1/*
2 * Copyright (C) 2013 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.common.reflect;
18
19import junit.framework.TestCase;
20
21import java.lang.reflect.GenericArrayType;
22import java.lang.reflect.ParameterizedType;
23import java.lang.reflect.Type;
24import java.lang.reflect.TypeVariable;
25import java.lang.reflect.WildcardType;
26import java.util.ArrayList;
27import java.util.EnumSet;
28
29/**
30 * Tests of {@link TypeVisitor}.
31 *
32 * @author Ben Yu
33 */
34public class TypeVisitorTest extends TestCase {
35
36  public void testVisitNull() {
37    new BaseTypeVisitor().visit(
38        ((ParameterizedType) ArrayList.class.getGenericSuperclass()).getOwnerType());
39  }
40
41  public void testVisitClass() {
42    assertVisited(String.class);
43    new BaseTypeVisitor() {
44      @Override void visitClass(Class<?> t) {}
45    }.visit(String.class);
46  }
47
48  public <T> void testVisitTypeVariable() {
49    Type type = new TypeCapture<T>() {}.capture();
50    assertVisited(type);
51    new BaseTypeVisitor() {
52      @Override void visitTypeVariable(TypeVariable<?> t) {}
53    }.visit(type);
54  }
55
56  public void testVisitWildcardType() {
57    WildcardType type = Types.subtypeOf(String.class);
58    assertVisited(type);
59    new BaseTypeVisitor() {
60      @Override void visitWildcardType(WildcardType t) {}
61    }.visit(type);
62  }
63
64  public <T> void testVisitGenericArrayType() {
65    Type type = new TypeCapture<T[]>() {}.capture();
66    assertVisited(type);
67    new BaseTypeVisitor() {
68      @Override void visitGenericArrayType(GenericArrayType t) {}
69    }.visit(type);
70  }
71
72  public <T> void testVisitParameterizedType() {
73    Type type = new TypeCapture<Iterable<T>>() {}.capture();
74    assertVisited(type);
75    new BaseTypeVisitor() {
76      @Override void visitParameterizedType(ParameterizedType t) {}
77    }.visit(type);
78  }
79
80  public <E extends Enum<E>> void testVisitRecursiveTypeBounds() {
81    Type type = new TypeCapture<EnumSet<E>>() {}.capture();
82    assertVisited(type);
83    new BaseTypeVisitor() {
84      @Override void visitParameterizedType(ParameterizedType t) {
85        visit(t.getActualTypeArguments());
86      }
87      @Override void visitTypeVariable(TypeVariable<?> t) {
88        visit(t.getBounds());
89      }
90    }.visit(type);
91  }
92
93  private static void assertVisited(Type type) {
94    TypeVisitor visitor = new BaseTypeVisitor();
95    try {
96      visitor.visit(type);
97      fail("Type not visited");
98    } catch (UnsupportedOperationException expected) {}
99    try {
100      visitor.visit(new Type[] {type});
101      fail("Type not visited");
102    } catch (UnsupportedOperationException expected) {}
103  }
104
105  private static class BaseTypeVisitor extends TypeVisitor {
106    @Override void visitTypeVariable(TypeVariable<?> t) {
107      throw new UnsupportedOperationException();
108    }
109
110    @Override void visitWildcardType(WildcardType t) {
111      throw new UnsupportedOperationException();
112    }
113
114    @Override void visitParameterizedType(ParameterizedType t) {
115      throw new UnsupportedOperationException();
116    }
117
118    @Override void visitClass(Class<?> t) {
119      throw new UnsupportedOperationException();
120    }
121
122    @Override void visitGenericArrayType(GenericArrayType t) {
123      throw new UnsupportedOperationException();
124    }
125  }
126}
127