Kotlin Coroutines Support

plugin/src/main/java/com/yelp/codegen/KotlinCoroutineGenerator.kt

@@ -0,0 +1,14 @@
+package com.yelp.codegen
+
+open class KotlinCoroutineGenerator : KotlinGenerator() {
+
+    init {
+        templateDir = "kotlin-coroutines"
+    }
+
+    override fun getName() = "kotlin-coroutines"
+
+    override fun wrapResponseType(imports: MutableSet<String>, responsePrimitiveType: String) = responsePrimitiveType
+
+    override fun getNoResponseType(imports: MutableSet<String>) = "Unit"
+}

plugin/src/main/java/com/yelp/codegen/KotlinGenerator.kt

@@ -20,7 +20,7 @@ import io.swagger.models.Swagger
 import io.swagger.models.properties.Property
 import java.io.File
 
-class KotlinGenerator : SharedCodegen() {
+open class KotlinGenerator : SharedCodegen() {
 
     companion object {
         /**
@@ -377,19 +377,16 @@ class KotlinGenerator : SharedCodegen() {
             }
         }
 
-        when {
+        codegenOperation.returnType = when {
             codegenOperation.isResponseFile -> {
-                codegenOperation.returnType = "Single<ResponseBody>"
                 codegenOperation.imports.add("okhttp3.ResponseBody")
-                codegenOperation.imports.add("io.reactivex.Single")
+                wrapResponseType(codegenOperation.imports, "ResponseBody")
             }
             codegenOperation.returnType == null -> {
-                codegenOperation.returnType = "Completable"
-                codegenOperation.imports.add("io.reactivex.Completable")
+                getNoResponseType(codegenOperation.imports)
             }
             else -> {
-                codegenOperation.returnType = "Single<${codegenOperation.returnType}>"
-                codegenOperation.imports.add("io.reactivex.Single")
+                wrapResponseType(codegenOperation.imports, codegenOperation.returnType)
             }
         }
 
@@ -425,4 +422,22 @@ class KotlinGenerator : SharedCodegen() {
         // Override the swagger version with the one provided from command line.
         swagger.info.version = additionalProperties[SPEC_VERSION] as String
     }
+
+    /**
+     * Wraps the return type of an operation with the proper type (e.g. Single, Observable, Future, etc.)
+     * Use this method to eventually add imports if needed in the [imports] param.
+     */
+    protected open fun wrapResponseType(imports: MutableSet<String>, responsePrimitiveType: String): String {
+        imports.add("io.reactivex.Single")
+        return "Single<$responsePrimitiveType>"
+    }
+
+    /**
+     * Get the return type of operations with no ResponseType set (void, Unit, Completables).
+     * Use this method to eventually add imports if needed in the [imports] param.
+     */
+    protected open fun getNoResponseType(imports: MutableSet<String>): String {
+        imports.add("io.reactivex.Completable")
+        return "Completable"
+    }
 }

plugin/src/main/java/com/yelp/codegen/Main.kt

@@ -69,6 +69,7 @@ fun main(args: Array<String>) {
     configurator.outputDir = parsed['o']
 
     configurator.addAdditionalProperty(LANGUAGE, parsed['p'])
+
     configurator.addAdditionalProperty(SPEC_VERSION, specVersion)
     configurator.addAdditionalProperty(SERVICE_NAME, parsed['s'])
     configurator.addAdditionalProperty(GROUP_ID, parsed['g'])

plugin/src/main/resources/META-INF/services/io.swagger.codegen.CodegenConfig

@@ -1 +1,2 @@
 com.yelp.codegen.KotlinGenerator
+com.yelp.codegen.KotlinCoroutineGenerator

plugin/src/main/resources/kotlin-coroutines/data_class.mustache

@@ -0,0 +1,23 @@
+/**
+ * {{{description}}}
+{{#vars}}
+ * @property {{{name}}} {{description}}
+{{/vars}}
+ */
+{{#hasVars}}data {{/hasVars}}class {{classname}} {{#hasVars}}(
+{{#requiredVars}}
+{{>data_class_req_var}}{{^-last}},
+{{/-last}}{{/requiredVars}}{{#hasRequired}}{{#hasOptional}},
+{{/hasOptional}}{{/hasRequired}}{{#optionalVars}}{{>data_class_opt_var}}{{^-last}},
+{{/-last}}{{/optionalVars}}
+){{#hasEnums}} {
+{{#vars}}
+{{#isEnum}}
+    /**
+     * {{{description}}}
+     * Values: {{#allowableValues}}{{#enumVars}}{{&name}}{{^-last}}, {{/-last}}{{/enumVars}}{{/allowableValues}}
+     */
+    enum class {{enumName}}(val value: {{complexType}}){ {{#allowableValues}}{{#enumVars}}
+        @Json(name = {{{value}}}) {{&name}}({{{value}}}){{^-last}},{{/-last}}{{#-last}}{{/-last}}{{/enumVars}}{{/allowableValues}}
+    }
+{{/isEnum}}{{/vars}}}{{/hasEnums}}{{/hasVars}}

plugin/src/main/resources/kotlin-coroutines/data_class_opt_var.mustache

@@ -0,0 +1 @@
+        @Json(name = "{{{baseName}}}") @field:Json(name = "{{{baseName}}}") {{#vendorExtensions.x-nullable}}@XNullable {{/vendorExtensions.x-nullable}}var {{{name}}}: {{#isEnum}}{{{datatypeWithEnum}}}{{/isEnum}}{{^isEnum}}{{{datatype}}}{{/isEnum}} = {{#defaultvalue}}{{defaultvalue}}{{/defaultvalue}}{{^defaultvalue}}null{{/defaultvalue}}

plugin/src/main/resources/kotlin-coroutines/data_class_req_var.mustache

@@ -0,0 +1 @@
+        @Json(name = "{{{baseName}}}") @field:Json(name = "{{{baseName}}}") var {{{name}}}: {{#isEnum}}{{{datatypeWithEnum}}}{{/isEnum}}{{^isEnum}}{{{datatype}}}{{/isEnum}}

plugin/src/main/resources/kotlin-coroutines/enum_class.mustache

@@ -0,0 +1,7 @@
+/**
+* {{{description}}}
+* Values: {{#allowableValues}}{{#enumVars}}{{&name}}{{^-last}},{{/-last}}{{/enumVars}}{{/allowableValues}}
+*/
+enum class {{classname}}(val value: {{dataType}}){
+{{#allowableValues}}{{#enumVars}}    @Json(name = {{{value}}}) {{&name}}({{{value}}}){{^-last}},{{/-last}}
+{{/enumVars}}{{/allowableValues}}}

plugin/src/main/resources/kotlin-coroutines/file_header.mustache

@@ -0,0 +1,5 @@
+/**
+ * NOTE: This class is auto generated by the Swagger Gradle Codegen for the following API: {{{appName}}}
+ *
+ * More info on this tool is available on https://github.com/Yelp/swagger-gradle-codegen
+ */

plugin/src/main/resources/kotlin-coroutines/model.mustache

@@ -0,0 +1,11 @@
+{{>file_header}}
+package {{modelPackage}}
+
+{{#imports}}import {{import}}
+{{/imports}}
+
+{{#models}}
+{{#model}}
+{{#isAlias}}{{>type_alias}}{{/isAlias}}{{^isAlias}}{{#isEnum}}{{>enum_class}}{{/isEnum}}{{^isEnum}}{{>data_class}}{{/isEnum}}{{/isAlias}}
+{{/model}}
+{{/models}}

plugin/src/main/resources/kotlin-coroutines/retrofit2/api.mustache

@@ -0,0 +1,54 @@
+{{>file_header}}
+package {{package}}
+
+import okhttp3.RequestBody
+
+{{#imports}}import {{import}}
+{{/imports}}
+
+{{#operations}}
+@JvmSuppressWildcards
+interface {{classname}} {
+  {{#operation}}
+  /**{{#summary}} {{{newline}}}   * {{{summary}}}{{/summary}}{{#notes}}{{{newline}}}   * {{{<br/>}}}{{{notes}}}{{/notes}}
+   * The endpoint is owned by {{{vendorExtensions.x-team-owners}}}{{^vendorExtensions.x-team-owners}}{{service_name}} service owner{{/vendorExtensions.x-team-owners}}
+{{#allParams}}
+   * @param {{paramName}} {{description}}{{#required}} (required){{/required}}{{^required}} (optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}
+{{/allParams}}
+{{#externalDocs}}
+   * {{description}}
+   * @see [{{url}}"][{{summary}} Documentation]
+{{/externalDocs}}
+   */
+  {{#formParams}}
+  {{#-first}}
+  {{#isMultipart}}@retrofit2.http.Multipart{{/isMultipart}}{{^isMultipart}}@retrofit2.http.FormUrlEncoded{{/isMultipart}}
+  {{/-first}}
+  {{/formParams}}
+  {{^formParams}}
+  {{#prioritizedContentTypes}}
+  {{#-first}}
+  @Headers({
+    "Content-Type:{{{mediaType}}}"
+  })
+  {{/-first}}
+  {{/prioritizedContentTypes}}
+  {{/formParams}}
+  @Headers({{#vendorExtensions.x-operation-id}}{{{newline}}}    "X-Operation-ID: {{vendorExtensions.x-operation-id}}"{{/vendorExtensions.x-operation-id}}{{^formParams}}{{#prioritizedContentTypes}}{{#-first}},
+    "Content-Type:{{{mediaType}}}"{{/-first}}{{/prioritizedContentTypes}}{{/formParams}}
+  )
+
+  @{{httpMethod}}("{{{path}}}"){{#vendorExtensions.x-unsafe-operation}}{{#isDeprecated}}
+      @Deprecated(message = "Deprecated and unsafe to use"){{/isDeprecated}}{{^isDeprecated}}
+      @Deprecated(message = "Unsafe to use"){{/isDeprecated}}
+  {{/vendorExtensions.x-unsafe-operation}}{{^vendorExtensions.x-unsafe-operation}}{{#isDeprecated}}
+      @Deprecated(message = "Deprecated"){{/isDeprecated}}
+  {{/vendorExtensions.x-unsafe-operation}}
+  suspend fun {{operationId}}({{^allParams}}){{/allParams}}
+    {{#allParams}}{{>retrofit2/queryParams}}{{>retrofit2/pathParams}}{{>retrofit2/headerParams}}{{>retrofit2/bodyParams}}{{>retrofit2/formParams}}{{#hasMore}},
+    {{/hasMore}}{{^hasMore}}
+  ){{/hasMore}}{{/allParams}}: {{{returnType}}}
+
+  {{/operation}}
+}
+{{/operations}}

plugin/src/main/resources/kotlin-coroutines/retrofit2/bodyParams.mustache

@@ -0,0 +1 @@
+{{#isBodyParam}}@retrofit2.http.Body  {{paramName}}: {{{dataType}}}{{/isBodyParam}}

plugin/src/main/resources/kotlin-coroutines/retrofit2/formParams.mustache

@@ -0,0 +1 @@
+{{#isFormParam}}{{#notFile}}{{#isMultipart}}@retrofit2.http.Part{{/isMultipart}}{{^isMultipart}}@retrofit2.http.Field{{/isMultipart}}("{{baseName}}") {{paramName}}: {{{dataType}}}{{/notFile}}{{#isFile}}{{#isMultipart}}@retrofit2.http.Part{{/isMultipart}}{{^isMultipart}}@retrofit2.http.Field{{/isMultipart}}("{{baseName}}\"; filename=\"{{baseName}}") {{paramName}}:  RequestBody{{^required}}?{{/required}} {{/isFile}}{{/isFormParam}}

plugin/src/main/resources/kotlin-coroutines/retrofit2/headerParams.mustache

@@ -0,0 +1 @@
+{{#isHeaderParam}}@retrofit2.http.Header("{{baseName}}") {{paramName}}: {{{dataType}}}{{/isHeaderParam}}

plugin/src/main/resources/kotlin-coroutines/retrofit2/pathParams.mustache

@@ -0,0 +1 @@
+{{#isPathParam}}@retrofit2.http.Path("{{baseName}}") {{paramName}}: {{{dataType}}}{{/isPathParam}}

plugin/src/main/resources/kotlin-coroutines/retrofit2/queryParams.mustache

@@ -0,0 +1 @@
+{{#isQueryParam}}@retrofit2.http.Query("{{baseName}}") {{#collectionFormat}}{{^isCollectionFormatMulti}}@{{{collectionFormat.toUpperCase}}} {{/isCollectionFormatMulti}}{{/collectionFormat}}{{paramName}}: {{{dataType}}}{{/isQueryParam}}

plugin/src/main/resources/kotlin-coroutines/tools/CollectionFormatConverterFactory.kt.mustache

@@ -0,0 +1,32 @@
+package {{packageName}}.tools
+
+import retrofit2.Converter
+import retrofit2.Retrofit
+import java.lang.reflect.Type
+
+internal class CollectionFormatConverterFactory : Converter.Factory() {
+
+    override fun stringConverter(type: Type, annotations: Array<out Annotation>, retrofit: Retrofit): Converter<*, String>? {
+        val rawType = getRawType(type)
+        if (rawType == String::class.java || rawType == List::class.java)
+            annotations.forEach {
+                when (it) {
+                    is CSV -> return CollectionFormatConverter(",")
+                    is SSV -> return CollectionFormatConverter(" ")
+                    is TSV -> return CollectionFormatConverter("\t")
+                    is PIPES -> return CollectionFormatConverter("|")
+                }
+            }
+        return null
+    }
+
+    private class CollectionFormatConverter(private val separator: String) : Converter<Any, String> {
+        override fun convert(value: Any): String {
+            when (value) {
+                is String -> return value
+                is List<*> -> return value.joinToString(separator)
+            }
+            throw RuntimeException("Unsupported type")
+        }
+    }
+}

plugin/src/main/resources/kotlin-coroutines/tools/CollectionFormats.kt.mustache

@@ -0,0 +1,20 @@
+package {{packageName}}.tools
+
+@Target(AnnotationTarget.FIELD, AnnotationTarget.VALUE_PARAMETER)
+@Retention(AnnotationRetention.RUNTIME)
+annotation class CSV
+
+
+@Target(AnnotationTarget.FIELD, AnnotationTarget.VALUE_PARAMETER)
+@Retention(AnnotationRetention.RUNTIME)
+annotation class SSV
+
+
+@Target(AnnotationTarget.FIELD, AnnotationTarget.VALUE_PARAMETER)
+@Retention(AnnotationRetention.RUNTIME)
+annotation class TSV
+
+
+@Target(AnnotationTarget.FIELD, AnnotationTarget.VALUE_PARAMETER)
+@Retention(AnnotationRetention.RUNTIME)
+annotation class PIPES

plugin/src/main/resources/kotlin-coroutines/tools/EnumToValueConverterFactory.kt.mustache

@@ -0,0 +1,34 @@
+package {{packageName}}.tools
+
+import com.squareup.moshi.Json
+import retrofit2.Converter
+import retrofit2.Retrofit
+import java.lang.reflect.Type
+
+internal class EnumToValueConverterFactory : Converter.Factory() {
+
+    private val enumConverter = EnumToValueConverter()
+
+    override fun stringConverter(type: Type, annotations: Array<out Annotation>, retrofit: Retrofit): Converter<*, String>? {
+        return if (type is Class<*> && type.isEnum) {
+            enumConverter
+        } else {
+            null
+        }
+    }
+
+    internal class EnumToValueConverter : Converter<Any, String> {
+        override fun convert(enum: Any): String? {
+            val enumName = (enum as Enum<*>).name
+            val jsonAnnotation : Json? = enum.javaClass.getField(enumName).getAnnotation(Json::class.java)
+
+            // Checking if the Enum is annotated with @Json to get the name.
+            // If not, fallback to enum default (.toString())
+            return if (jsonAnnotation != null) {
+                jsonAnnotation.name
+            } else {
+                enum.toString()
+            }
+        }
+    }
+}

plugin/src/main/resources/kotlin-coroutines/tools/GeneratedCodeConverters.kt.mustache

@@ -0,0 +1,39 @@
+package {{packageName}}.tools
+
+import com.squareup.moshi.Moshi
+import com.squareup.moshi.kotlin.reflect.KotlinJsonAdapterFactory
+import retrofit2.Converter
+import retrofit2.converter.moshi.MoshiConverterFactory
+
+
+object GeneratedCodeConverters {
+    private val moshi = Moshi.Builder()
+            .add(XNullableAdapterFactory())
+            .add(KotlinJsonAdapterFactory())
+            .add(TypesAdapterFactory())
+            .build()
+
+    /**
+     * Creates everything needed for retrofit to make it work with the client lib, including a
+     * [Moshi] instance. If you want to use your own instance of moshi, use
+     * converterFactory(moshi) instead, and add [XNullableAdapterFactory], [KotlinJsonAdapterFactory] and
+     * [TypesAdapterFactory] to your moshi builder (in a similar way how we are instantiating the `moshi` field here).
+     */
+    @JvmStatic
+    fun converterFactory(): Converter.Factory {
+        return WrapperConverterFactory(
+                CollectionFormatConverterFactory(),
+                EnumToValueConverterFactory(),
+                MoshiConverterFactory.create(moshi)
+        )
+    }
+
+    @JvmStatic
+    fun converterFactory(moshi: Moshi): Converter.Factory {
+        return WrapperConverterFactory(
+                CollectionFormatConverterFactory(),
+                EnumToValueConverterFactory(),
+                MoshiConverterFactory.create(moshi)
+        )
+    }
+}