Add support for HTTPie

Closes gh-70

CHANGELOG.adoc

@@ -7,6 +7,7 @@ order.
 
 === Release 1.0.0 (In progress)
 
+* https://github.com/spring-io/initializr/issues/70[#70]: explicit support for HTTPie (similar to curl).
 * https://github.com/spring-io/initializr/issues/67[#67]: explicit support for curl by returning a text
 description of the service instead of the raw meta-data. curl users can still discover the json metadata
 by setting the appropriate Accept header.

initializr/src/main/groovy/io/spring/initializr/CommandLineHelpGenerator.groovy

@@ -57,6 +57,17 @@ class CommandLineHelpGenerator {
 		doGenerateCapabilities(model)
 	}
 
+	/**
+	 * Generate the capabilities of the service using "HTTPie" as a plain text
+	 * document.
+	 */
+	String generateHttpieCapabilities(InitializrMetadata metadata, String serviceUrl) {
+		def model = initializeModel(metadata, serviceUrl)
+		model['examples'] = template 'httpie-examples.txt', model
+		model['hasExamples'] = true
+		doGenerateCapabilities(model)
+	}
+
 	private doGenerateCapabilities(def model) {
 		template 'cli-capabilities.txt', model
 	}

initializr/src/main/groovy/io/spring/initializr/web/MainController.groovy

@@ -77,12 +77,15 @@ class MainController extends AbstractInitializrController {
 		def metadata = metadataProvider.get()
 
 		def builder = ResponseEntity.ok().contentType(MediaType.TEXT_PLAIN)
-		if (userAgent && userAgent.startsWith(WebConfig.CURL_USER_AGENT_PREFIX)) {
-			builder.body(commandLineHelpGenerator.generateCurlCapabilities(metadata,appUrl))
-		}
-		else {
-			builder.body(commandLineHelpGenerator.generateGenericCapabilities(metadata, appUrl))
+		if (userAgent) {
+			if (userAgent.startsWith(WebConfig.CURL_USER_AGENT_PREFIX)) {
+				return builder.body(commandLineHelpGenerator.generateCurlCapabilities(metadata, appUrl))
+			}
+			if (userAgent.startsWith(WebConfig.HTTPIE_USER_AGENT_PREFIX)) {
+				return builder.body(commandLineHelpGenerator.generateHttpieCapabilities(metadata, appUrl))
+			}
 		}
+		builder.body(commandLineHelpGenerator.generateGenericCapabilities(metadata, appUrl))
 	}
 
 	@RequestMapping(value = "/", produces = ["application/vnd.initializr.v2+json", "application/json"])

initializr/src/main/groovy/io/spring/initializr/web/WebConfig.groovy

@@ -37,6 +37,8 @@ class WebConfig extends WebMvcConfigurerAdapter {
 
 	static final String CURL_USER_AGENT_PREFIX = 'curl'
 
+	static final String HTTPIE_USER_AGENT_PREFIX = 'HTTPie'
+
 	@Override
 	public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
 		configurer.defaultContentTypeStrategy(new CommandLineContentNegotiationStrategy())
@@ -59,7 +61,7 @@ class WebConfig extends WebMvcConfigurerAdapter {
 			}
 			String userAgent = request.getHeader(HttpHeaders.USER_AGENT)
 			if (userAgent) {
-				if (userAgent.startsWith(CURL_USER_AGENT_PREFIX)) {
+				if (userAgent.startsWith(CURL_USER_AGENT_PREFIX) || userAgent.startsWith(HTTPIE_USER_AGENT_PREFIX)) {
 					return Collections.singletonList(MediaType.TEXT_PLAIN)
 				}
 			}

initializr/src/main/resources/templates/httpie-examples.txt

@@ -0,0 +1,13 @@
+To create a default project:
+	\$ http ${serviceUrl}/starter.zip -d
+
+To create a web project using Java 8:
+	\$ http ${serviceUrl}/starter.zip dependencies==web \\
+			javaVersion==1.8 -d
+
+To create a web/data-jpa gradle project unpacked:
+	\$ http ${serviceUrl}/starter.tgz dependencies==web,data-jpa \\
+		   type==gradle-project baseDir==my-dir | tar -xzvf -
+
+To generate a Maven POM with war packaging:
+	\$ http ${serviceUrl}/pom.xml packaging==war -o pom.xml

initializr/src/test/groovy/io/spring/initializr/CommandLineHelpGeneratorTest.groovy

@@ -65,6 +65,19 @@ class CommandLineHelpGeneratorTest {
 		assertThat content, containsString('curl')
 	}
 
+	@Test
+	void generateHttpCapabilities() {
+		def metadata = InitializrMetadataBuilder.withDefaults().addDependencyGroup("test",
+				createDependency('id-b', 'depB'),
+				createDependency('id-a', 'depA', 'and some description')).validateAndGet()
+		String content = generator.generateHttpieCapabilities(metadata, "https://fake-service")
+		assertThat content, containsString('id-a - depA: and some description')
+		assertThat content, containsString('id-b - depB')
+		assertThat content, containsString("https://fake-service")
+		assertThat content, containsString('Examples:')
+		assertThat content, not(containsString('curl'))
+		assertThat content, containsString("http https://fake-service")
+	}
 
 	private static def createDependency(String id, String name) {
 		createDependency(id, name, null)

initializr/src/test/groovy/io/spring/initializr/web/MainControllerIntegrationTests.groovy

@@ -182,6 +182,25 @@ class MainControllerIntegrationTests extends AbstractInitializrControllerIntegra
 		validateCurrentMetadata(response)
 	}
 
+	@Test
+	void httpieReceivesTextByDefault() {
+		ResponseEntity<String> response = invokeHome('HTTPie/0.8.0', "*/*")
+		validateHttpIeHelpContent(response)
+	}
+
+	@Test // make sure curl can still receive metadata with json
+	void httpieWithAcceptHeaderJson() {
+		ResponseEntity<String> response = invokeHome('HTTPie/0.8.0', "application/json")
+		validateContentType(response, CURRENT_METADATA_MEDIA_TYPE)
+		validateCurrentMetadata(new JSONObject(response.body))
+	}
+
+	@Test
+	void httpieWithAcceptHeaderTextPlain() {
+		ResponseEntity<String> response = invokeHome('HTTPie/0.8.0', "text/plain")
+		validateHttpIeHelpContent(response)
+	}
+
 	@Test
 	void unknownCliWithTextPlain() {
 		ResponseEntity<String> response = invokeHome(null, "text/plain")
@@ -212,6 +231,15 @@ class MainControllerIntegrationTests extends AbstractInitializrControllerIntegra
 				containsString("curl")))
 	}
 
+	private void validateHttpIeHelpContent(ResponseEntity<String> response) {
+		validateContentType(response, MediaType.TEXT_PLAIN)
+		assertThat(response.body, allOf(
+				containsString("Spring Initializr"),
+				containsString('Examples:'),
+				not(containsString("curl")),
+				containsString("http")))
+	}
+
 	private void validateGenericHelpContent(ResponseEntity<String> response) {
 		validateContentType(response, MediaType.TEXT_PLAIN)
 		assertThat(response.body, allOf(