gson-comments/gson/src/test/java/com/google/gson/regression/JsonAdapterNullSafeTest.java
Éamonn McManus c1da2d7070
Add @CanIgnoreReturnValue as appropriate to Gson methods. (#2369)
This annotation indicates that return value of the annotated method does
not need to be used. If it is _not_ present on a non-void method, and if
Error Prone's `CheckReturnValue` is active, then calling the method
without using the result is an error. However, we are not enabling
`CheckReturnValue` by default here.

Also update some code that does ignore return values, so that the
returned value is used, if only by assigning it to an unused variable.
2023-04-10 10:50:25 -07:00

65 lines
2.1 KiB
Java

/*
* Copyright (C) 2016 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.gson.regression;
import static com.google.common.truth.Truth.assertThat;
import com.google.gson.Gson;
import com.google.gson.TypeAdapter;
import com.google.gson.TypeAdapterFactory;
import com.google.gson.annotations.JsonAdapter;
import com.google.gson.reflect.TypeToken;
import org.junit.Test;
public class JsonAdapterNullSafeTest {
private final Gson gson = new Gson();
@Test
public void testNullSafeBugSerialize() {
Device device = new Device("ec57803e");
String unused = gson.toJson(device);
}
@Test
public void testNullSafeBugDeserialize() {
Device device = gson.fromJson("{'id':'ec57803e2'}", Device.class);
assertThat(device.id).isEqualTo("ec57803e2");
}
@JsonAdapter(Device.JsonAdapterFactory.class)
private static final class Device {
String id;
Device(String id) {
this.id = id;
}
static final class JsonAdapterFactory implements TypeAdapterFactory {
// The recursiveCall in {@link Device.JsonAdapterFactory} is the source of this bug
// because we use it to return a null type adapter on a recursive call.
private static final ThreadLocal<Boolean> recursiveCall = new ThreadLocal<>();
@Override public <T> TypeAdapter<T> create(final Gson gson, TypeToken<T> type) {
if (type.getRawType() != Device.class || recursiveCall.get() != null) {
recursiveCall.set(null); // clear for subsequent use
return null;
}
recursiveCall.set(Boolean.TRUE);
return gson.getDelegateAdapter(this, type);
}
}
}
}