RecordComponentNumberCheck.java
////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2021 the original author or authors.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
////////////////////////////////////////////////////////////////////////////////
package com.puppycrawl.tools.checkstyle.checks.sizes;
import java.util.Arrays;
import java.util.concurrent.atomic.AtomicInteger;
import com.puppycrawl.tools.checkstyle.StatelessCheck;
import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
import com.puppycrawl.tools.checkstyle.checks.naming.AccessModifierOption;
import com.puppycrawl.tools.checkstyle.utils.CheckUtil;
import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
/**
* <p>
* Checks the number of record components in the
* <a href="https://docs.oracle.com/javase/specs/jls/se14/preview/specs/records-jls.html#jls-8.10.1">
* header</a> of a record definition.
* </p>
* <ul>
* <li>
* Property {@code max} - Specify the maximum number of components allowed in the header of a
* record definition.
* Type is {@code int}.
* Default value is {@code 8}.
* </li>
* <li>
* Property {@code accessModifiers} - Access modifiers of record definitions where
* the number of record components should be checked.
* Type is {@code com.puppycrawl.tools.checkstyle.checks.naming.AccessModifierOption[]}.
* Default value is {@code public, protected, package, private}.
* </li>
* </ul>
* <p>
* To configure the check:
* </p>
* <pre>
* <module name="RecordComponentNumber"/>
* </pre>
* <p>
* Java code example:
* </p>
* <pre>
* public record MyRecord1(int x, int y) { // ok, 2 components
* ...
* }
*
* record MyRecord2(int x, int y, String str,
* Node node, Order order, Data data
* String location, Date date, Image image) { // violation, 9 components
* ...
* }
* </pre>
* <p>
* To configure the check to allow 5 record components at all access modifier levels
* for record definitions:
* </p>
* <pre>
* <module name="RecordComponentNumber">
* <property name="max" value="5"/>
* </module>
* </pre>
* <p>
* Java code example:
* </p>
* <pre>
* public record MyRecord1(int x, int y, String str) { // ok, 3 components
* ...
* }
*
* public record MyRecord2(int x, int y, String str,
* Node node, Order order, Data data) { // violation, 6 components
* ...
* }
* </pre>
* <p>
* To configure the check to allow 10 record components for a public record definition,
* but 3 for private record definitions:
* </p>
* <pre>
* <module name="RecordComponentNumber">
* <property name="max" value="3"/>
* <property name="accessModifiers" value="private"/>
* </module>
* <module name="RecordComponentNumber">
* <property name="max" value="10"/>
* <property name="accessModifiers" value="public"/>
* </module>
* </pre>
* <p>
* Java code example:
* </p>
* <pre>
* public record MyRecord1(int x, int y, String str) { // ok, public record definition allowed 10
* ...
* }
*
* private record MyRecord2(int x, int y, String str, Node node) { // violation
* ... // private record definition allowed 3 components
* }
* </pre>
* <p>
* Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
* </p>
* <p>
* Violation Message Keys:
* </p>
* <ul>
* <li>
* {@code too.many.components}
* </li>
* </ul>
*
* @since 8.36
*/
@StatelessCheck
public class RecordComponentNumberCheck extends AbstractCheck {
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_KEY = "too.many.components";
/** Default maximum number of allowed components. */
private static final int DEFAULT_MAX_COMPONENTS = 8;
/** Specify the maximum number of components allowed in the header of a record definition. */
private int max = DEFAULT_MAX_COMPONENTS;
/**
* Access modifiers of record definitions where the number
* of record components should be checked.
*/
private AccessModifierOption[] accessModifiers = {
AccessModifierOption.PUBLIC,
AccessModifierOption.PROTECTED,
AccessModifierOption.PACKAGE,
AccessModifierOption.PRIVATE,
};
/**
* Setter to specify the maximum number of components allowed in the header
* of a record definition.
*
* @param value the maximum allowed.
*/
public void setMax(int value) {
max = value;
}
/**
* Setter to access modifiers of record definitions where the number of record
* components should be checked.
*
* @param accessModifiers access modifiers of record definitions which should be checked.
*/
public void setAccessModifiers(AccessModifierOption... accessModifiers) {
this.accessModifiers =
Arrays.copyOf(accessModifiers, accessModifiers.length);
}
@Override
public int[] getDefaultTokens() {
return getAcceptableTokens();
}
@Override
public int[] getAcceptableTokens() {
return new int[] {
TokenTypes.RECORD_DEF,
};
}
@Override
public int[] getRequiredTokens() {
return getAcceptableTokens();
}
@Override
public void visitToken(DetailAST ast) {
final AccessModifierOption accessModifier =
CheckUtil.getAccessModifierFromModifiersToken(ast);
if (matchAccessModifiers(accessModifier)) {
final DetailAST recordComponents =
ast.findFirstToken(TokenTypes.RECORD_COMPONENTS);
final int componentCount = countComponents(recordComponents);
if (componentCount > max) {
log(ast, MSG_KEY, componentCount, max);
}
}
}
/**
* Method to count the number of record components in this record definition.
*
* @param recordComponents the ast to check
* @return the number of record components in this record definition
*/
private static int countComponents(DetailAST recordComponents) {
final AtomicInteger count = new AtomicInteger(0);
TokenUtil.forEachChild(recordComponents,
TokenTypes.RECORD_COMPONENT_DEF,
node -> count.getAndIncrement());
return count.get();
}
/**
* Checks whether a record definition has the correct access modifier to be checked.
*
* @param accessModifier the access modifier of the record definition.
* @return whether the record definition matches the expected access modifier.
*/
private boolean matchAccessModifiers(final AccessModifierOption accessModifier) {
return Arrays.stream(accessModifiers)
.anyMatch(modifier -> modifier == accessModifier);
}
}