diff --git a/liquidjava-verifier/pom.xml b/liquidjava-verifier/pom.xml
index 5b42f4cb..b6262a97 100644
--- a/liquidjava-verifier/pom.xml
+++ b/liquidjava-verifier/pom.xml
@@ -19,6 +19,45 @@
 	<build>
 		<finalName>${jar.finalName}</finalName>
 		<plugins>
+			<plugin>
+				<groupId>org.jacoco</groupId>
+				<artifactId>jacoco-maven-plugin</artifactId>
+				<version>0.8.14</version>
+				<executions>
+				<execution>
+				<id>default-prepare-agent</id>
+				<goals>
+				<goal>prepare-agent</goal>
+				</goals>
+				</execution>
+				<execution>
+				<id>default-report</id>
+				<goals>
+				<goal>report</goal>
+				</goals>
+				</execution>
+				<execution>
+				<id>default-check</id>
+				<goals>
+				<goal>check</goal>
+				</goals>
+				<configuration>
+				<rules>
+				<rule>
+				<element>BUNDLE</element>
+				<limits>
+				<limit>
+				<counter>COMPLEXITY</counter>
+				<value>COVEREDRATIO</value>
+				<minimum>0.60</minimum>
+				</limit>
+				</limits>
+				</rule>
+				</rules>
+				</configuration>
+				</execution>
+				</executions>
+			</plugin>
 			<plugin>
 				<groupId>net.revelc.code.formatter</groupId>
 				<artifactId>formatter-maven-plugin</artifactId>
@@ -98,6 +137,8 @@
 		</plugins>
 	</build>
 
+
+
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<maven.compiler.source>20</maven.compiler.source>
diff --git a/liquidjava-verifier/src/test/java/liquidjava/rj_language/TestLiteralString.java b/liquidjava-verifier/src/test/java/liquidjava/rj_language/TestLiteralString.java
new file mode 100644
index 00000000..dcf776ad
--- /dev/null
+++ b/liquidjava-verifier/src/test/java/liquidjava/rj_language/TestLiteralString.java
@@ -0,0 +1,25 @@
+package liquidjava.rj_language;
+
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.assertFalse;
+import org.junit.Test;
+import liquidjava.rj_language.ast.LiteralString;
+
+public class TestLiteralString {
+    @Test
+    public void testLiteralString() {
+        LiteralString s1 = new LiteralString("hello");
+        LiteralString s2 = new LiteralString("world");
+        assertNotEquals(s1.hashCode(), s2.hashCode());
+    }
+
+    @Test
+    public void testLiteralStringEquals() {
+        LiteralString s1 = new LiteralString("hello");
+        LiteralString s2 = new LiteralString("world");
+        LiteralString s3 = new LiteralString("hello");
+        assertTrue(s1.equals(s3));
+        assertFalse(s1.equals(s2));
+    }
+}
diff --git a/liquidjava-verifier/src/test/java/liquidjava/rj_language/opt/TestOptimization.java b/liquidjava-verifier/src/test/java/liquidjava/rj_language/opt/TestOptimization.java
new file mode 100644
index 00000000..cdf819a8
--- /dev/null
+++ b/liquidjava-verifier/src/test/java/liquidjava/rj_language/opt/TestOptimization.java
@@ -0,0 +1,18 @@
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+import liquidjava.rj_language.ast.BinaryExpression;
+import liquidjava.rj_language.ast.LiteralInt;
+import liquidjava.rj_language.opt.ConstantFolding;
+import liquidjava.rj_language.opt.derivation_node.ValDerivationNode;
+
+public class TestOptimization {
+    @Test
+    public void testBinaryFold() {
+        BinaryExpression b = new BinaryExpression(new LiteralInt(1), "+", new LiteralInt(2));
+
+        ValDerivationNode r = ConstantFolding.fold(new ValDerivationNode(b, null));
+        assertEquals(r.getValue(), new LiteralInt(3));
+    }
+}