Pull Request #1 (SQR course) | Add record validation checker

.github/workflows/mvn.yml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       matrix:
         os: [windows-2022, ubuntu-24.04, macos-15]
-        java: [11, 21]
+        java: [11, 17, 21]
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-java@v4

qulice-checkstyle/src/main/java/com/qulice/checkstyle/RecordValidationCheck.java

@@ -0,0 +1,120 @@
+/*
+ * SPDX-FileCopyrightText: Copyright (c) 2011-2025 Yegor Bugayenko
+ * SPDX-License-Identifier: MIT
+ */
+package com.qulice.checkstyle;
+
+import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
+import com.puppycrawl.tools.checkstyle.api.DetailAST;
+import com.puppycrawl.tools.checkstyle.api.TokenTypes;
+
+/**
+ * Checks for proper record declarations.
+ * Validates that:
+ * 1. Records are properly declared with components
+ * 2. Record components are properly formatted
+ * 3. Records do not extend other classes
+ * 4. Records are final
+ * @since 0.24
+ */
+public final class RecordValidationCheck extends AbstractCheck {
+    /**
+     * A key is pointing to the warning message text in "messages.properties"
+     * file.
+     */
+    public static final String MSG_KEY = "record.validation";
+
+    @Override
+    public int[] getDefaultTokens() {
+        return new int[] {
+            TokenTypes.RECORD_DEF,
+            TokenTypes.RECORD_COMPONENT_DEF,
+        };
+    }
+
+    @Override
+    public int[] getAcceptableTokens() {
+        return this.getDefaultTokens();
+    }
+
+    @Override
+    public int[] getRequiredTokens() {
+        return this.getDefaultTokens();
+    }
+
+    @Override
+    public void visitToken(final DetailAST ast) {
+        switch (ast.getType()) {
+            case TokenTypes.RECORD_DEF:
+                this.checkRecordDeclaration(ast);
+                break;
+            case TokenTypes.RECORD_COMPONENT_DEF:
+                this.checkRecordComponent(ast);
+                break;
+            default:
+        }
+    }
+
+    /**
+     * Check if record extends another class.
+     * Check if record is final.
+     * Check if record has components.
+     * @param ast EXPR RECORD_DEF node that needs to be checked
+     */
+    private void checkRecordDeclaration(final DetailAST ast) {
+        if (ast.findFirstToken(TokenTypes.EXTENDS_CLAUSE) != null) {
+            this.log(ast.getLineNo(), ast.getColumnNo(), "Records cannot extend other classes");
+        }
+        final DetailAST modifiers = ast.findFirstToken(TokenTypes.MODIFIERS);
+        if (modifiers != null && modifiers.findFirstToken(TokenTypes.FINAL) == null) {
+            this.log(modifiers.getLineNo(), modifiers.getColumnNo(), "Records must be final");
+        }
+        final DetailAST components = ast.findFirstToken(TokenTypes.RECORD_COMPONENTS);
+        if (components != null
+            && components.findFirstToken(TokenTypes.RECORD_COMPONENT_DEF) == null) {
+            this.log(
+                components.getLineNo(),
+                components.getColumnNo(),
+                "Records must declare at least one component"
+            );
+        }
+        this.checkRecordInstanceFields(ast);
+    }
+
+    /**
+     * Check record does not contain instance field.
+     * @param ast EXPR RECORD_DEF node that needs to be checked
+     */
+    private void checkRecordInstanceFields(final DetailAST ast) {
+        final DetailAST block = ast.findFirstToken(TokenTypes.OBJBLOCK);
+        DetailAST child = block.getFirstChild();
+        while (child != null) {
+            if (child.getType() == TokenTypes.VARIABLE_DEF) {
+                final DetailAST modifiers = child.findFirstToken(TokenTypes.MODIFIERS);
+                final DetailAST statics = modifiers.findFirstToken(TokenTypes.LITERAL_STATIC);
+                if (statics == null) {
+                    this.log(
+                        child.getLineNo(),
+                        child.getColumnNo(),
+                        "Records cannot have instance fields"
+                    );
+                }
+            }
+            child = child.getNextSibling();
+        }
+    }
+
+    /**
+     * Check if component has a type.
+     * Check if component has a name.
+     * @param ast EXPR RECORD_COMPONENT_DEF node that needs to be checked
+     */
+    private void checkRecordComponent(final DetailAST ast) {
+        if (ast.findFirstToken(TokenTypes.TYPE) == null) {
+            this.log(ast.getLineNo(), ast.getColumnNo(), "Record component must have a type");
+        }
+        if (ast.findFirstToken(TokenTypes.IDENT) == null) {
+            this.log(ast.getLineNo(), ast.getColumnNo(), "Record component must have a name");
+        }
+    }
+}

qulice-checkstyle/src/test/java/com/qulice/checkstyle/ChecksTest.java

@@ -151,6 +151,7 @@ private void check(
     @SuppressWarnings("PMD.UnusedPrivateMethod")
     private static Stream<String> checks() {
         return Stream.of(
+            "RecordValidationCheck",
             "MethodsOrderCheck",
             "MultilineJavadocTagsCheck",
             "StringLiteralsConcatenationCheck",

qulice-checkstyle/src/test/resources/com/qulice/checkstyle/ChecksTest/RecordValidationCheck/Invalid.java

@@ -0,0 +1,13 @@
+/*
+ * SPDX-FileCopyrightText: Copyright (c) 2011-2025 Yegor Bugayenko
+ * SPDX-License-Identifier: MIT
+ */
+package com.qulice.modern;
+
+/**
+ * Invalid record example.
+ */
+// Records must be final
+public record InvalidRecord() { // Records must declare at least one component
+    private String extraField;  // Records cannot have instance fields
+}

qulice-checkstyle/src/test/resources/com/qulice/checkstyle/ChecksTest/RecordValidationCheck/Valid.java

@@ -0,0 +1,26 @@
+/*
+ * SPDX-FileCopyrightText: Copyright (c) 2011-2025 Yegor Bugayenko
+ * SPDX-License-Identifier: MIT
+ */
+package com.qulice.modern;
+
+/**
+ * Valid record example.
+ *
+ * @since 1.0
+ */
+public final record ValidRecord(String name, int age) {
+    /**
+     * Constructor.
+     * @param name Name
+     * @param age Age
+     */
+    public ValidRecord {
+        if (name == null || name.isEmpty()) {
+            throw new IllegalArgumentException("Name cannot be empty");
+        }
+        if (age < 0) {
+            throw new IllegalArgumentException("Age cannot be negative");
+        }
+    }
+} 

qulice-checkstyle/src/test/resources/com/qulice/checkstyle/ChecksTest/RecordValidationCheck/config.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0"?>
+<!--
+ * SPDX-FileCopyrightText: Copyright (c) 2011-2025 Yegor Bugayenko
+ * SPDX-License-Identifier: MIT
+-->
+<!DOCTYPE module PUBLIC
+    "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+    "https://checkstyle.org/dtds/configuration_1_3.dtd">
+<module name="Checker">
+    <module name="TreeWalker">
+        <module name="com.qulice.checkstyle.RecordValidationCheck"/>
+    </module>
+</module>

qulice-checkstyle/src/test/resources/com/qulice/checkstyle/ChecksTest/RecordValidationCheck/violations.txt

@@ -0,0 +1,3 @@
+11:Records must be final
+11:Records must declare at least one component
+12:Records cannot have instance fields