re-organize testing modules

testing-modules/junit-4/src/main/java/com/baeldung/junit/Calculator.java

@@ -0,0 +1,11 @@
+package com.baeldung.junit;
+
+public class Calculator {
+    public int add(int a, int b) {
+        return a + b;
+    }
+
+    public int sub(int a, int b) {
+        return a - b;
+    }
+}

testing-modules/junit-4/src/test/java/com/baeldung/junit/AdditionUnitTest.java

@@ -0,0 +1,14 @@
+package com.baeldung.junit;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class AdditionUnitTest {
+    Calculator calculator = new Calculator();
+
+    @Test
+    public void testAddition() {
+        assertEquals("addition", 8, calculator.add(5, 3));
+    }
+}

testing-modules/junit-4/src/test/java/com/baeldung/junit/AssertionsUnitTest.java

@@ -0,0 +1,101 @@
+package com.baeldung.junit;
+
+import org.junit.Test;
+
+import java.util.Arrays;
+
+import static org.hamcrest.core.IsCollectionContaining.hasItems;
+import static org.junit.Assert.*;
+
+/**
+ * Unit test that demonstrate the different assertions available within JUnit 4
+ */
+public class AssertionsUnitTest {
+
+    @Test
+    public void whenAssertingEquality_thenEqual() {
+        String expected = "Baeldung";
+        String actual = "Baeldung";
+
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    public void whenAssertingEqualityWithMessage_thenEqual() {
+        String expected = "Baeldung";
+        String actual = "Baeldung";
+
+        assertEquals("failure - strings are not equal", expected, actual);
+    }
+
+    @Test
+    public void whenAssertingArraysEquality_thenEqual() {
+        char[] expected = { 'J', 'u', 'n', 'i', 't' };
+        char[] actual = "Junit".toCharArray();
+
+        assertArrayEquals(expected, actual);
+    }
+
+    @Test
+    public void givenNullArrays_whenAssertingArraysEquality_thenEqual() {
+        int[] expected = null;
+        int[] actual = null;
+
+        assertArrayEquals(expected, actual);
+    }
+
+    @Test
+    public void whenAssertingNull_thenTrue() {
+        Object car = null;
+
+        assertNull("The car should be null", car);
+    }
+
+    @Test
+    public void whenAssertingNotNull_thenTrue() {
+        Object car = new Object();
+
+        assertNotNull("The car should not be null", car);
+    }
+
+    @Test
+    public void whenAssertingNotSameObject_thenDifferent() {
+        Object cat = new Object();
+        Object dog = new Object();
+
+        assertNotSame(cat, dog);
+    }
+
+    @Test
+    public void whenAssertingSameObject_thenSame() {
+        Object cat = new Object();
+
+        assertSame(cat, cat);
+    }
+
+    @Test
+    public void whenAssertingConditions_thenVerified() {
+        assertTrue("5 is greater then 4", 5 > 4);
+        assertFalse("5 is not greater then 6", 5 > 6);
+    }
+
+    @Test
+    public void when_thenNotFailed() {
+        try {
+            methodThatShouldThrowException();
+            fail("Exception not thrown");
+        } catch (UnsupportedOperationException e) {
+            assertEquals("Operation Not Supported", e.getMessage());
+        }
+    }
+
+    private void methodThatShouldThrowException() {
+        throw new UnsupportedOperationException("Operation Not Supported");
+    }
+
+    @Test
+    public void testAssertThatHasItems() {
+        assertThat(Arrays.asList("Java", "Kotlin", "Scala"), hasItems("Java", "Kotlin"));
+    }
+
+}

testing-modules/junit-4/src/test/java/com/baeldung/junit/BlockingTestRunner.java

@@ -0,0 +1,18 @@
+package com.baeldung.junit;
+
+import org.junit.runners.BlockJUnit4ClassRunner;
+import org.junit.runners.model.FrameworkMethod;
+import org.junit.runners.model.InitializationError;
+import org.junit.runners.model.Statement;
+
+public class BlockingTestRunner extends BlockJUnit4ClassRunner {
+    public BlockingTestRunner(Class<?> klass) throws InitializationError {
+        super(klass);
+    }
+
+    @Override
+    protected Statement methodInvoker(FrameworkMethod method, Object test) {
+        System.out.println("invoking: " + method.getName());
+        return super.methodInvoker(method, test);
+    }
+}

testing-modules/junit-4/src/test/java/com/baeldung/junit/CalculatorUnitTest.java

@@ -0,0 +1,17 @@
+package com.baeldung.junit;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+import static org.junit.Assert.assertEquals;
+
+@RunWith(JUnit4.class)
+public class CalculatorUnitTest {
+    Calculator calculator = new Calculator();
+
+    @Test
+    public void testAddition() {
+        assertEquals("addition", 8, calculator.add(5, 3));
+    }
+}

testing-modules/junit-4/src/test/java/com/baeldung/junit/SubstractionUnitTest.java

@@ -0,0 +1,14 @@
+package com.baeldung.junit;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class SubstractionUnitTest {
+    Calculator calculator = new Calculator();
+
+    @Test
+    public void substraction() {
+        assertEquals("substraction", 2, calculator.sub(5, 3));
+    }
+}

testing-modules/junit-4/src/test/java/com/baeldung/junit/SuiteUnitTest.java

@@ -0,0 +1,12 @@
+package com.baeldung.junit;
+
+import org.junit.runner.RunWith;
+import org.junit.runners.Suite;
+import org.junit.runners.Suite.SuiteClasses;
+
+@RunWith(Suite.class)
+@SuiteClasses({
+  AdditionUnitTest.class,
+  SubstractionUnitTest.class})
+public class SuiteUnitTest {
+}

testing-modules/junit-4/src/test/java/com/baeldung/junit/TestRunner.java

@@ -0,0 +1,41 @@
+package com.baeldung.junit;
+
+import org.junit.Test;
+import org.junit.runner.Description;
+import org.junit.runner.Runner;
+import org.junit.runner.notification.RunNotifier;
+
+import java.lang.reflect.Method;
+
+public class TestRunner extends Runner {
+
+    private Class testClass;
+    public TestRunner(Class testClass) {
+        super();
+        this.testClass = testClass;
+    }
+
+    @Override
+    public Description getDescription() {
+        return Description.createTestDescription(testClass, "My runner description");
+    }
+
+    @Override
+    public void run(RunNotifier notifier) {
+        System.out.println("running the tests from MyRunner: " + testClass);
+        try {
+            Object testObject = testClass.newInstance();
+            for (Method method : testClass.getMethods()) {
+                if (method.isAnnotationPresent(Test.class)) {
+                    notifier.fireTestStarted(Description
+                      .createTestDescription(testClass, method.getName()));
+                    method.invoke(testObject);
+                    notifier.fireTestFinished(Description
+                      .createTestDescription(testClass, method.getName()));
+                }
+            }
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+}