CAMEL-21208: Add unit test for TemplateHelper

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: gnodet

dsl/camel-jbang/camel-jbang-core/src/test/java/org/apache/camel/dsl/jbang/core/common/TemplateHelperTest.java

@@ -0,0 +1,122 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.camel.dsl.jbang.core.common;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class TemplateHelperTest {
+
+    @Test
+    void testSimpleInterpolation() throws IOException {
+        Map<String, Object> model = new HashMap<>();
+        model.put("Name", "MyRoute");
+        model.put("Code", "from(\"timer:tick\").log(\"Hello\");");
+
+        String result = TemplateHelper.processTemplate("code-java.ftl", model);
+
+        assertTrue(result.contains("class MyRoute"), "Should contain class name");
+        assertTrue(result.contains("from(\"timer:tick\").log(\"Hello\");"), "Should contain code");
+        assertFalse(result.contains("[="), "Should not contain unresolved interpolations");
+    }
+
+    @Test
+    void testLicenseHeaderStripped() throws IOException {
+        Map<String, Object> model = new HashMap<>();
+        model.put("Name", "Test");
+        model.put("Code", "// test");
+
+        String result = TemplateHelper.processTemplate("code-java.ftl", model);
+
+        assertFalse(result.contains("<#--"), "License header should be stripped");
+        assertFalse(result.contains("Licensed to the Apache"), "License text should be stripped");
+    }
+
+    @Test
+    void testConditionalRendering() throws IOException {
+        // main.ftl has [#if PackageName??] conditional
+        Map<String, Object> withPackage = new HashMap<>();
+        withPackage.put("PackageName", "package com.example;");
+        withPackage.put("MainClassname", "MyApp");
+
+        String result = TemplateHelper.processTemplate("main.ftl", withPackage);
+        assertTrue(result.contains("package com.example;"), "Should contain package declaration");
+        assertTrue(result.contains("class MyApp"), "Should contain class name");
+
+        // Without package
+        Map<String, Object> withoutPackage = new HashMap<>();
+        withoutPackage.put("MainClassname", "MyApp");
+
+        result = TemplateHelper.processTemplate("main.ftl", withoutPackage);
+        assertFalse(result.contains("package "), "Should not contain package declaration");
+        assertTrue(result.contains("class MyApp"), "Should contain class name");
+    }
+
+    @Test
+    void testListRendering() throws IOException {
+        Map<String, Object> model = new HashMap<>();
+        model.put("GroupId", "com.example");
+        model.put("ArtifactId", "my-app");
+        model.put("Version", "1.0.0");
+        model.put("SpringBootVersion", "3.4.0");
+        model.put("JavaVersion", "21");
+        model.put("CamelSpringBootVersion", "4.10.0");
+        model.put("ProjectBuildOutputTimestamp", "2024-01-01T00:00:00Z");
+        model.put("BuildProperties", "");
+        model.put("Repositories", List.of());
+
+        List<Map<String, Object>> deps = List.of(
+                Map.of("groupId", "org.apache.camel.springboot", "artifactId", "camel-timer-starter",
+                        "isLib", false, "isKameletsUtils", false));
+
+        model.put("Dependencies", deps);
+
+        String result = TemplateHelper.processTemplate("spring-boot-pom.ftl", model);
+        assertTrue(result.contains("<groupId>com.example</groupId>"), "Should contain groupId");
+        assertTrue(result.contains("<artifactId>camel-timer-starter</artifactId>"),
+                "Should contain dependency artifactId");
+        // Maven ${...} expressions should pass through unmodified
+        assertTrue(result.contains("${project.basedir}") || !result.contains("isLib"),
+                "Maven expressions should not be interpreted by FreeMarker");
+    }
+
+    @Test
+    void testMavenExpressionsPreserved() throws IOException {
+        Map<String, Object> model = new HashMap<>();
+        model.put("ArtifactId", "my-app");
+        model.put("Version", "1.0.0");
+        model.put("AppJar", "my-app-1.0.0.jar");
+
+        String result = TemplateHelper.processTemplate("Dockerfile21.ftl", model);
+        assertTrue(result.contains("my-app"), "Should contain artifact id");
+        assertFalse(result.contains("[="), "Should not contain unresolved interpolations");
+    }
+
+    @Test
+    void testMissingTemplateThrowsIOException() {
+        Map<String, Object> model = new HashMap<>();
+        assertThrows(IOException.class, () -> TemplateHelper.processTemplate("nonexistent.ftl", model));
+    }
+}