feat(scripting): add kotlin script (JSR-223) support

README.md

@@ -32,6 +32,7 @@ Available script languages:
 * [groovy](http://groovy-lang.org/)
 * [feel](https://github.com/camunda/feel-scala)
 * [mustache](http://mustache.github.io/mustache.5.html)
+* [kotlin](https://kotlinlang.org/)
 
 ## Install
 

pom.xml

@@ -21,6 +21,7 @@
 
         <version.groovy>2.4.20</version.groovy>
         <version.feel>1.12.3</version.feel>
+        <version.kotlin>1.4.10</version.kotlin>
 
         <version.spring.boot>2.3.5.RELEASE</version.spring.boot>
         <version.java>11</version.java>
@@ -51,6 +52,14 @@
                 <type>pom</type>
             </dependency>
 
+            <dependency>
+                <groupId>org.jetbrains.kotlin</groupId>
+                <artifactId>kotlin-bom</artifactId>
+                <version>${version.kotlin}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+
             <dependency>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-dependencies</artifactId>
@@ -111,6 +120,12 @@
             <version>${version.feel}</version>
         </dependency>
 
+        <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-scripting-jsr223</artifactId>
+            <version>${version.kotlin}</version>
+        </dependency>
+
         <!-- test -->
         <dependency>
             <groupId>junit</groupId>
@@ -155,6 +170,17 @@
                         </goals>
                     </execution>
                 </executions>
+                <configuration>
+                    <!-- Needs to unpack this dependency.
+                     See: https://github.com/sdeleuze/kotlin-script-templating/issues/7#issuecomment-364572513
+                     -->
+                    <requiresUnpack>
+                        <dependency>
+                            <groupId>org.jetbrains.kotlin</groupId>
+                            <artifactId>kotlin-compiler-embeddable</artifactId>
+                        </dependency>
+                    </requiresUnpack>
+                </configuration>
             </plugin>
 
             <plugin>

src/test/java/io/zeebe/script/EvaluationKotlinTest.java

@@ -0,0 +1,61 @@
+package io.zeebe.script;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.entry;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import org.junit.Test;
+
+public class EvaluationKotlinTest {
+
+  private final ScriptEvaluator scriptEvaluator = new ScriptEvaluator();
+
+  @Test
+  public void shouldReturnNumber() {
+    final Object result =
+        scriptEvaluator.evaluate("kotlin", "x * 2", Collections.singletonMap("x", 2));
+
+    assertThat(result).isEqualTo(4);
+  }
+
+  @Test
+  public void shouldReturnString() {
+    final Object result =
+        scriptEvaluator.evaluate("kotlin", "\"url?id=\" + id", Collections.singletonMap("id", "123"));
+
+    assertThat(result).isEqualTo("url?id=123");
+  }
+
+  @Test
+  public void shouldReturnList() {
+    @SuppressWarnings("unchecked")
+    final List<Object> result =
+        (List<Object>)
+            scriptEvaluator.evaluate("kotlin", "listOf(1, 2, x)", Collections.singletonMap("x", 3));
+
+    assertThat(result).hasSize(3).contains(1, 2, 3);
+  }
+
+  @Test
+  public void shouldReturnObject() {
+    @SuppressWarnings("unchecked")
+    final Map<String, Object> result =
+        (Map<String, Object>)
+            scriptEvaluator.evaluate(
+                "kotlin", "mapOf(\"foo\" to foo, \"bar\" to \"bar\")", Collections.singletonMap("foo", 123));
+
+    assertThat(result).hasSize(2).contains(entry("foo", 123), entry("bar", "bar"));
+  }
+
+  @Test
+  public void shouldReturnResultOfStringInterpolation() {
+
+    final Object result =
+        scriptEvaluator.evaluate(
+            "kotlin", "\"url?id=${id}\".toString()", Collections.singletonMap("id", 123));
+
+    assertThat(result).isEqualTo("url?id=123");
+  }
+}

src/test/java/io/zeebe/script/ScriptEvaluatorTest.java

@@ -46,6 +46,13 @@ public void shouldEvaluateFeel() {
     assertThat(result).isEqualTo(123L);
   }
 
+  @Test
+  public void shouldEvaluateKotlin() {
+    final Object result = scriptEvaluator.evaluate("kotlin", "123", Collections.emptyMap());
+
+    assertThat(result).isEqualTo(123);
+  }
+
   @Test
   public void shouldEvaluateJavaScriptWithVariables() {
 
@@ -72,6 +79,13 @@ public void shouldEvaluateFeelWithVariables() {
     assertThat(result).isEqualTo(123L);
   }
 
+  @Test
+  public void shouldEvaluateKotlinWithVariables() {
+    final Object result = scriptEvaluator.evaluate("kotlin", "a", Collections.singletonMap("a", 123));
+
+    assertThat(result).isEqualTo(123);
+  }
+
   @Test
   public void shouldThrowExceptionIfScriptEngineNotFound() {
     assertThatThrownBy(() -> scriptEvaluator.evaluate("foobar", "", Collections.emptyMap()))