Issue checkstyle#6847: Add UnnecessarySemicolonAfterTypeMemberDeclara…

…tionCheck

.ci/jsoref-spellchecker/whitelist.words

@@ -1293,6 +1293,7 @@ uniqueproperties
 Unitless
 unlzma
 unnecessaryparentheses
+unnecessarysemicolonaftertypememberdeclaration
 unnecessarysemicoloninenumeration
 unnecessarysemicolonintrywithresources
 Unproxyable

config/checkstyle_checks.xml

@@ -361,6 +361,7 @@
     <module name="SuperClone"/>
     <module name="SuperFinalize"/>
     <module name="UnnecessaryParentheses"/>
+    <module name="UnnecessarySemicolonAfterTypeMemberDeclaration"/>
     <module name="UnnecessarySemicolonInEnumeration"/>
     <module name="UnnecessarySemicolonInTryWithResources"/>
     <module name="VariableDeclarationUsageDistance"/>

src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionUnnecessarySemicolonAfterTypeMemberDeclarationTest.java

@@ -0,0 +1,59 @@
+////////////////////////////////////////////////////////////////////////////////
+// checkstyle: Checks Java source code for adherence to a set of rules.
+// Copyright (C) 2001-2019 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 org.checkstyle.suppressionxpathfilter;
+
+import java.io.File;
+import java.util.Collections;
+import java.util.List;
+
+import org.junit.Test;
+
+import com.puppycrawl.tools.checkstyle.DefaultConfiguration;
+import com.puppycrawl.tools.checkstyle.checks.coding.UnnecessarySemicolonAfterTypeMemberDeclarationCheck;
+
+public class XpathRegressionUnnecessarySemicolonAfterTypeMemberDeclarationTest
+        extends AbstractXpathTestSupport {
+
+    private static final Class<UnnecessarySemicolonAfterTypeMemberDeclarationCheck> CLASS =
+        UnnecessarySemicolonAfterTypeMemberDeclarationCheck.class;
+
+    @Override
+    protected String getCheckName() {
+        return CLASS.getSimpleName();
+    }
+
+    @Test
+    public void testOne() throws Exception {
+        final File fileToProcess = new File(getPath(
+            "SuppressionXpathRegressionUnnecessarySemicolonAfterTypeMemberDeclaration.java"));
+        final DefaultConfiguration moduleConfig = createModuleConfig(CLASS);
+        final String[] expectedViolation = {
+            "4:20: " + getCheckMessage(CLASS,
+                UnnecessarySemicolonAfterTypeMemberDeclarationCheck.MSG_SEMI),
+        };
+
+        final List<String> expectedXpathQueries = Collections.singletonList("/CLASS_DEF[./IDENT"
+            + "[@text='SuppressionXpathRegressionUnnecessarySemicolonAfterTypeMemberDeclaration']]"
+            + "/OBJBLOCK/SEMI"
+        );
+
+        runVerifications(moduleConfig, fileToProcess, expectedViolation, expectedXpathQueries);
+    }
+}

src/it/resources/org/checkstyle/suppressionxpathfilter/unnecessarysemicolonaftertypememberdeclaration/SuppressionXpathRegressionUnnecessarySemicolonAfterTypeMemberDeclaration.java

@@ -0,0 +1,5 @@
+package org.checkstyle.suppressionxpathfilter.unnecessarysemicolonaftertypememberdeclaration;
+
+public class SuppressionXpathRegressionUnnecessarySemicolonAfterTypeMemberDeclaration {
+    void method(){}; //warn
+}

src/main/java/com/puppycrawl/tools/checkstyle/PackageObjectFactory.java

@@ -537,6 +537,9 @@ private static void fillChecksFromCodingPackage() {
                 BASE_PACKAGE + ".checks.coding.SuperFinalizeCheck");
         NAME_TO_FULL_MODULE_NAME.put("UnnecessaryParenthesesCheck",
                 BASE_PACKAGE + ".checks.coding.UnnecessaryParenthesesCheck");
+        NAME_TO_FULL_MODULE_NAME.put("UnnecessarySemicolonAfterTypeMemberDeclarationCheck",
+                BASE_PACKAGE
+                    + ".checks.coding.UnnecessarySemicolonAfterTypeMemberDeclarationCheck");
         NAME_TO_FULL_MODULE_NAME.put("UnnecessarySemicolonInEnumerationCheck",
                 BASE_PACKAGE + ".checks.coding.UnnecessarySemicolonInEnumerationCheck");
         NAME_TO_FULL_MODULE_NAME.put("UnnecessarySemicolonInTryWithResourcesCheck",

src/main/java/com/puppycrawl/tools/checkstyle/checks/coding/UnnecessarySemicolonAfterTypeMemberDeclarationCheck.java

@@ -0,0 +1,177 @@
+////////////////////////////////////////////////////////////////////////////////
+// checkstyle: Checks Java source code for adherence to a set of rules.
+// Copyright (C) 2001-2019 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.coding;
+
+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.utils.ScopeUtil;
+
+/**
+ * <p>
+ * Checks if unnecessary semicolon is used after code type member declaration.
+ * The check will flag the following with warnings:
+ * </p>
+ * <pre>
+ * class A {
+ *     ; // standalone semicolon
+ *     {}; // semicolon after init block
+ *     static {}; // semicolon after static init block
+ *     A(){}; // semicolon after constructor definition
+ *     void method() {}; // semicolon after method definition
+ *     int field = 10;; // semicolon after field declaration
+ * }
+ * </pre>
+ * <p>
+ * To configure the check:
+ * </p>
+ * <pre>
+ * &lt;module name=&quot;UnnecessarySemicolonAfterTypeMemberDeclaration&quot;/&gt;
+ * </pre>
+ *
+ * @since 8.23
+ */
+@StatelessCheck
+public final class UnnecessarySemicolonAfterTypeMemberDeclarationCheck extends AbstractCheck {
+
+    /**
+     * A key is pointing to the warning message text in "messages.properties"
+     * file.
+     */
+    public static final String MSG_SEMI = "unnecessary.semicolon";
+
+    @Override
+    public int[] getDefaultTokens() {
+        return getRequiredTokens();
+    }
+
+    @Override
+    public int[] getAcceptableTokens() {
+        return getRequiredTokens();
+    }
+
+    @Override
+    public int[] getRequiredTokens() {
+        return new int[] {
+            TokenTypes.CLASS_DEF,
+            TokenTypes.INTERFACE_DEF,
+            TokenTypes.ENUM_DEF,
+            TokenTypes.ANNOTATION_DEF,
+            TokenTypes.VARIABLE_DEF,
+            TokenTypes.STATIC_INIT,
+            TokenTypes.INSTANCE_INIT,
+            TokenTypes.CTOR_DEF,
+            TokenTypes.METHOD_DEF,
+            TokenTypes.ENUM_CONSTANT_DEF,
+        };
+    }
+
+    @Override
+    public void visitToken(DetailAST ast) {
+        switch (ast.getType()) {
+            case TokenTypes.CLASS_DEF:
+            case TokenTypes.INTERFACE_DEF:
+            case TokenTypes.ENUM_DEF:
+            case TokenTypes.ANNOTATION_DEF:
+                checkTypeDefinition(ast);
+                break;
+            case TokenTypes.VARIABLE_DEF:
+                checkVariableDefinition(ast);
+                break;
+            case TokenTypes.ENUM_CONSTANT_DEF:
+                checkEnumConstant(ast);
+                break;
+            default:
+                checkTypeMember(ast);
+                break;
+        }
+    }
+
+    /**
+     * Checks if type member has unnecessary semicolon.
+     *
+     * @param ast type member
+     */
+    private void checkTypeMember(DetailAST ast) {
+        if (isSemicolon(ast.getNextSibling())) {
+            log(ast.getNextSibling(), MSG_SEMI);
+        }
+    }
+
+    /**
+     * Checks if type definition has unnecessary semicolon.
+     *
+     * @param ast type definition
+     */
+    private void checkTypeDefinition(DetailAST ast) {
+        if (!ScopeUtil.isOuterMostType(ast) && isSemicolon(ast.getNextSibling())) {
+            log(ast.getNextSibling(), MSG_SEMI);
+        }
+        final DetailAST firstMember =
+            ast.findFirstToken(TokenTypes.OBJBLOCK).getFirstChild().getNextSibling();
+        if (isSemicolon(firstMember) && !ScopeUtil.isInEnumBlock(firstMember)) {
+            log(firstMember, MSG_SEMI);
+        }
+    }
+
+    /**
+     * Checks if variable definition has unnecessary semicolon.
+     *
+     * @param ast variable definition
+     */
+    private void checkVariableDefinition(DetailAST ast) {
+        if (isFieldDeclaration(ast) && isSemicolon(ast.getNextSibling())) {
+            log(ast.getNextSibling(), MSG_SEMI);
+        }
+    }
+
+    /**
+     * Checks if enum constant has unnecessary semicolon.
+     *
+     * @param ast enum constant
+     */
+    private void checkEnumConstant(DetailAST ast) {
+        final DetailAST next = ast.getNextSibling();
+        if (isSemicolon(next) && isSemicolon(next.getNextSibling())) {
+            log(next.getNextSibling(), MSG_SEMI);
+        }
+    }
+
+    /**
+     * Checks that {@code ast} is a semicolon.
+     *
+     * @param ast token to check
+     * @return true if ast is semicolon, false otherwise
+     */
+    private static boolean isSemicolon(DetailAST ast) {
+        return ast.getType() == TokenTypes.SEMI;
+    }
+
+    /**
+     * Checks that {@code variableDef} is a field declaration.
+     *
+     * @param variableDef token to check
+     * @return true if variableDef is a field declaration, false otherwise
+     */
+    private static boolean isFieldDeclaration(DetailAST variableDef) {
+        return isSemicolon(variableDef.getLastChild());
+    }
+}

src/test/java/com/puppycrawl/tools/checkstyle/checks/coding/UnnecessarySemicolonAfterTypeMemberDeclarationCheckTest.java

@@ -0,0 +1,88 @@
+////////////////////////////////////////////////////////////////////////////////
+// checkstyle: Checks Java source code for adherence to a set of rules.
+// Copyright (C) 2001-2019 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.coding;
+
+import static com.puppycrawl.tools.checkstyle.checks.coding.UnnecessarySemicolonAfterTypeMemberDeclarationCheck.MSG_SEMI;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.puppycrawl.tools.checkstyle.AbstractModuleTestSupport;
+import com.puppycrawl.tools.checkstyle.DefaultConfiguration;
+import com.puppycrawl.tools.checkstyle.api.TokenTypes;
+
+public class UnnecessarySemicolonAfterTypeMemberDeclarationCheckTest
+    extends AbstractModuleTestSupport {
+
+    @Override
+    protected String getPackageLocation() {
+        return "com/puppycrawl/tools/checkstyle/checks/coding/"
+            + "unnecessarysemicolonaftertypememberdeclaration";
+    }
+
+    @Test
+    public void testDefault() throws Exception {
+        final DefaultConfiguration checkConfig =
+            createModuleConfig(UnnecessarySemicolonAfterTypeMemberDeclarationCheck.class);
+
+        final String[] expected = {
+            "7:5: " + getCheckMessage(MSG_SEMI),
+            "9:21: " + getCheckMessage(MSG_SEMI),
+            "11:14: " + getCheckMessage(MSG_SEMI),
+            "13:60: " + getCheckMessage(MSG_SEMI),
+            "15:14: " + getCheckMessage(MSG_SEMI),
+            "17:20: " + getCheckMessage(MSG_SEMI),
+            "19:19: " + getCheckMessage(MSG_SEMI),
+            "21:15: " + getCheckMessage(MSG_SEMI),
+            "23:23: " + getCheckMessage(MSG_SEMI),
+            "25:15: " + getCheckMessage(MSG_SEMI),
+            "28:13: " + getCheckMessage(MSG_SEMI),
+            "40:5: " + getCheckMessage(MSG_SEMI),
+            "43:5: " + getCheckMessage(MSG_SEMI),
+        };
+
+        verify(checkConfig, getPath("InputUnnecessarySemicolonAfterTypeMemberDeclaration.java"),
+            expected);
+    }
+
+    @Test
+    public void testTokens() {
+        final UnnecessarySemicolonAfterTypeMemberDeclarationCheck check =
+            new UnnecessarySemicolonAfterTypeMemberDeclarationCheck();
+        final int[] expected = {
+            TokenTypes.CLASS_DEF,
+            TokenTypes.INTERFACE_DEF,
+            TokenTypes.ENUM_DEF,
+            TokenTypes.ANNOTATION_DEF,
+            TokenTypes.VARIABLE_DEF,
+            TokenTypes.STATIC_INIT,
+            TokenTypes.INSTANCE_INIT,
+            TokenTypes.CTOR_DEF,
+            TokenTypes.METHOD_DEF,
+            TokenTypes.ENUM_CONSTANT_DEF,
+        };
+        Assert.assertArrayEquals("Acceptable required tokens are invalid",
+            expected, check.getAcceptableTokens());
+        Assert.assertArrayEquals("Default required tokens are invalid",
+            expected, check.getDefaultTokens());
+        Assert.assertArrayEquals("Required required tokens are invalid",
+            expected, check.getRequiredTokens());
+    }
+}