1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
|
/*
* Copyright (C) 2014 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.inject;
import static org.junit.Assert.assertThrows;
import java.util.Collections;
import java.util.UUID;
import java.util.concurrent.Callable;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.function.Predicate;
import junit.framework.TestCase;
/**
* Test bindings to lambdas, method references, etc.
*
* @author cgdecker@google.com (Colin Decker)
*/
public class Java8LanguageFeatureBindingTest extends TestCase {
// Some of these tests are kind of weird.
// See https://github.com/google/guice/issues/757 for more on why they exist.
public void testBinding_lambdaToInterface() {
Injector injector =
Guice.createInjector(
new AbstractModule() {
@Override
protected void configure() {
bind(new TypeLiteral<Predicate<Object>>() {}).toInstance(o -> o != null);
}
});
Predicate<Object> predicate = injector.getInstance(new Key<Predicate<Object>>() {});
assertTrue(predicate.test(new Object()));
assertFalse(predicate.test(null));
}
public void testProviderMethod_returningLambda() throws Exception {
Injector injector =
Guice.createInjector(
new AbstractModule() {
@Provides
public Callable<String> provideCallable() {
return () -> "foo";
}
});
Callable<String> callable = injector.getInstance(new Key<Callable<String>>() {});
assertEquals("foo", callable.call());
}
public void testProviderMethod_containingLambda_throwingException() throws Exception {
Injector injector =
Guice.createInjector(
new AbstractModule() {
@Provides
public Callable<String> provideCallable() {
if (Boolean.parseBoolean("false")) { // avoid dead code warnings
return () -> "foo";
} else {
throw new RuntimeException("foo");
}
}
});
ProvisionException expected =
assertThrows(
ProvisionException.class, () -> injector.getInstance(new Key<Callable<String>>() {}));
assertTrue(expected.getCause() instanceof RuntimeException);
assertEquals("foo", expected.getCause().getMessage());
}
public void testProvider_usingJdk8Features() {
try {
Guice.createInjector(
new AbstractModule() {
@Override
protected void configure() {
bind(String.class).toProvider(StringProvider.class);
}
});
fail();
} catch (CreationException expected) {
}
UUID uuid = UUID.randomUUID();
Injector injector =
Guice.createInjector(
new AbstractModule() {
@Override
protected void configure() {
bind(UUID.class).toInstance(uuid);
bind(String.class).toProvider(StringProvider.class);
}
});
assertEquals(uuid.toString(), injector.getInstance(String.class));
}
private static final class StringProvider implements Provider<String> {
private final UUID uuid;
@Inject
StringProvider(UUID uuid) {
this.uuid = uuid;
}
@Override
public String get() {
return Collections.singleton(uuid).stream().map(UUID::toString).findFirst().get();
}
}
public void testBinding_toProvider_lambda() {
Injector injector =
Guice.createInjector(
new AbstractModule() {
@Override
protected void configure() {
AtomicInteger i = new AtomicInteger();
bind(String.class).toProvider(() -> "Hello" + i.incrementAndGet());
}
});
assertEquals("Hello1", injector.getInstance(String.class));
assertEquals("Hello2", injector.getInstance(String.class));
}
public void testBinding_toProvider_methodReference() {
Injector injector =
Guice.createInjector(
new AbstractModule() {
@Override
protected void configure() {
bind(String.class).toProvider(Java8LanguageFeatureBindingTest.this::provideString);
}
});
Provider<String> provider = injector.getProvider(String.class);
assertEquals("Hello", provider.get());
}
private String provideString() {
return "Hello";
}
}
|
