added StringConstantExpressionTest

src/test/java/StringConstantExpressionTest.java

@@ -0,0 +1,37 @@
+import org.jd.core.v1.model.javasyntax.expression.StringConstantExpression;
+import org.jd.core.v1.model.javasyntax.type.ObjectType;
+import org.jd.core.v1.service.converter.classfiletojavasyntax.visitor.TestVisitor;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class StringConstantExpressionTest {
+
+    @Test
+    public void testStringConstantExpression() {
+        // Arrange
+        int lineNumber = 10;
+        String string = "Hello, World!";
+        TestVisitor visitor = new TestVisitor();
+
+        // Act
+        StringConstantExpression expression = new StringConstantExpression(lineNumber, string);
+        expression.accept(visitor);
+
+        // Assert
+        Assert.assertEquals(lineNumber, expression.getLineNumber());
+        Assert.assertEquals(string, expression.getStringValue());
+        Assert.assertEquals(ObjectType.TYPE_STRING, expression.getType());
+        Assert.assertTrue(expression.isStringConstantExpression());
+        Assert.assertEquals(1, visitor.getStringConstantExpressionCount());
+
+        // Test toString method
+        String expectedToString = "StringConstantExpression{\"Hello, World!\"}";
+        Assert.assertEquals(expectedToString, expression.toString());
+
+        // Test copyTo method
+        int newLineNumber = 20;
+        StringConstantExpression copiedExpression = (StringConstantExpression) expression.copyTo(newLineNumber);
+        Assert.assertEquals(newLineNumber, copiedExpression.getLineNumber());
+        Assert.assertEquals(string, copiedExpression.getStringValue());
+    }
+}