com.google.errorprone.bugpatterns.MultipleUnaryOperatorsInMethodCall Maven / Gradle / Ivy
/*
* Copyright 2017 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.errorprone.BugPattern.SeverityLevel.WARNING;
import static com.google.errorprone.matchers.Description.NO_MATCH;
import static java.util.stream.Collectors.groupingBy;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Sets;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.MethodInvocationTree;
import com.sun.source.tree.Tree.Kind;
import com.sun.source.tree.UnaryTree;
import java.util.function.Function;
import java.util.stream.Collectors;
/** @author [email protected] (Marsela Sulku) */
@BugPattern(
name = "MultipleUnaryOperatorsInMethodCall",
summary = "Avoid having multiple unary operators acting on the same variable in a method call",
severity = WARNING)
public class MultipleUnaryOperatorsInMethodCall extends BugChecker
implements MethodInvocationTreeMatcher {
private static final ImmutableSet UNARY_OPERATORS =
Sets.immutableEnumSet(
Kind.POSTFIX_DECREMENT,
Kind.POSTFIX_INCREMENT,
Kind.PREFIX_DECREMENT,
Kind.PREFIX_INCREMENT);
@Override
public Description matchMethodInvocation(
MethodInvocationTree methodInvocationTree, VisitorState visitorState) {
if (methodInvocationTree.getArguments().stream()
.filter(arg -> UNARY_OPERATORS.contains(arg.getKind()))
.map(arg -> ASTHelpers.getSymbol(((UnaryTree) arg).getExpression()))
.filter(sym -> sym != null)
.collect(groupingBy(Function.identity(), Collectors.counting()))
.entrySet()
.stream()
.anyMatch(e -> e.getValue() > 1)) {
return describeMatch(methodInvocationTree);
}
return NO_MATCH;
}
}