Kotlin junit5 (#2672)

* Fixed the core-kotlin module to build, and set it up to run JUnit 5 tests using Failsafe

* Example JUnit5 tests in Kotlin

core-kotlin/pom.xml

@@ -5,6 +5,7 @@
 
     <artifactId>core-kotlin</artifactId>
     <version>1.0-SNAPSHOT</version>
+    <packaging>jar</packaging>
 
     <parent>
         <groupId>com.baeldung</groupId>
@@ -20,6 +21,24 @@
     </repositories>
 
     <dependencies>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <version>${junit.jupiter.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.platform</groupId>
+            <artifactId>junit-platform-runner</artifactId>
+            <version>${junit.platform.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>${junit4.version}</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.jetbrains.kotlin</groupId>
             <artifactId>kotlin-stdlib</artifactId>
@@ -116,16 +135,51 @@
                     </execution>
                 </executions>
             </plugin>
+            <plugin>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>${maven-surefire-plugin.version}</version>
+            </plugin>
+            <plugin>
+                <artifactId>maven-failsafe-plugin</artifactId>
+                <version>2.19.1</version>
+                <dependencies>
+                    <dependency>
+                        <groupId>org.junit.platform</groupId>
+                        <artifactId>junit-platform-surefire-provider</artifactId>
+                        <version>${junit.platform.version}</version>
+                    </dependency>
+                </dependencies>
+                <executions>
+                    <execution>
+                        <id>junit5</id>
+                        <goals>
+                            <goal>integration-test</goal>
+                            <goal>verify</goal>
+                        </goals>
+                        <configuration>
+                            <includes>
+                                <include>**/*Test5.java</include>
+                            </includes>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
         </plugins>
     </build>
 
     <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <kotlin-maven-plugin.version>1.1.2</kotlin-maven-plugin.version>
         <kotlin-test-junit.version>1.1.2</kotlin-test-junit.version>
         <kotlin-stdlib.version>1.1.2</kotlin-stdlib.version>
         <kotlin-reflect.version>1.1.2</kotlin-reflect.version>
         <kotlinx.version>0.15</kotlinx.version>
         <mockito-kotlin.version>1.5.0</mockito-kotlin.version>
+
+        <junit.jupiter.version>5.0.0</junit.jupiter.version>
+        <junit.platform.version>1.0.0</junit.platform.version>
+        <junit.vintage.version>4.12.0</junit.vintage.version>
+        <junit4.version>4.12</junit4.version>
     </properties>
 
-</project>
+</project>

core-kotlin/src/test/kotlin/com/baeldung/kotlin/junit5/Calculator.kt

@@ -0,0 +1,17 @@
+package com.baeldung.kotlin.junit5
+
+class Calculator {
+    fun add(a: Int, b: Int) = a + b
+
+    fun divide(a: Int, b: Int) = if (b == 0) {
+        throw DivideByZeroException(a)
+    } else {
+        a / b
+    }
+
+    fun square(a: Int) = a * a
+
+    fun squareRoot(a: Int) = Math.sqrt(a.toDouble())
+
+    fun log(base: Int, value: Int) = Math.log(value.toDouble()) / Math.log(base.toDouble())
+}

core-kotlin/src/test/kotlin/com/baeldung/kotlin/junit5/CalculatorTest5.kt

@@ -0,0 +1,82 @@
+package com.baeldung.kotlin.junit5
+
+import org.junit.jupiter.api.*
+import org.junit.jupiter.api.function.Executable
+
+class CalculatorTest5 {
+    private val calculator = Calculator()
+
+    @Test
+    fun testAddition() {
+        Assertions.assertEquals(4, calculator.add(1, 3))
+    }
+
+    @Test
+    fun testDivideByZero() {
+        val exception = Assertions.assertThrows(DivideByZeroException::class.java) {
+            calculator.divide(5, 0)
+        }
+
+        Assertions.assertEquals(5, exception.numerator)
+    }
+
+    @Test
+    fun testSquares() {
+        Assertions.assertAll(
+                Executable { Assertions.assertEquals(1, calculator.square(1)) },
+                Executable { Assertions.assertEquals(4, calculator.square(2)) },
+                Executable { Assertions.assertEquals(9, calculator.square(3)) }
+        )
+    }
+
+    @TestFactory
+    fun testSquaresFactory() = listOf(
+            DynamicTest.dynamicTest("1 squared") { Assertions.assertEquals(1,calculator.square(1))},
+            DynamicTest.dynamicTest("2 squared") { Assertions.assertEquals(4,calculator.square(2))},
+            DynamicTest.dynamicTest("3 squared") { Assertions.assertEquals(9,calculator.square(3))}
+    )
+
+    @TestFactory
+    fun testSquaresFactory2() = listOf(
+            1 to 1,
+            2 to 4,
+            3 to 9,
+            4 to 16,
+            5 to 25)
+            .map { (input, expected) ->
+                DynamicTest.dynamicTest("$input squared") {
+                    Assertions.assertEquals(expected, calculator.square(input))
+                }
+            }
+
+    private val squaresTestData = listOf(
+            1 to 1,
+            2 to 4,
+            3 to 9,
+            4 to 16,
+            5 to 25)
+
+    @TestFactory
+    fun testSquaresFactory3() = squaresTestData
+            .map { (input, expected) ->
+                DynamicTest.dynamicTest("$input squared") {
+                    Assertions.assertEquals(expected, calculator.square(input))
+                }
+            }
+    @TestFactory
+    fun testSquareRootsFactory3() = squaresTestData
+            .map { (expected, input) ->
+                DynamicTest.dynamicTest("Square root of $input") {
+                    Assertions.assertEquals(expected.toDouble(), calculator.squareRoot(input))
+                }
+            }
+
+    @Tags(
+            Tag("slow"),
+            Tag("logarithms")
+    )
+    @Test
+    fun testLogarithms() {
+        Assertions.assertEquals(3.0, calculator.log(2, 8))
+    }
+}

core-kotlin/src/test/kotlin/com/baeldung/kotlin/junit5/DivideByZeroException.kt

@@ -0,0 +1,3 @@
+package com.baeldung.kotlin.junit5
+
+class DivideByZeroException(val numerator: Int) : Exception()

core-kotlin/src/test/kotlin/com/baeldung/kotlin/junit5/SimpleTest5.kt

@@ -0,0 +1,21 @@
+package com.baeldung.kotlin.junit5
+
+import org.junit.jupiter.api.Assertions
+import org.junit.jupiter.api.Disabled
+import org.junit.jupiter.api.Test
+
+class SimpleTest5 {
+    @Test
+    fun testEmpty() {
+        val list = listOf<String>()
+        Assertions.assertTrue(list::isEmpty)
+    }
+
+    @Test
+    @Disabled
+    fun testMessage() {
+        Assertions.assertEquals(3, 4) {
+            "Three does not equal four"
+        }
+    }
+}