Add comprehensive unit tests for CSS parser core classes

src/test/java/org/htmlunit/cssparser/dom/AbstractCSSRuleImplTest.java

@@ -0,0 +1,202 @@
+/*
+ * Copyright (c) 2019-2024 Ronald Brill.
+ *
+ * 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
+ * https://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.htmlunit.cssparser.dom;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * Unit tests for {@link AbstractCSSRuleImpl}.
+ *
+ * @author Ronald Brill
+ */
+public class AbstractCSSRuleImplTest {
+
+    /**
+     * Test parent style sheet getter/setter.
+     * @throws Exception if any error occurs
+     */
+    @Test
+    public void parentStyleSheet() throws Exception {
+        final CSSStyleSheetImpl styleSheet = new CSSStyleSheetImpl();
+        final CSSStyleRuleImpl rule = new CSSStyleRuleImpl(styleSheet, null, null);
+
+        assertEquals(styleSheet, rule.getParentStyleSheet());
+
+        final CSSStyleSheetImpl newStyleSheet = new CSSStyleSheetImpl();
+        rule.setParentStyleSheet(newStyleSheet);
+
+        assertEquals(newStyleSheet, rule.getParentStyleSheet());
+    }
+
+    /**
+     * Test parent rule getter/setter.
+     * @throws Exception if any error occurs
+     */
+    @Test
+    public void parentRule() throws Exception {
+        final CSSStyleSheetImpl styleSheet = new CSSStyleSheetImpl();
+        final CSSPageRuleImpl parentRule = new CSSPageRuleImpl(styleSheet, null, null);
+        final CSSStyleRuleImpl rule = new CSSStyleRuleImpl(styleSheet, parentRule, null);
+
+        assertEquals(parentRule, rule.getParentRule());
+
+        final CSSPageRuleImpl newParentRule = new CSSPageRuleImpl(styleSheet, null, null);
+        rule.setParentRule(newParentRule);
+
+        assertEquals(newParentRule, rule.getParentRule());
+    }
+
+    /**
+     * Test with null parent style sheet.
+     * @throws Exception if any error occurs
+     */
+    @Test
+    public void nullParentStyleSheet() throws Exception {
+        final CSSStyleRuleImpl rule = new CSSStyleRuleImpl(null, null, null);
+
+        assertNull(rule.getParentStyleSheet());
+    }
+
+    /**
+     * Test with null parent rule.
+     * @throws Exception if any error occurs
+     */
+    @Test
+    public void nullParentRule() throws Exception {
+        final CSSStyleSheetImpl styleSheet = new CSSStyleSheetImpl();
+        final CSSStyleRuleImpl rule = new CSSStyleRuleImpl(styleSheet, null, null);
+
+        assertNull(rule.getParentRule());
+    }
+
+    /**
+     * Test equals with same object.
+     * @throws Exception if any error occurs
+     */
+    @Test
+    public void equalsSameObject() throws Exception {
+        final CSSStyleSheetImpl styleSheet = new CSSStyleSheetImpl();
+        final CSSStyleRuleImpl rule = new CSSStyleRuleImpl(styleSheet, null, null);
+
+        assertTrue(rule.equals(rule));
+    }
+
+    /**
+     * Test equals with different types.
+     * @throws Exception if any error occurs
+     */
+    @Test
+    public void equalsDifferentType() throws Exception {
+        final CSSStyleSheetImpl styleSheet = new CSSStyleSheetImpl();
+        final CSSStyleRuleImpl rule = new CSSStyleRuleImpl(styleSheet, null, null);
+
+        assertFalse(rule.equals("not a rule"));
+        assertFalse(rule.equals(null));
+    }
+
+    /**
+     * Test that parent relationships don't cause stack overflow in equals.
+     * @throws Exception if any error occurs
+     */
+    @Test
+    public void equalsNoStackOverflow() throws Exception {
+        final CSSStyleSheetImpl styleSheet = new CSSStyleSheetImpl();
+        final CSSPageRuleImpl parent1 = new CSSPageRuleImpl(styleSheet, null, null);
+        final CSSStyleRuleImpl rule1 = new CSSStyleRuleImpl(styleSheet, parent1, null);
+
+        final CSSPageRuleImpl parent2 = new CSSPageRuleImpl(styleSheet, null, null);
+        final CSSStyleRuleImpl rule2 = new CSSStyleRuleImpl(styleSheet, parent2, null);
+
+        // This should not cause stack overflow even with parent relationships
+        rule1.equals(rule2);
+    }
+
+    /**
+     * Test hashCode consistency.
+     * @throws Exception if any error occurs
+     */
+    @Test
+    public void hashCodeConsistency() throws Exception {
+        final CSSStyleSheetImpl styleSheet = new CSSStyleSheetImpl();
+        final CSSStyleRuleImpl rule = new CSSStyleRuleImpl(styleSheet, null, null);
+
+        final int hash1 = rule.hashCode();
+        final int hash2 = rule.hashCode();
+
+        assertEquals(hash1, hash2);
+    }
+
+    /**
+     * Test that parent relationships don't cause stack overflow in hashCode.
+     * @throws Exception if any error occurs
+     */
+    @Test
+    public void hashCodeNoStackOverflow() throws Exception {
+        final CSSStyleSheetImpl styleSheet = new CSSStyleSheetImpl();
+        final CSSPageRuleImpl parent = new CSSPageRuleImpl(styleSheet, null, null);
+        final CSSStyleRuleImpl rule = new CSSStyleRuleImpl(styleSheet, parent, null);
+
+        // This should not cause stack overflow
+        final int hash = rule.hashCode();
+        assertNotEquals(0, hash); // Just verify it computed something
+    }
+
+    /**
+     * Test changing parent style sheet after construction.
+     * @throws Exception if any error occurs
+     */
+    @Test
+    public void changeParentStyleSheet() throws Exception {
+        final CSSStyleSheetImpl styleSheet1 = new CSSStyleSheetImpl();
+        final CSSStyleRuleImpl rule = new CSSStyleRuleImpl(styleSheet1, null, null);
+
+        assertEquals(styleSheet1, rule.getParentStyleSheet());
+
+        final CSSStyleSheetImpl styleSheet2 = new CSSStyleSheetImpl();
+        rule.setParentStyleSheet(styleSheet2);
+
+        assertEquals(styleSheet2, rule.getParentStyleSheet());
+
+        rule.setParentStyleSheet(null);
+        assertNull(rule.getParentStyleSheet());
+    }
+
+    /**
+     * Test changing parent rule after construction.
+     * @throws Exception if any error occurs
+     */
+    @Test
+    public void changeParentRule() throws Exception {
+        final CSSStyleSheetImpl styleSheet = new CSSStyleSheetImpl();
+        final CSSPageRuleImpl parent1 = new CSSPageRuleImpl(styleSheet, null, null);
+        final CSSStyleRuleImpl rule = new CSSStyleRuleImpl(styleSheet, parent1, null);
+
+        assertEquals(parent1, rule.getParentRule());
+
+        final CSSPageRuleImpl parent2 = new CSSPageRuleImpl(styleSheet, null, null);
+        rule.setParentRule(parent2);
+
+        assertEquals(parent2, rule.getParentRule());
+
+        rule.setParentRule(null);
+        assertNull(rule.getParentRule());
+    }
+}

src/test/java/org/htmlunit/cssparser/dom/PropteryTest.java

@@ -94,4 +94,83 @@ public void constructWithParams() throws Exception {
         assertEquals("13.2cm", prop.getValue().toString());
         assertFalse(prop.isImportant());
     }
+
+    /**
+     * Test equals method with same object.
+     * @throws Exception if any error occurs
+     */
+    @Test
+    public void equalsSameObject() throws Exception {
+        final LexicalUnit lu = LexicalUnitImpl.createPixel(null, 10);
+        final Property prop = new Property("color", new CSSValueImpl(lu, true), false);
+
+        assertTrue(prop.equals(prop));
+    }
+
+    /**
+     * Test equals method with different names.
+     * @throws Exception if any error occurs
+     */
+    @Test
+    public void equalsDifferentNames() throws Exception {
+        final LexicalUnit lu1 = LexicalUnitImpl.createPixel(null, 10);
+        final Property prop1 = new Property("color", new CSSValueImpl(lu1, true), false);
+
+        final LexicalUnit lu2 = LexicalUnitImpl.createPixel(null, 10);
+        final Property prop2 = new Property("background", new CSSValueImpl(lu2, true), false);
+
+        assertFalse(prop1.equals(prop2));
+    }
+
+    /**
+     * Test equals method with different important flags.
+     * @throws Exception if any error occurs
+     */
+    @Test
+    public void equalsDifferentImportant() throws Exception {
+        final Property prop1 = new Property("color", null, false);
+        final Property prop2 = new Property("color", null, true);
+
+        assertFalse(prop1.equals(prop2));
+    }
+
+    /**
+     * Test equals method with null.
+     * @throws Exception if any error occurs
+     */
+    @Test
+    public void equalsWithNull() throws Exception {
+        final LexicalUnit lu = LexicalUnitImpl.createPixel(null, 10);
+        final Property prop = new Property("color", new CSSValueImpl(lu, true), false);
+
+        assertFalse(prop.equals(null));
+    }
+
+    /**
+     * Test equals method with different class.
+     * @throws Exception if any error occurs
+     */
+    @Test
+    public void equalsWithDifferentClass() throws Exception {
+        final LexicalUnit lu = LexicalUnitImpl.createPixel(null, 10);
+        final Property prop = new Property("color", new CSSValueImpl(lu, true), false);
+
+        assertFalse(prop.equals("not a property"));
+    }
+
+    /**
+     * Test hashCode consistency.
+     * @throws Exception if any error occurs
+     */
+    @Test
+    public void hashCodeConsistency() throws Exception {
+        final LexicalUnit lu = LexicalUnitImpl.createPixel(null, 10);
+        final Property prop = new Property("color", new CSSValueImpl(lu, true), false);
+
+        final int hash1 = prop.hashCode();
+        final int hash2 = prop.hashCode();
+
+        assertEquals(hash1, hash2);
+    }
 }
+