org.codenarc.rule.unused.UnusedPrivateFieldRule.groovy Maven / Gradle / Ivy

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The CodeNarc project provides a static analysis tool for Groovy code.
There is a newer version: 3.5.0-groovy-4.0
/*
 * 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.unused

import org.codehaus.groovy.ast.ClassNode
import org.codehaus.groovy.ast.FieldNode
import org.codehaus.groovy.ast.ModuleNode
import org.codenarc.rule.AbstractSharedAstVisitorRule
import org.codenarc.rule.AstVisitor
import org.codenarc.rule.ConstructorsSkippingFieldReferenceAstVisitor
import org.codenarc.rule.FieldReferenceAstVisitor
import org.codenarc.rule.Violation
import org.codenarc.source.SourceCode
import org.codenarc.util.AstUtil
import org.codenarc.util.WildcardPattern

/**
 * Rule that checks for private fields that are not referenced within the same class.
 * 
 * Ignore fields annotated with @Delegate.
 * 

 * The ignoreFieldNames property optionally specifies one or more
 * (comma-separated) field names that should be ignored (i.e., that should not cause a
 * rule violation). The name(s) may optionally include wildcard characters ('*' or '?').
 * 
 * The ignoreClassesAnnotatedWithNames property optionally specifies one or more
 * (comma-separated) annotation names; any classes annotated with those should be ignored (i.e., should not cause a
 * rule violation). The name(s) may optionally include wildcard characters ('*' or '?').
 *
 * @author Chris Mair
 * @author Hamlet D'Arcy
 */
class UnusedPrivateFieldRule extends AbstractSharedAstVisitorRule {

    String name = 'UnusedPrivateField'
    int priority = 2
    String ignoreFieldNames = 'serialVersionUID'
    boolean allowConstructorOnlyUsages = true
    String ignoreClassesAnnotatedWithNames = 'Entity'

    @Override
    protected boolean shouldApplyThisRuleTo(ClassNode classNode) {
        if (ignoreClassesAnnotatedWithNames) {
            def wildcardPattern = new WildcardPattern(ignoreClassesAnnotatedWithNames, false)
            boolean ignore = classNode.annotations.find { annotationNode -> wildcardPattern.matches(annotationNode.classNode.nameWithoutPackage) }
            if (ignore) {
                return false
            }
        }
        return super.shouldApplyThisRuleTo(classNode)
    }

    @Override
    protected AstVisitor getAstVisitor(SourceCode sourceCode) {
        def allPrivateFields = collectAllPrivateFields(sourceCode.ast)
        return allowConstructorOnlyUsages ?
                new FieldReferenceAstVisitor(allPrivateFields) :
                new ConstructorsSkippingFieldReferenceAstVisitor(allPrivateFields)
    }

    @Override
    protected List getViolations(AstVisitor visitor, SourceCode sourceCode) {
        visitor.unreferencedFields.each { FieldNode fieldNode ->
            visitor.addViolation(fieldNode, "The field ${fieldNode.name} is not used within the class ${fieldNode.owner?.name}")
        }
        return visitor.violations
    }

    @SuppressWarnings('NestedBlockDepth')
    private List collectAllPrivateFields(ModuleNode ast) {
        def allPrivateFields = []
        ast.classes.each { classNode ->
            if (shouldApplyThisRuleTo(classNode)) {
                classNode.fields.inject(allPrivateFields) { acc, fieldNode ->
                    def wildcardPattern = new WildcardPattern(ignoreFieldNames, false)
                    def isPrivate = fieldNode.isPrivate()
                    def isNotGenerated = fieldNode.lineNumber != -1
                    def isIgnored = wildcardPattern.matches(fieldNode.name)
                    def hasDelegateAnnotation = AstUtil.hasAnnotation(fieldNode, 'Delegate') || AstUtil.hasAnnotation(fieldNode, 'groovy.lang.Delegate')
                    if (isPrivate && isNotGenerated && !isIgnored && !hasDelegateAnnotation) {
                        acc << fieldNode
                    }
                    acc
                }
            }
        }
        allPrivateFields
    }
}