com.google.errorprone.bugpatterns.AbstractAsyncTypeReturnsNull Maven / Gradle / Ivy
/*
* Copyright 2015 The Error Prone Authors.
*
* 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.errorprone.bugpatterns;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.errorprone.util.ASTHelpers.findSuperMethods;
import static com.google.errorprone.util.ASTHelpers.getSymbol;
import com.google.common.util.concurrent.Futures;
import com.google.errorprone.VisitorState;
import com.google.errorprone.fixes.Fix;
import com.google.errorprone.fixes.SuggestedFix;
import com.google.errorprone.matchers.Matcher;
import com.sun.source.tree.MethodTree;
import com.sun.source.tree.ReturnTree;
import com.sun.tools.javac.code.Symbol.MethodSymbol;
import java.util.Optional;
/**
* Superclass for checks that {@code AsyncCallable} and {@code AsyncFunction} implementations do not
* directly {@code return null}.
*/
abstract class AbstractAsyncTypeReturnsNull extends AbstractMethodReturnsNull {
AbstractAsyncTypeReturnsNull(Class asyncClass) {
super(overridesMethodOfClass(asyncClass));
}
@Override
protected Optional provideFix(ReturnTree tree) {
return Optional.of(
SuggestedFix.builder()
.replace(tree.getExpression(), "immediateFuture(null)")
.addStaticImport(Futures.class.getName() + ".immediateFuture")
.build());
}
private static Matcher overridesMethodOfClass(final Class clazz) {
checkNotNull(clazz);
return new Matcher() {
@Override
public boolean matches(MethodTree tree, VisitorState state) {
MethodSymbol symbol = getSymbol(tree);
if (symbol == null) {
return false;
}
for (MethodSymbol superMethod : findSuperMethods(symbol, state.getTypes())) {
if (superMethod.owner != null
&& superMethod.owner.getQualifiedName().contentEquals(clazz.getName())) {
return true;
}
}
return false;
}
};
}
}