diff --git a/liquidjava-verifier/pom.xml b/liquidjava-verifier/pom.xml
index 5b42f4cb..07f589ec 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>0.40</minimum>
+										</limit>
+									</limits>
+								</rule>
+							</rules>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
 			<plugin>
 				<groupId>net.revelc.code.formatter</groupId>
 				<artifactId>formatter-maven-plugin</artifactId>
@@ -77,7 +116,8 @@
 						</goals>
 						<configuration>
 							<transformers>
-								<transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
+								<transformer
+									implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
 									<mainClass>liquidjava.api.CommandLineLauncher</mainClass>
 								</transformer>
 							</transformers>
@@ -206,4 +246,5 @@
 			</dependency>
 		</dependencies>
 	</dependencyManagement>
-</project>
+
+</project>
\ No newline at end of file
diff --git a/liquidjava-verifier/src/test/java/liquidjava/ast/opt/TestOptimization.java b/liquidjava-verifier/src/test/java/liquidjava/ast/opt/TestOptimization.java
new file mode 100644
index 00000000..85e99d31
--- /dev/null
+++ b/liquidjava-verifier/src/test/java/liquidjava/ast/opt/TestOptimization.java
@@ -0,0 +1,16 @@
+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;
+import static org.junit.Assert.assertEquals;
+import org.junit.Test;
+
+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));
+    }
+}
\ No newline at end of file
diff --git a/liquidjava-verifier/src/test/java/liquidjava/diagnostics/errors/LJErrorTest.java b/liquidjava-verifier/src/test/java/liquidjava/diagnostics/errors/LJErrorTest.java
new file mode 100644
index 00000000..38731578
--- /dev/null
+++ b/liquidjava-verifier/src/test/java/liquidjava/diagnostics/errors/LJErrorTest.java
@@ -0,0 +1,35 @@
+package liquidjava.diagnostics.errors;
+
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.Test;
+import spoon.reflect.declaration.CtElement;
+
+public class LJErrorTest {
+
+    static class ConcreteLJError extends LJError {
+        ConcreteLJError(String message, String details, CtElement element) {
+            super(message, details, element);
+        }
+
+        @Override
+        public String toString() {
+            return "ConcreteLJError: " + super.getMessage() + " | " + "Details field tested";
+        }
+    }
+
+    @Test
+    void testLJErrorMessage() {
+        LJError error = new ConcreteLJError("Test error message", "Details", null);
+        assertEquals("Details", error.getMessage());
+    }
+
+    @Test
+    void testToStringContainsMessage() {
+        LJError error = new ConcreteLJError("Invalid syntax", "Details", null);
+        String s = error.toString();
+
+        assertTrue(s.contains("ConcreteLJError"));
+        assertTrue(s.contains("Details"));
+    }
+
+}
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..bb198e05
--- /dev/null
+++ b/liquidjava-verifier/src/test/java/liquidjava/rj_language/TestLiteralString.java
@@ -0,0 +1,14 @@
+package liquidjava.rj_language;
+
+import static org.junit.Assert.assertNotEquals;
+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());
+    }
+}
\ No newline at end of file
diff --git a/liquidjava-verifier/src/test/java/rj/grammar/RJParserIntegrationTest.java b/liquidjava-verifier/src/test/java/rj/grammar/RJParserIntegrationTest.java
new file mode 100644
index 00000000..61e8b5a3
--- /dev/null
+++ b/liquidjava-verifier/src/test/java/rj/grammar/RJParserIntegrationTest.java
@@ -0,0 +1,28 @@
+package rj.grammar;
+
+import org.antlr.v4.runtime.*;
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.Test;
+
+public class RJParserIntegrationTest {
+
+    @Test
+    void testFullProgramParsing() {
+        String input = """
+                type MyAlias(int x) {
+                    !(x < 5)
+                }
+                ghost int myGhost(int y)
+                """;
+
+        RJLexer lexer = new RJLexer(CharStreams.fromString(input));
+        CommonTokenStream tokens = new CommonTokenStream(lexer);
+        RJParser parser = new RJParser(tokens);
+
+        RJParser.ProgContext ctx = parser.prog();
+
+        assertNotNull(ctx, "O contexto do programa não deve ser nulo");
+        assertNotNull(ctx.start(), "Deve conter uma regra start válida");
+        assertEquals(0, parser.getNumberOfSyntaxErrors(), "O parser não deve gerar erros");
+    }
+}
\ No newline at end of file
diff --git a/liquidjava-verifier/src/test/java/rj/grammar/RJParserLiteralTest.java b/liquidjava-verifier/src/test/java/rj/grammar/RJParserLiteralTest.java
new file mode 100644
index 00000000..4c1356bf
--- /dev/null
+++ b/liquidjava-verifier/src/test/java/rj/grammar/RJParserLiteralTest.java
@@ -0,0 +1,34 @@
+package rj.grammar;
+
+import org.antlr.v4.runtime.*;
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.Test;
+
+public class RJParserLiteralTest {
+
+    @Test
+    void testIntegerLiteral() {
+        String input = "123";
+        RJLexer lexer = new RJLexer(CharStreams.fromString(input));
+        CommonTokenStream tokens = new CommonTokenStream(lexer);
+        RJParser parser = new RJParser(tokens);
+
+        RJParser.LiteralContext ctx = parser.literal();
+
+        assertNotNull(ctx);
+        assertEquals("123", ctx.getText());
+    }
+
+    @Test
+    void testBooleanLiteral() {
+        String input = "true";
+        RJLexer lexer = new RJLexer(CharStreams.fromString(input));
+        CommonTokenStream tokens = new CommonTokenStream(lexer);
+        RJParser parser = new RJParser(tokens);
+
+        RJParser.LiteralContext ctx = parser.literal();
+
+        assertNotNull(ctx);
+        assertEquals("true", ctx.getText());
+    }
+}
\ No newline at end of file
diff --git a/liquidjava-verifier/src/test/java/rj/grammar/RJParserTest.java b/liquidjava-verifier/src/test/java/rj/grammar/RJParserTest.java
new file mode 100644
index 00000000..2c9b2fdc
--- /dev/null
+++ b/liquidjava-verifier/src/test/java/rj/grammar/RJParserTest.java
@@ -0,0 +1,21 @@
+package rj.grammar;
+
+import org.antlr.v4.runtime.*;
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.Test;
+
+public class RJParserTest {
+
+    @Test
+    void testLiteralParsing() {
+        String input = "42";
+        RJLexer lexer = new RJLexer(CharStreams.fromString(input));
+        CommonTokenStream tokens = new CommonTokenStream(lexer);
+        RJParser parser = new RJParser(tokens);
+
+        RJParser.LiteralContext context = parser.literal();
+
+        assertNotNull(context);
+        assertEquals("42", context.getText());
+    }
+}
\ No newline at end of file