feat: Add swagger to return in root path

- Create swagger by postman collection in https://www.apimatic.io/transformer/

Author: Rudge Ferreira

build.gradle

@@ -2,7 +2,7 @@ group 'io.realworld'
 version '1.0-SNAPSHOT'
 
 ext {
-    javalin_version = "2.4.0"
+    javalin_version = "2.6.0"
     jackson_version = "2.9.7"
     slf4j_version = "1.7.25"
     koin_version = "1.0.2"
@@ -13,6 +13,7 @@ ext {
     h2_version = "1.4.197"
     exposed_version = "0.11.1"
     slugify_version = "2.1.+"
+    swagger_version = "3.17.6"
 }
 
 buildscript {
@@ -49,6 +50,7 @@ dependencies {
     compile "com.h2database:h2:$h2_version"
     compile "org.jetbrains.exposed:exposed:$exposed_version"
     compile "com.github.slugify:slugify:$slugify_version"
+    compile "org.webjars:swagger-ui:$swagger_version"
 
     testCompile "junit:junit:$junit_version"
     testCompile "com.mashape.unirest:unirest-java:$unirest_version"

src/main/kotlin/io/realworld/app/App.kt

@@ -3,7 +3,7 @@ package io.realworld.app
 import io.realworld.app.config.AppConfig
 import org.h2.tools.Server
 
-fun main(args: Array<String>) {
+fun main() {
     Server.createWebServer().start()
     AppConfig().setup().start()
 }

src/main/kotlin/io/realworld/app/config/AppConfig.kt

@@ -20,26 +20,30 @@ class AppConfig : KoinComponent {
     private val router: Router by inject()
 
     fun setup(): Javalin {
-        StandAloneContext.startKoin(allModules,
-                KoinProperties(true, true))
+        StandAloneContext.startKoin(
+            allModules,
+            KoinProperties(true, true)
+        )
         return Javalin.create()
-                .also { app ->
-                    this.configureMapper()
-                    app.enableCorsForAllOrigins()
-                            .contextPath(getProperty("context"))
-                            .event(JavalinEvent.SERVER_STOPPING) {
-                                StandAloneContext.stopKoin()
-                            }
-                    authConfig.configure(app)
-                    router.register(app)
-                    ErrorExceptionMapping.register(app)
-                    app.port(getProperty("server_port"))
-                }
+            .also { app ->
+                this.configureMapper()
+                app.enableCorsForAllOrigins()
+                    .contextPath(getProperty("context"))
+                    .event(JavalinEvent.SERVER_STOPPING) {
+                        StandAloneContext.stopKoin()
+                    }
+                authConfig.configure(app)
+                router.register(app)
+                ErrorExceptionMapping.register(app)
+                app.port(getProperty("server_port"))
+                app.enableWebJars()
+            }
     }
 
     private fun configureMapper() {
         val dateFormat = SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'")
-        JavalinJackson.configure(jacksonObjectMapper()
+        JavalinJackson.configure(
+            jacksonObjectMapper()
                 .disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS)
                 .setDateFormat(dateFormat)
                 .configure(SerializationFeature.WRITE_DATES_WITH_ZONE_ID, true)

src/main/kotlin/io/realworld/app/web/Router.kt

@@ -6,6 +6,7 @@ import io.javalin.apibuilder.ApiBuilder.get
 import io.javalin.apibuilder.ApiBuilder.path
 import io.javalin.apibuilder.ApiBuilder.post
 import io.javalin.apibuilder.ApiBuilder.put
+import io.javalin.core.util.SwaggerRenderer
 import io.javalin.security.SecurityUtil.roles
 import io.realworld.app.config.Roles
 import io.realworld.app.web.controllers.ArticleController
@@ -15,11 +16,13 @@ import io.realworld.app.web.controllers.TagController
 import io.realworld.app.web.controllers.UserController
 import org.koin.standalone.KoinComponent
 
-class Router(private val userController: UserController,
-             private val profileController: ProfileController,
-             private val articleController: ArticleController,
-             private val commentController: CommentController,
-             private val tagController: TagController) : KoinComponent {
+class Router(
+    private val userController: UserController,
+    private val profileController: ProfileController,
+    private val articleController: ArticleController,
+    private val commentController: CommentController,
+    private val tagController: TagController
+) : KoinComponent {
 
     fun register(app: Javalin) {
         val rolesOptionalAuthenticated = roles(Roles.ANYONE, Roles.AUTHENTICATED)
@@ -61,6 +64,7 @@ class Router(private val userController: UserController,
             path("tags") {
                 get(tagController::get, rolesOptionalAuthenticated)
             }
+            get("", SwaggerRenderer("swagger/api.yaml"), rolesOptionalAuthenticated)
         }
     }
 }