org.codenarc.rule.groovyism.ClosureAsLastMethodParameterRule.groovy Maven / Gradle / Ivy

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/*
 * Copyright 2011 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.groovyism

import org.codehaus.groovy.ast.expr.ClosureExpression
import org.codehaus.groovy.ast.expr.MethodCallExpression
import org.codenarc.rule.AbstractAstVisitorRule
import org.codenarc.rule.AbstractMethodCallExpressionVisitor
import org.codenarc.util.AstUtil

/**
 * If a method is called and the last parameter is an inline closure it can be declared outside of the method call brackets.
 *
 * @author Marcin Erdmann
 * @Chris Mair
 */
class ClosureAsLastMethodParameterRule extends AbstractAstVisitorRule {
    String name = 'ClosureAsLastMethodParameter'
    int priority = 3
    Class astVisitorClass = ClosureAsLastMethodParameterAstVisitor
}

class ClosureAsLastMethodParameterAstVisitor extends AbstractMethodCallExpressionVisitor {

    @Override
    void visitMethodCallExpression(MethodCallExpression call) {
        def arguments = AstUtil.getMethodArguments(call)
        if (arguments && arguments.last() instanceof ClosureExpression) {

            def lastArgument = arguments.last()
            def sourceLine = sourceCode.lines[call.lineNumber - 1]
            def firstChar = sourceLine[call.columnNumber - 1]

            // If a method call is surrounded by parentheses (possibly unnecessary), then the AST includes those in the
            // MethodCall start/end column indexes. In that case, it gets too complicated. Just bail.
            if (firstChar == '(') {
                super.visitMethodCallExpression(call)
                return
            }

            def isViolation = call.lastLineNumber > lastArgument.lastLineNumber ||
                (call.lastLineNumber == lastArgument.lastLineNumber &&
                    call.lastColumnNumber > lastArgument.lastColumnNumber)

            if (isViolation) {
                addViolation(call, "The last parameter to the '$call.methodAsString' method call is a closure an can appear outside the parenthesis")
            }
        }
    }

}