
+        "}"));
+    assertError(evaluateConstant(compilationUnit, "foo"));
+  }
+
+  public void test_visitInstanceCreationExpression_symbol() throws Exception {
+    CompilationUnit compilationUnit = resolveSource(createSource("const foo = const Symbol('a');"));
+    EvaluationResultImpl evaluationResult = evaluateConstant(compilationUnit, "foo");
+    assertInstanceOf(ValidResult.class, evaluationResult);
+    DartObjectImpl value = ((ValidResult) evaluationResult).getValue();
+    assertEquals(getTypeProvider().getSymbolType(), value.getType());
+    assertEquals("a", value.getValue());
+  }
+
+  private void assertError(EvaluationResultImpl result) {
+    assertInstanceOf(ErrorResult.class, result);
+  }
+
+  private void assertType(EvaluationResultImpl result, String typeName) {
+    assertInstanceOf(ValidResult.class, result);
+    DartObjectImpl value = ((ValidResult) result).getValue();
+    assertEquals(typeName, value.getType().getName());
+  }
+
   private void assertValue(long expectedValue, EvaluationResultImpl result) {
     assertInstanceOf(ValidResult.class, result);
     DartObjectImpl value = ((ValidResult) result).getValue();
     assertEquals("int", value.getType().getName());
     assertEquals(expectedValue, value.getIntValue().longValue());
   }
+
+  private EvaluationResultImpl evaluateConstant(CompilationUnit compilationUnit, String name)
+      throws AnalysisException {
+    Expression expression = findTopLevelConstantExpression(compilationUnit, name);
+    return expression.accept(new ConstantVisitor(getTypeProvider()));
+  }
+
+  private Expression findTopLevelConstantExpression(CompilationUnit compilationUnit, String name) {
+    for (CompilationUnitMember member : compilationUnit.getDeclarations()) {
+      if (member instanceof TopLevelVariableDeclaration) {
+        for (VariableDeclaration variable : ((TopLevelVariableDeclaration) member).getVariables().getVariables()) {
+          if (variable.getName().getName().equals(name)) {
+            return variable.getInitializer();
+          }
+        }
+      }
+    }
+    return null; // Not found
+  }
+
+  private CompilationUnit resolveSource(String sourceText) throws AnalysisException {
+    Source source = addSource(sourceText);
+    LibraryElement library = getAnalysisContext().computeLibraryElement(source);
+    return getAnalysisContext().resolveCompilationUnit(source, library);
+  }
 }