fix: Fix equality for CtCodeSnippet (#4024)

src/main/java/spoon/support/visitor/equals/EqualsChecker.java

@@ -16,6 +16,7 @@
 import spoon.reflect.code.CtStatement;
 import spoon.reflect.code.CtTextBlock;
 import spoon.reflect.code.CtUnaryOperator;
+import spoon.reflect.declaration.CtCodeSnippet;
 import spoon.reflect.declaration.CtElement;
 import spoon.reflect.declaration.CtMethod;
 import spoon.reflect.declaration.CtModifiable;
@@ -109,6 +110,15 @@ public void scanCtModifiable(CtModifiable m) {
 		super.scanCtModifiable(m);
 	}
 
+	@Override
+	public void scanCtCodeSnippet(CtCodeSnippet snippet) {
+		final CtCodeSnippet peek = (CtCodeSnippet) this.other;
+		if (!snippet.getValue().equals(peek.getValue())) {
+			setNotEqual(CtRole.SNIPPET);
+		}
+		super.scanCtCodeSnippet(snippet);
+	}
+
 	@Override
 	public <T, A extends T> void visitCtAssignment(CtAssignment<T, A> assignment) {
 		if (!(assignment instanceof CtOperatorAssignment) && this.other instanceof CtOperatorAssignment) {

src/test/java/spoon/test/snippets/SnippetTest.java

@@ -38,6 +38,8 @@
 import spoon.support.compiler.SnippetCompilationHelper;
 import spoon.support.compiler.VirtualFile;
 
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertSame;
@@ -239,4 +241,50 @@ public void testSnippetCompilationInUnnamedPackage() {
 		assertTrue(body.getStatements().get(0) instanceof CtLocalVariable);
 		assertEquals(1,body.getStatements().size()); 
 	}
+
+	@Test
+	public void testCodeSnippetExpressionsWithNonEqualValuesAreNotEqual() {
+		// contract: Two code snippet expressions with non-equal values are not equal
+		Factory factory = new Launcher().getFactory();
+
+		CtCodeSnippetExpression<Integer> one = factory.createCodeSnippetExpression("1");
+		CtCodeSnippetExpression<Integer> two = factory.createCodeSnippetExpression("2");
+
+		assertThat(one.equals(two), is(false));
+	}
+
+	@Test
+	public void testCodeSnippetExpressionsWithEqualValuesAreEqual() {
+		// contract: Two code snippet expressions with equal values, that are also otherwise equal,
+		// are equal
+		Factory factory = new Launcher().getFactory();
+
+		CtCodeSnippetExpression<Integer> one = factory.createCodeSnippetExpression("1");
+		CtCodeSnippetExpression<Integer> alsoOne = factory.createCodeSnippetExpression("1");
+
+		assertThat(one.equals(alsoOne), is(true));
+	}
+
+	@Test
+	public void testCodeSnippetStatementsWithNonEqualValuesAreNotEqual() {
+		// contract: Two code snippet statements with non-equal values are not equal
+		Factory factory = new Launcher().getFactory();
+
+		CtCodeSnippetStatement intDeclaration = factory.createCodeSnippetStatement("int a;");
+		CtCodeSnippetStatement doubleDeclaration = factory.createCodeSnippetStatement("double a;");
+
+		assertThat(intDeclaration.equals(doubleDeclaration), is(false));
+	}
+
+	@Test
+	public void testCodeSnippetStatementsWithEqualValuesAreEqual() {
+		// contract: Two code snippet statements with equal values, that are also otherwise equal,
+		// are equal
+		Factory factory = new Launcher().getFactory();
+
+		CtCodeSnippetStatement intDeclaration = factory.createCodeSnippetStatement("int a;");
+		CtCodeSnippetStatement alsoIntDeclaration = factory.createCodeSnippetStatement("int a;");
+
+		assertThat(intDeclaration.equals(alsoIntDeclaration), is(true));
+	}
 }