[KTLN-276] Run Kotlin Script (.kts) files from within Kotlin (#1126)

* unit tests

* code changes

* code changes

* code changes

* code changes

* code changes

* Added integration testing

* Code review cleanup

---------

Co-authored-by: Brandon Ward <[email protected]>

Author: albertache1998

core-kotlin-modules/core-kotlin-advanced-4/pom.xml

@@ -13,6 +13,12 @@
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 
+    <properties>
+        <kotlinx-html-jvm.version>0.7.5</kotlinx-html-jvm.version>
+        <kotlinx-coroutines.version>1.7.3</kotlinx-coroutines.version>
+        <kotlin-scripting.version>1.8.0</kotlin-scripting.version>
+    </properties>
+
     <dependencies>
 
         <dependency>
@@ -29,11 +35,32 @@
             <scope>test</scope>
         </dependency>
 
+        <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-scripting-jsr223</artifactId>
+            <version>${kotlin-scripting.version}</version>
+        </dependency>
+
     </dependencies>
 
-    <properties>
-        <kotlinx-html-jvm.version>0.7.5</kotlinx-html-jvm.version>
-        <kotlinx-coroutines.version>1.7.3</kotlinx-coroutines.version>
-    </properties>
+    <profiles>
+        <profile>
+            <id>integration-test</id>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-surefire-plugin</artifactId>
+                        <version>2.22.2</version>
+                        <configuration>
+                            <includes>
+                                <include>**/*IntegrationTest.kt</include>
+                            </includes>
+                        </configuration>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
 
 </project>

core-kotlin-modules/core-kotlin-advanced-4/src/test/kotlin/com/baeldung/runKotlinScripts/RunKotlinScriptsIntegrationTest.kt

@@ -0,0 +1,25 @@
+package com.baeldung.runKotlinScripts
+
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Test
+import java.io.File
+
+// requires `kotlinc` to be installed on the machine.
+class RunKotlinScriptsIntegrationTest {
+    @Test
+    fun `run Kotlin script with ProcessBuilder`() {
+        val scriptFile = File.createTempFile("test", ".kts")
+        scriptFile.writeText("""
+        println("Hello, ProcessBuilder!")
+        """.trimIndent())
+
+        val output = runScriptUsingProcess(scriptFile.absolutePath).trim()
+        assertEquals("Hello, ProcessBuilder!", output)
+    }
+}
+
+fun runScriptUsingProcess(scriptPath: String): String {
+    val processBuilder = ProcessBuilder("kotlinc", "-script", scriptPath)
+    val process = processBuilder.start()
+    return process.inputStream.bufferedReader().use { it.readText() }
+}

core-kotlin-modules/core-kotlin-advanced-4/src/test/kotlin/com/baeldung/runKotlinScripts/RunKotlinScriptsUnitTest.kt

@@ -0,0 +1,43 @@
+package com.baeldung.runKotlinScripts
+
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Test
+import java.io.ByteArrayOutputStream
+import java.io.File
+import java.io.PrintStream
+import javax.script.ScriptEngineManager
+
+class RunKotlinScriptsUnitTest {
+
+    @Test
+    fun `run Kotlin script using ScriptEngine`() {
+        val scriptFile = File.createTempFile("test", ".kts")
+        scriptFile.writeText("""
+        println("Hello from ScriptEngine!")
+    """.trimIndent())
+
+        val output = runKotlinScriptWithEngine(scriptFile.absolutePath).trim()
+
+        assertEquals("Hello from ScriptEngine!", output)
+    }
+
+
+}
+
+fun runKotlinScriptWithEngine(scriptPath: String): String {
+    val engine = ScriptEngineManager().getEngineByExtension("kts")
+    val script = File(scriptPath).readText()
+
+    val outputStream = ByteArrayOutputStream()
+    val originalOut = System.out
+    System.setOut(PrintStream(outputStream))
+
+    try {
+        engine.eval(script)
+    } finally {
+        System.setOut(originalOut)
+    }
+
+    return outputStream.toString()
+}
+

core-kotlin-modules/core-kotlin-advanced-4/src/test/kotlin/com/baeldung/runKotlinScripts/my-script.kts

@@ -0,0 +1 @@
+println("Hello, KScript!")