diff --git a/.github/workflows/maven.yml b/.github/workflows/maven.yml
index fe7a72f..839e71b 100644
--- a/.github/workflows/maven.yml
+++ b/.github/workflows/maven.yml
@@ -1,32 +1,35 @@
-# This workflow will build a Java project with Maven, and cache/restore any dependencies to improve the workflow execution time
-# For more information see: https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-java-with-maven
+name: Java Maven Tests
 
-# This workflow uses actions that are not certified by GitHub.
-# They are provided by a third-party and are governed by
-# separate terms of service, privacy policy, and support
-# documentation.
-
-
-name: Java CI with Maven
-
-on: [push, pull_request]
+on:
+  push:
+    branches: [ main, develop ]
+  pull_request:
+    branches: [ main, develop ]
 
 jobs:
   build:
-    permissions: write-all
     runs-on: ubuntu-latest
 
+    strategy:
+      matrix:
+        java-version: ['11', '17']
+
     steps:
     - uses: actions/checkout@v3
-    - name: Set up JDK 17
+    
+    - name: Set up JDK ${{ matrix.java-version }}
       uses: actions/setup-java@v3
       with:
-        java-version: '17'
-        distribution: 'zulu'
+        java-version: ${{ matrix.java-version }}
+        distribution: 'temurin'
         cache: maven
 
     - name: Build with Maven
-      run: mvn -B package --file pom.xml
+      run: mvn -B compile --file pom.xml
+
+    - name: Run tests with Maven
+      run: mvn -B test --file pom.xml
 
-    - name: Run the Maven verify phase
-      run: mvn --batch-mode --update-snapshots verify
+    - name: Generate test report
+      if: always()
+      run: mvn -B surefire-report:report --file pom.xml
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..4421762
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,11 @@
+target/
+.classpath
+.project
+.settings/
+*.class
+*.jar
+*.log
+.DS_Store
+.vscode/
+.idea/
+*.iml
diff --git a/pom.xml b/pom.xml
new file mode 100644
index 0000000..45c131b
--- /dev/null
+++ b/pom.xml
@@ -0,0 +1,47 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>com.mycompany.app</groupId>
+  <artifactId>my-app</artifactId>
+  <version>1.0-SNAPSHOT</version>
+
+  <name>my-app</name>
+  <description>Maven Project with Square Root Calculator Tests</description>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    <maven.compiler.source>11</maven.compiler.source>
+    <maven.compiler.target>11</maven.compiler.target>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>4.13.2</version>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>3.8.1</version>
+        <configuration>
+          <source>11</source>
+          <target>11</target>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <version>2.22.2</version>
+      </plugin>
+    </plugins>
+  </build>
+</project>
diff --git a/src/main/java/com/mycompany/app/App.java b/src/main/java/com/mycompany/app/App.java
new file mode 100644
index 0000000..1dab526
--- /dev/null
+++ b/src/main/java/com/mycompany/app/App.java
@@ -0,0 +1,10 @@
+package com.mycompany.app;
+
+public class App {
+    public static void main(String[] args) {
+        double val = Double.parseDouble("2.0");
+        Sqrt sqrt = new Sqrt(val);
+        double result = sqrt.calc();
+        System.out.println("Sqrt of " + val + " = " + result);
+    }
+}
diff --git a/src/main/java/com/mycompany/app/Sqrt.java b/src/main/java/com/mycompany/app/Sqrt.java
new file mode 100644
index 0000000..db99b11
--- /dev/null
+++ b/src/main/java/com/mycompany/app/Sqrt.java
@@ -0,0 +1,56 @@
+package com.mycompany.app;
+
+public class Sqrt {
+    private static final double DEFAULT_DELTA = 0.00000001;
+    private double delta;
+    private double arg;
+
+    public Sqrt(double arg) {
+        this(arg, DEFAULT_DELTA);
+    }
+
+    public Sqrt(double arg, double delta) {
+        this.arg = arg;
+        this.delta = delta;
+    }
+
+    public double average(double x, double y) {
+        return (x + y) / 2.0;
+    }
+
+    public boolean good(double guess, double x) {
+        return Math.abs(guess * guess - x) < delta;
+    }
+
+    public double improve(double guess, double x) {
+        return average(guess, x / guess);
+    }
+
+    public double iter(double guess, double x) {
+        while (!good(guess, x)) {
+            guess = improve(guess, x);
+        }
+        return guess;
+    }
+
+    public double calc() {
+        if (arg < 0)
+            throw new IllegalArgumentException("Argument must be non-negative: " + arg);
+        if (arg == 0.0)
+            return 0.0;
+        double initialGuess = (arg >= 1.0) ? arg / 2.0 : 1.0;
+        return iter(initialGuess, arg);
+    }
+
+    public double getArg() {
+        return arg;
+    }
+
+    public double getDelta() {
+        return delta;
+    }
+
+    public void setDelta(double delta) {
+        this.delta = delta;
+    }
+}
diff --git a/src/test/java/com/mycompany/app/AppTest.java b/src/test/java/com/mycompany/app/AppTest.java
new file mode 100644
index 0000000..16377d6
--- /dev/null
+++ b/src/test/java/com/mycompany/app/AppTest.java
@@ -0,0 +1,211 @@
+package com.mycompany.app;
+
+import org.junit.Test;
+import org.junit.Before;
+import static org.junit.Assert.*;
+
+public class AppTest {
+    private Sqrt sqrt;
+    private static final double EPSILON = 1e-6;
+
+    @Before
+    public void setUp() {
+        sqrt = new Sqrt(2.0);
+    }
+
+    @Test
+    public void testConstructorDefaultDelta() {
+        Sqrt s = new Sqrt(4.0);
+        assertEquals(4.0, s.getArg(), EPSILON);
+        assertEquals(0.00000001, s.getDelta(), EPSILON);
+    }
+
+    @Test
+    public void testConstructorCustomDelta() {
+        Sqrt s = new Sqrt(9.0, 0.0001);
+        assertEquals(9.0, s.getArg(), EPSILON);
+        assertEquals(0.0001, s.getDelta(), EPSILON);
+    }
+
+    @Test
+    public void testAveragePositive() {
+        double result = sqrt.average(4.0, 6.0);
+        assertEquals(5.0, result, EPSILON);
+    }
+
+    @Test
+    public void testAverageNegative() {
+        double result = sqrt.average(-2.0, -4.0);
+        assertEquals(-3.0, result, EPSILON);
+    }
+
+    @Test
+    public void testAverageWithZero() {
+        double result = sqrt.average(0.0, 10.0);
+        assertEquals(5.0, result, EPSILON);
+    }
+
+    @Test
+    public void testGoodReturnsTrueWhenCloseEnough() {
+        Sqrt s = new Sqrt(4.0);
+        boolean result = s.good(2.0, 4.0);
+        assertTrue(result);
+    }
+
+    @Test
+    public void testGoodReturnsFalseWhenNotCloseEnough() {
+        Sqrt s = new Sqrt(4.0);
+        boolean result = s.good(1.5, 4.0);
+        assertFalse(result);
+    }
+
+    @Test
+    public void testImprove() {
+        Sqrt s = new Sqrt(2.0);
+        double initialGuess = 1.5;
+        double improved = s.improve(initialGuess, 2.0);
+        assertEquals(1.416666666, improved, EPSILON);
+    }
+
+    @Test
+    public void testIter() {
+        Sqrt s = new Sqrt(4.0);
+        double result = s.iter(1.0, 4.0);
+        assertEquals(2.0, result, EPSILON);
+    }
+
+    @Test
+    public void testCalcPerfectSquare4() {
+        Sqrt s = new Sqrt(4.0);
+        double result = s.calc();
+        assertEquals(2.0, result, EPSILON);
+    }
+
+    @Test
+    public void testCalcPerfectSquare9() {
+        Sqrt s = new Sqrt(9.0);
+        double result = s.calc();
+        assertEquals(3.0, result, EPSILON);
+    }
+
+    @Test
+    public void testCalcNonPerfectSquare2() {
+        Sqrt s = new Sqrt(2.0);
+        double result = s.calc();
+        assertEquals(Math.sqrt(2.0), result, EPSILON);
+        assertTrue(Math.abs(result - 1.414213562) < 0.0001);
+    }
+
+    @Test
+    public void testCalcOne() {
+        Sqrt s = new Sqrt(1.0);
+        double result = s.calc();
+        assertEquals(1.0, result, EPSILON);
+    }
+
+    @Test
+    public void testCalcSmallDecimal() {
+        Sqrt s = new Sqrt(0.25);
+        double result = s.calc();
+        assertEquals(0.5, result, EPSILON);
+    }
+
+    @Test
+    public void testCalcLargeNumber() {
+        Sqrt s = new Sqrt(100.0);
+        double result = s.calc();
+        assertEquals(10.0, result, EPSILON);
+    }
+
+    @Test
+    public void testCalcVeryLargeNumber() {
+        Sqrt s = new Sqrt(10000.0);
+        double result = s.calc();
+        assertEquals(100.0, result, EPSILON);
+    }
+
+    @Test
+    public void testGetDelta() {
+        Sqrt s = new Sqrt(5.0, 0.001);
+        assertEquals(0.001, s.getDelta(), EPSILON);
+    }
+
+    @Test
+    public void testSetDelta() {
+        Sqrt s = new Sqrt(5.0);
+        s.setDelta(0.01);
+        assertEquals(0.01, s.getDelta(), EPSILON);
+    }
+
+    @Test
+    public void testGetArg() {
+        Sqrt s = new Sqrt(7.5);
+        assertEquals(7.5, s.getArg(), EPSILON);
+    }
+
+    @Test
+    public void testHigherPrecision() {
+        Sqrt s = new Sqrt(2.0, 0.00000001);
+        double result = s.calc();
+        double expectedSqrt2 = 1.41421356237;
+        assertEquals(expectedSqrt2, result, 0.00000001);
+    }
+
+    @Test
+    public void testCalcFractional() {
+        Sqrt s = new Sqrt(3.0);
+        double result = s.calc();
+        assertEquals(Math.sqrt(3.0), result, EPSILON);
+        assertTrue(Math.abs(result - 1.732050808) < 0.0001);
+    }
+
+    @Test
+    public void testCalcGoldenRatio() {
+        double phi = (1.0 + Math.sqrt(5.0)) / 2.0;
+        Sqrt s = new Sqrt(phi * phi);
+        double result = s.calc();
+        assertEquals(phi, result, EPSILON);
+    }
+
+    @Test
+    public void testMultipleCalcsWithSameObject() {
+        Sqrt s1 = new Sqrt(4.0);
+        double result1 = s1.calc();
+        assertEquals(2.0, result1, EPSILON);
+
+        Sqrt s2 = new Sqrt(9.0);
+        double result2 = s2.calc();
+        assertEquals(3.0, result2, EPSILON);
+    }
+
+    @Test
+    public void testAverageSameNumbers() {
+        double result = sqrt.average(5.0, 5.0);
+        assertEquals(5.0, result, EPSILON);
+    }
+
+    @Test
+    public void testGoodWithExactMatch() {
+        Sqrt s = new Sqrt(1.0, 0.00000001);
+        boolean result = s.good(1.0, 1.0);
+        assertTrue(result);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testNegativeArgThrows() {
+        Sqrt s = new Sqrt(-4.0);
+        s.calc();
+    }
+
+    @Test
+    public void testUniqueRandomCases() {
+        long seed = System.currentTimeMillis() ^ System.getProperty("user.name").hashCode();
+        java.util.Random rnd = new java.util.Random(seed);
+        for (int i = 0; i < 50; i++) {
+            double val = 1e-6 + rnd.nextDouble() * 1e6; // range [1e-6, 1e6+1e-6]
+            Sqrt s = new Sqrt(val, 1e-7);
+            double result = s.calc();
+            assertEquals(Math.sqrt(val), result, 1e-6);
+        }
+    }
+}