org.codenarc.rule.basic.EqualsAndHashCodeRule.groovy Maven / Gradle / Ivy
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The CodeNarc project provides a static analysis tool for Groovy code.
/*
* Copyright 2009 the original author or 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 org.codenarc.rule.basic
import org.codehaus.groovy.ast.ClassNode
import org.codenarc.rule.AbstractAstVisitor
import org.codenarc.rule.AbstractAstVisitorRule
/**
* Rule that checks that if either the boolean equals(Object) or
* the int hashCode() methods are overridden within a class, then both must be overridden.
*
* @author Chris Mair
* @author Hamlet D'Arcy
*/
class EqualsAndHashCodeRule extends AbstractAstVisitorRule {
String name = 'EqualsAndHashCode'
int priority = 2
Class astVisitorClass = EqualsAndHashCodeAstVisitor
}
class EqualsAndHashCodeAstVisitor extends AbstractAstVisitor {
@Override
void visitClassEx(ClassNode classNode) {
def methods = classNode.methods
def equalsMethod = methods.find { m ->
m.name == 'equals' &&
m.parameters.size() == 1 &&
m.parameters[0].type.name in ['Object', 'java.lang.Object']
}
def hashCodeMethod = methods.find { m -> m.name == 'hashCode' && m.parameters.size() == 0 }
def oneButNotBoth = (equalsMethod || hashCodeMethod) && !(equalsMethod && hashCodeMethod)
if (oneButNotBoth) {
if (equalsMethod) {
addViolation(classNode, "The class $classNode.name defines equals(Object) but not hashCode()")
} else {
addViolation(classNode, "The class $classNode.name defines hashCode() but not equals(Object)")
}
}
super.visitClassEx(classNode)
}
}