Review TemplateRenderer abstraction

Closes gh-818

initializr-docs/src/main/asciidoc/configuration-guide.adoc

@@ -808,4 +808,7 @@ expiration settings accordingly.
 |`initializr.project-resources`
 |Cache resources that are used to generate projects.
 
+|`initializr.templates`
+|Cache templates that are used to generate projects.
+
 |===

initializr-generator/src/main/java/io/spring/initializr/generator/io/template/MustacheTemplateRenderer.java

@@ -0,0 +1,100 @@
+/*
+ * Copyright 2012-2019 the original author or authors.
+ *
+ * Licensed 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 io.spring.initializr.generator.io.template;
+
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.nio.charset.StandardCharsets;
+import java.util.Map;
+import java.util.function.Function;
+
+import com.samskivert.mustache.Mustache;
+import com.samskivert.mustache.Mustache.Compiler;
+import com.samskivert.mustache.Mustache.TemplateLoader;
+import com.samskivert.mustache.Template;
+
+import org.springframework.cache.Cache;
+import org.springframework.cache.Cache.ValueRetrievalException;
+import org.springframework.core.io.DefaultResourceLoader;
+import org.springframework.core.io.ResourceLoader;
+
+/**
+ * A {@link TemplateRenderer} using Mustache.
+ *
+ * @author Stephane Nicoll
+ */
+public class MustacheTemplateRenderer implements TemplateRenderer {
+
+	private final Compiler mustache;
+
+	private final Function<String, String> keyGenerator;
+
+	private final Cache templateCache;
+
+	public MustacheTemplateRenderer(String resourcePrefix, Cache templateCache) {
+		String prefix = (resourcePrefix.endsWith("/") ? resourcePrefix
+				: resourcePrefix + "/");
+		this.mustache = Mustache.compiler().withLoader(mustacheTemplateLoader(prefix));
+		this.keyGenerator = (name) -> String.format("%s%s", prefix, name);
+		this.templateCache = templateCache;
+	}
+
+	public MustacheTemplateRenderer(String resourcePrefix) {
+		this(resourcePrefix, null);
+	}
+
+	private static TemplateLoader mustacheTemplateLoader(String prefix) {
+		ResourceLoader resourceLoader = new DefaultResourceLoader();
+		return (name) -> {
+			String location = prefix + name + ".mustache";
+			return new InputStreamReader(
+					resourceLoader.getResource(location).getInputStream(),
+					StandardCharsets.UTF_8);
+		};
+	}
+
+	@Override
+	public String render(String templateName, Map<String, ?> model) throws IOException {
+		Template template = getTemplate(templateName);
+		return template.execute(model);
+	}
+
+	private Template getTemplate(String name) {
+		try {
+			if (this.templateCache != null) {
+				try {
+					return this.templateCache.get(this.keyGenerator.apply(name),
+							() -> loadTemplate(name));
+				}
+				catch (ValueRetrievalException ex) {
+					throw ex.getCause();
+				}
+			}
+			return loadTemplate(name);
+		}
+		catch (Throwable ex) {
+			throw new IllegalStateException("Cannot load template " + name, ex);
+		}
+	}
+
+	private Template loadTemplate(String name) throws Exception {
+		Reader template = this.mustache.loader.getTemplate(name);
+		return this.mustache.compile(template);
+	}
+
+}

initializr-generator/src/main/java/io/spring/initializr/generator/io/template/TemplateRenderer.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2012-2019 the original author or authors.
+ *
+ * Licensed 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 io.spring.initializr.generator.io.template;
+
+import java.io.IOException;
+import java.util.Map;
+
+/**
+ * Template rendering abstraction.
+ *
+ * @author Stephane Nicoll
+ */
+@FunctionalInterface
+public interface TemplateRenderer {
+
+	/**
+	 * Render the template with the specified name and the specified model.
+	 * @param templateName the name of the template
+	 * @param model the model to use
+	 * @return the rendering result
+	 * @throws IOException if rendering the template failed
+	 */
+	String render(String templateName, Map<String, ?> model) throws IOException;
+
+}

initializr-generator/src/main/java/io/spring/initializr/generator/io/template/package-info.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2012-2019 the original author or authors.
+ *
+ * Licensed 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.
+ */
+
+/**
+ * Template rendering abstraction.
+ */
+package io.spring.initializr.generator.io.template;

initializr-generator/src/main/java/io/spring/initializr/util/TemplateRenderer.java

@@ -1,108 +0,0 @@
-/*
- * Copyright 2012-2018 the original author or authors.
- *
- * Licensed 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 io.spring.initializr.util;
-
-import java.io.InputStreamReader;
-import java.io.Reader;
-import java.nio.charset.Charset;
-import java.util.Map;
-import java.util.concurrent.ConcurrentMap;
-
-import com.samskivert.mustache.Mustache;
-import com.samskivert.mustache.Mustache.Compiler;
-import com.samskivert.mustache.Mustache.TemplateLoader;
-import com.samskivert.mustache.Template;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import org.springframework.core.io.DefaultResourceLoader;
-import org.springframework.core.io.ResourceLoader;
-import org.springframework.util.ConcurrentReferenceHashMap;
-
-/**
- * A template renderer backed by Mustache.
- *
- * @author Dave Syer
- */
-public class TemplateRenderer {
-
-	private static final Logger log = LoggerFactory.getLogger(TemplateRenderer.class);
-
-	private boolean cache = true;
-
-	private final Compiler mustache;
-
-	private final ConcurrentMap<String, Template> templateCaches = new ConcurrentReferenceHashMap<>();
-
-	public TemplateRenderer() {
-		this(mustacheCompiler());
-	}
-
-	public TemplateRenderer(Compiler mustache) {
-		this.mustache = mustache;
-	}
-
-	public boolean isCache() {
-		return this.cache;
-	}
-
-	public void setCache(boolean cache) {
-		this.cache = cache;
-	}
-
-	public String process(String name, Map<String, ?> model) {
-		try {
-			Template template = getTemplate(name);
-			return template.execute(model);
-		}
-		catch (Exception ex) {
-			log.error("Cannot render: " + name, ex);
-			throw new IllegalStateException("Cannot render template", ex);
-		}
-	}
-
-	public Template getTemplate(String name) {
-		if (this.cache) {
-			return this.templateCaches.computeIfAbsent(name, this::loadTemplate);
-		}
-		return loadTemplate(name);
-	}
-
-	protected Template loadTemplate(String name) {
-		try {
-			Reader template;
-			template = this.mustache.loader.getTemplate(name);
-			return this.mustache.compile(template);
-		}
-		catch (Exception ex) {
-			throw new IllegalStateException("Cannot load template " + name, ex);
-		}
-	}
-
-	private static Compiler mustacheCompiler() {
-		return Mustache.compiler().withLoader(mustacheTemplateLoader());
-	}
-
-	private static TemplateLoader mustacheTemplateLoader() {
-		ResourceLoader resourceLoader = new DefaultResourceLoader();
-		String prefix = "classpath:/templates/";
-		Charset charset = Charset.forName("UTF-8");
-		return (name) -> new InputStreamReader(
-				resourceLoader.getResource(prefix + name).getInputStream(), charset);
-	}
-
-}

initializr-generator/src/test/java/io/spring/initializr/generator/io/template/MustacheTemplateRendererTests.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright 2012-2019 the original author or authors.
+ *
+ * Licensed 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 io.spring.initializr.generator.io.template;
+
+import java.io.IOException;
+import java.util.Collections;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.cache.Cache;
+import org.springframework.cache.concurrent.ConcurrentMapCache;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+
+/**
+ * Tests for {@link MustacheTemplateRenderer}.
+ *
+ * @author Stephane Nicoll
+ */
+class MustacheTemplateRendererTests {
+
+	private final Cache templatesCache = new ConcurrentMapCache("test");
+
+	@Test
+	void renderTemplate() throws IOException {
+		MustacheTemplateRenderer render = new MustacheTemplateRenderer(
+				"classpath:/templates/mustache", this.templatesCache);
+		assertThat(this.templatesCache.get("classpath:/templates/mustache/test"))
+				.isNull();
+		assertThat(render.render("test", Collections.singletonMap("key", "value")))
+				.isEqualTo("value");
+		assertThat(this.templatesCache.get("classpath:/templates/mustache/test"))
+				.isNotNull();
+	}
+
+	@Test
+	void renderTemplateWithoutCache() throws IOException {
+		MustacheTemplateRenderer render = new MustacheTemplateRenderer(
+				"classpath:/templates/mustache");
+		assertThat(render.render("test", Collections.singletonMap("key", "value")))
+				.isEqualTo("value");
+	}
+
+	@Test
+	void renderUnknownTemplate() {
+		MustacheTemplateRenderer render = new MustacheTemplateRenderer(
+				"classpath:/templates/mustache", this.templatesCache);
+		assertThatExceptionOfType(IllegalStateException.class)
+				.isThrownBy(() -> render.render("does-not-exist", Collections.emptyMap()))
+				.withMessageContaining("Cannot load template")
+				.withMessageContaining("does-not-exist");
+	}
+
+}

initializr-generator/src/test/resources/templates/mustache/test.mustache

@@ -0,0 +1 @@
+{{key}}

initializr-web/src/main/java/io/spring/initializr/web/autoconfigure/InitializrAutoConfiguration.java

@@ -25,13 +25,14 @@ import javax.cache.expiry.Duration;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import io.spring.initializr.generator.io.IndentingWriterFactory;
 import io.spring.initializr.generator.io.SimpleIndentStrategy;
+import io.spring.initializr.generator.io.template.MustacheTemplateRenderer;
+import io.spring.initializr.generator.io.template.TemplateRenderer;
 import io.spring.initializr.generator.project.ProjectDirectoryFactory;
 import io.spring.initializr.metadata.DependencyMetadataProvider;
 import io.spring.initializr.metadata.InitializrMetadata;
 import io.spring.initializr.metadata.InitializrMetadataBuilder;
 import io.spring.initializr.metadata.InitializrMetadataProvider;
 import io.spring.initializr.metadata.InitializrProperties;
-import io.spring.initializr.util.TemplateRenderer;
 import io.spring.initializr.web.ProjectResourceLocator;
 import io.spring.initializr.web.project.MainController;
 import io.spring.initializr.web.project.ProjectGenerationInvoker;
@@ -40,6 +41,7 @@ import io.spring.initializr.web.support.DefaultDependencyMetadataProvider;
 import io.spring.initializr.web.support.DefaultInitializrMetadataProvider;
 import io.spring.initializr.web.ui.UiController;
 
+import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.cache.JCacheManagerCustomizer;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
@@ -50,6 +52,9 @@ import org.springframework.boot.autoconfigure.web.client.RestTemplateAutoConfigu
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.boot.context.properties.bind.Binder;
 import org.springframework.boot.web.client.RestTemplateBuilder;
+import org.springframework.cache.Cache;
+import org.springframework.cache.CacheManager;
+import org.springframework.cache.support.NoOpCache;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.context.annotation.Bean;
@@ -84,12 +89,22 @@ public class InitializrAutoConfiguration {
 
 	@Bean
 	@ConditionalOnMissingBean
-	public TemplateRenderer templateRenderer(Environment environment) {
+	public TemplateRenderer templateRenderer(Environment environment,
-		Binder binder = Binder.get(environment);
+			ObjectProvider<CacheManager> cacheManager) {
-		boolean cache = binder.bind("spring.mustache.cache", Boolean.class).orElse(true);
+		return new MustacheTemplateRenderer("classpath:/templates",
-		TemplateRenderer templateRenderer = new TemplateRenderer();
+				determineCache(environment, cacheManager.getIfAvailable()));
-		templateRenderer.setCache(cache);
+	}
-		return templateRenderer;
+
+	private Cache determineCache(Environment environment, CacheManager cacheManager) {
+		if (cacheManager != null) {
+			Binder binder = Binder.get(environment);
+			boolean cache = binder.bind("spring.mustache.cache", Boolean.class)
+					.orElse(true);
+			if (cache) {
+				return cacheManager.getCache("initializr.templates");
+			}
+		}
+		return new NoOpCache("templates");
 	}
 
 	@Bean

initializr-web/src/main/java/io/spring/initializr/web/project/MainController.java

@@ -28,6 +28,7 @@ import java.util.concurrent.TimeUnit;
 import javax.servlet.http.HttpServletRequest;
 
 import com.samskivert.mustache.Mustache;
+import io.spring.initializr.generator.io.template.TemplateRenderer;
 import io.spring.initializr.generator.version.Version;
 import io.spring.initializr.metadata.DependencyMetadata;
 import io.spring.initializr.metadata.DependencyMetadataProvider;
@@ -35,7 +36,6 @@ import io.spring.initializr.metadata.InitializrMetadata;
 import io.spring.initializr.metadata.InitializrMetadataProvider;
 import io.spring.initializr.util.Agent;
 import io.spring.initializr.util.Agent.AgentId;
-import io.spring.initializr.util.TemplateRenderer;
 import io.spring.initializr.web.mapper.DependencyMetadataV21JsonMapper;
 import io.spring.initializr.web.mapper.InitializrMetadataJsonMapper;
 import io.spring.initializr.web.mapper.InitializrMetadataV21JsonMapper;
@@ -121,7 +121,8 @@ public class MainController extends AbstractInitializrController {
 
 	@RequestMapping(path = "/", produces = "text/plain")
 	public ResponseEntity<String> serviceCapabilitiesText(
-			@RequestHeader(value = HttpHeaders.USER_AGENT, required = false) String userAgent) {
+			@RequestHeader(value = HttpHeaders.USER_AGENT, required = false) String userAgent)
+			throws IOException {
 		String appUrl = generateAppUrl();
 		InitializrMetadata metadata = this.metadataProvider.get();
 

initializr-web/src/main/java/io/spring/initializr/web/support/CommandLineHelpGenerator.java

@@ -17,16 +17,17 @@
 package io.spring.initializr.web.support;
 
 import java.beans.PropertyDescriptor;
+import java.io.IOException;
 import java.util.Comparator;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.stream.Collectors;
 
+import io.spring.initializr.generator.io.template.TemplateRenderer;
 import io.spring.initializr.metadata.Dependency;
 import io.spring.initializr.metadata.InitializrMetadata;
 import io.spring.initializr.metadata.MetadataElement;
 import io.spring.initializr.metadata.Type;
-import io.spring.initializr.util.TemplateRenderer;
 
 import org.springframework.beans.BeanWrapperImpl;
 
@@ -56,12 +57,13 @@ public class CommandLineHelpGenerator {
 	 * @param metadata the initializr metadata
 	 * @param serviceUrl the service URL
 	 * @return the generic capabilities text document
+	 * @throws IOException if rendering the capabilities failed
 	 */
 	public String generateGenericCapabilities(InitializrMetadata metadata,
-			String serviceUrl) {
+			String serviceUrl) throws IOException {
 		Map<String, Object> model = initializeCommandLineModel(metadata, serviceUrl);
 		model.put("hasExamples", false);
-		return this.template.process("cli-capabilities.txt", model);
+		return this.template.render("cli/cli-capabilities", model);
 	}
 
 	/**
@@ -69,13 +71,14 @@ public class CommandLineHelpGenerator {
 	 * @param metadata the initializr metadata
 	 * @param serviceUrl the service URL
 	 * @return the generic capabilities text document
+	 * @throws IOException if rendering the capabilities failed
 	 */
-	public String generateCurlCapabilities(InitializrMetadata metadata,
+	public String generateCurlCapabilities(InitializrMetadata metadata, String serviceUrl)
-			String serviceUrl) {
+			throws IOException {
 		Map<String, Object> model = initializeCommandLineModel(metadata, serviceUrl);
-		model.put("examples", this.template.process("curl-examples.txt", model));
+		model.put("examples", this.template.render("cli/curl-examples", model));
 		model.put("hasExamples", true);
-		return this.template.process("cli-capabilities.txt", model);
+		return this.template.render("cli/cli-capabilities", model);
 	}
 
 	/**
@@ -83,13 +86,14 @@ public class CommandLineHelpGenerator {
 	 * @param metadata the initializr metadata
 	 * @param serviceUrl the service URL
 	 * @return the generic capabilities text document
+	 * @throws IOException if rendering the capabilities failed
 	 */
 	public String generateHttpieCapabilities(InitializrMetadata metadata,
-			String serviceUrl) {
+			String serviceUrl) throws IOException {
 		Map<String, Object> model = initializeCommandLineModel(metadata, serviceUrl);
-		model.put("examples", this.template.process("httpie-examples.txt", model));
+		model.put("examples", this.template.render("cli/httpie-examples", model));
 		model.put("hasExamples", true);
-		return this.template.process("cli-capabilities.txt", model);
+		return this.template.render("cli/cli-capabilities", model);
 	}
 
 	/**
@@ -98,12 +102,13 @@ public class CommandLineHelpGenerator {
 	 * @param metadata the initializr metadata
 	 * @param serviceUrl the service URL
 	 * @return the generic capabilities text document
+	 * @throws IOException if rendering the capabilities failed
 	 */
 	public String generateSpringBootCliCapabilities(InitializrMetadata metadata,
-			String serviceUrl) {
+			String serviceUrl) throws IOException {
 		Map<String, Object> model = initializeSpringBootCliModel(metadata, serviceUrl);
 		model.put("hasExamples", false);
-		return this.template.process("boot-cli-capabilities.txt", model);
+		return this.template.render("cli/boot-cli-capabilities", model);
 	}
 
 	protected Map<String, Object> initializeCommandLineModel(InitializrMetadata metadata,

initializr-web/src/test/java/io/spring/initializr/web/autoconfigure/InitializrAutoConfigurationTests.java

@@ -16,9 +16,9 @@
 
 package io.spring.initializr.web.autoconfigure;
 
+import io.spring.initializr.generator.io.template.TemplateRenderer;
 import io.spring.initializr.metadata.DependencyMetadataProvider;
 import io.spring.initializr.metadata.InitializrMetadataProvider;
-import io.spring.initializr.util.TemplateRenderer;
 import io.spring.initializr.web.ProjectResourceLocator;
 import io.spring.initializr.web.project.MainController;
 import io.spring.initializr.web.project.ProjectGenerationInvoker;

initializr-web/src/test/java/io/spring/initializr/web/project/CommandLineExampleIntegrationTests.java

@@ -26,8 +26,8 @@ import org.springframework.test.context.ActiveProfiles;
 /**
  * Validate that the "raw" HTTP commands that are described in the command-line help
  * works. If anything needs to be updated here, please double check the
- * "curl-examples.txt" as it may need an update as well. This is also a good indicator of
+ * "cli/curl-examples.mustache" as it may need an update as well. This is also a good
- * a non backward compatible change.
+ * indicator of a non backward compatible change.
  *
  * @author Stephane Nicoll
  */

initializr-web/src/test/java/io/spring/initializr/web/support/CommandLineHelpGeneratorTests.java

@@ -16,19 +16,22 @@
 
 package io.spring.initializr.web.support;
 
+import java.io.IOException;
 import java.util.Arrays;
 
+import io.spring.initializr.generator.io.template.MustacheTemplateRenderer;
 import io.spring.initializr.generator.spring.test.InitializrMetadataTestBuilder;
 import io.spring.initializr.metadata.Dependency;
 import io.spring.initializr.metadata.InitializrMetadata;
 import io.spring.initializr.metadata.Type;
-import io.spring.initializr.util.TemplateRenderer;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
+ * Tests for {@link CommandLineHelpGenerator}.
+ *
  * @author Stephane Nicoll
  */
 class CommandLineHelpGeneratorTests {
@@ -37,11 +40,12 @@ class CommandLineHelpGeneratorTests {
 
 	@BeforeEach
 	public void init() {
-		this.generator = new CommandLineHelpGenerator(new TemplateRenderer());
+		this.generator = new CommandLineHelpGenerator(
+				new MustacheTemplateRenderer("classpath:/templates"));
 	}
 
 	@Test
-	void generateGenericCapabilities() {
+	void generateGenericCapabilities() throws IOException {
 		InitializrMetadata metadata = InitializrMetadataTestBuilder.withDefaults()
 				.addDependencyGroup("test", createDependency("id-b", "depB"),
 						createDependency("id-a", "depA", "and some description"))
@@ -57,7 +61,7 @@ class CommandLineHelpGeneratorTests {
 	}
 
 	@Test
-	void generateCapabilitiesWithTypeDescription() {
+	void generateCapabilitiesWithTypeDescription() throws IOException {
 		Type type = new Type();
 		type.setId("foo");
 		type.setName("foo-name");
@@ -72,7 +76,7 @@ class CommandLineHelpGeneratorTests {
 	}
 
 	@Test
-	void generateCapabilitiesWithAlias() {
+	void generateCapabilitiesWithAlias() throws IOException {
 		Dependency dependency = createDependency("dep", "some description");
 		dependency.setAliases(Arrays.asList("legacy", "another"));
 		InitializrMetadata metadata = InitializrMetadataTestBuilder.withDefaults()
@@ -85,7 +89,7 @@ class CommandLineHelpGeneratorTests {
 	}
 
 	@Test
-	void generateCurlCapabilities() {
+	void generateCurlCapabilities() throws IOException {
 		InitializrMetadata metadata = InitializrMetadataTestBuilder.withDefaults()
 				.addDependencyGroup("test", createDependency("id-b", "depB"),
 						createDependency("id-a", "depA", "and some description"))
@@ -101,7 +105,7 @@ class CommandLineHelpGeneratorTests {
 	}
 
 	@Test
-	void generateHttpCapabilities() {
+	void generateHttpCapabilities() throws IOException {
 		InitializrMetadata metadata = InitializrMetadataTestBuilder.withDefaults()
 				.addDependencyGroup("test", createDependency("id-b", "depB"),
 						createDependency("id-a", "depA", "and some description"))
@@ -118,7 +122,7 @@ class CommandLineHelpGeneratorTests {
 	}
 
 	@Test
-	void generateSpringBootCliCapabilities() {
+	void generateSpringBootCliCapabilities() throws IOException {
 		InitializrMetadata metadata = InitializrMetadataTestBuilder.withDefaults()
 				.addDependencyGroup("test", createDependency("id-b", "depB"),
 						createDependency("id-a", "depA", "and some description"))
@@ -139,7 +143,7 @@ class CommandLineHelpGeneratorTests {
 	}
 
 	@Test
-	void generateCapabilitiesWithVersionRange() {
+	void generateCapabilitiesWithVersionRange() throws IOException {
 		Dependency first = Dependency.withId("first");
 		first.setDescription("first desc");
 		first.setVersionRange("1.2.0.RELEASE");