[kotlin][client] fix encoding of individual parts of a multipart request

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/KotlinClientCodegen.java

@@ -705,6 +705,7 @@ private void processMultiplatformLibrary(final String infrastructureFolder) {
     private void commonJvmMultiplatformSupportingFiles(String infrastructureFolder) {
         supportingFiles.add(new SupportingFile("infrastructure/ApiClient.kt.mustache", infrastructureFolder, "ApiClient.kt"));
         supportingFiles.add(new SupportingFile("infrastructure/ApiAbstractions.kt.mustache", infrastructureFolder, "ApiAbstractions.kt"));
+        supportingFiles.add(new SupportingFile("infrastructure/PartConfig.kt.mustache", infrastructureFolder, "PartConfig.kt"));
         supportingFiles.add(new SupportingFile("infrastructure/RequestConfig.kt.mustache", infrastructureFolder, "RequestConfig.kt"));
         supportingFiles.add(new SupportingFile("infrastructure/RequestMethod.kt.mustache", infrastructureFolder, "RequestMethod.kt"));
     }

modules/openapi-generator/src/main/resources/kotlin-client/infrastructure/PartConfig.kt.mustache

@@ -0,0 +1,11 @@
+package {{packageName}}.infrastructure
+
+/**
+ * Defines a config object for a given part of a multi-part request.
+ * NOTE: Headers is a Map<String,String> because rfc2616 defines
+ *       multi-valued headers as csv-only.
+ */
+{{#nonPublicApi}}internal {{/nonPublicApi}}data class PartConfig<T>(
+    val headers: MutableMap<String, String> = mutableMapOf(),
+    val body: T? = null
+)

modules/openapi-generator/src/main/resources/kotlin-client/libraries/jvm-okhttp/api.mustache

@@ -38,6 +38,7 @@ import {{packageName}}.infrastructure.ClientError
 import {{packageName}}.infrastructure.ServerException
 import {{packageName}}.infrastructure.ServerError
 import {{packageName}}.infrastructure.MultiValueMap
+import {{packageName}}.infrastructure.PartConfig
 import {{packageName}}.infrastructure.RequestConfig
 import {{packageName}}.infrastructure.RequestMethod
 import {{packageName}}.infrastructure.ResponseType
@@ -169,7 +170,7 @@ import {{packageName}}.infrastructure.toMultiValue
         {{/isDeprecated}}
         val localVariableConfig = {{operationId}}RequestConfig({{#allParams}}{{{paramName}}} = {{{paramName}}}{{^-last}}, {{/-last}}{{/allParams}})
 
-        return{{^doNotUseRxAndCoroutines}}{{#useCoroutines}}@withContext{{/useCoroutines}}{{/doNotUseRxAndCoroutines}} request<{{#hasBodyParam}}{{#bodyParams}}{{{dataType}}}{{/bodyParams}}{{/hasBodyParam}}{{^hasBodyParam}}{{^hasFormParams}}Unit{{/hasFormParams}}{{#hasFormParams}}Map<String, Any?>{{/hasFormParams}}{{/hasBodyParam}}, {{{returnType}}}{{^returnType}}Unit{{/returnType}}>(
+        return{{^doNotUseRxAndCoroutines}}{{#useCoroutines}}@withContext{{/useCoroutines}}{{/doNotUseRxAndCoroutines}} request<{{#hasBodyParam}}{{#bodyParams}}{{{dataType}}}{{/bodyParams}}{{/hasBodyParam}}{{^hasBodyParam}}{{^hasFormParams}}Unit{{/hasFormParams}}{{#hasFormParams}}Map<String, PartConfig<*>>{{/hasFormParams}}{{/hasBodyParam}}, {{{returnType}}}{{^returnType}}Unit{{/returnType}}>(
             localVariableConfig
         )
     }
@@ -183,8 +184,14 @@ import {{packageName}}.infrastructure.toMultiValue
     {{#isDeprecated}}
     @Deprecated(message = "This operation is deprecated.")
     {{/isDeprecated}}
-    fun {{operationId}}RequestConfig({{#allParams}}{{{paramName}}}: {{#isEnum}}{{#isContainer}}kotlin.collections.List<{{enumName}}_{{operationId}}>{{/isContainer}}{{^isContainer}}{{enumName}}_{{operationId}}{{/isContainer}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{/isEnum}}{{^required}}?{{/required}}{{^-last}}, {{/-last}}{{/allParams}}) : RequestConfig<{{#hasBodyParam}}{{#bodyParams}}{{{dataType}}}{{/bodyParams}}{{/hasBodyParam}}{{^hasBodyParam}}{{^hasFormParams}}Unit{{/hasFormParams}}{{#hasFormParams}}Map<String, Any?>{{/hasFormParams}}{{/hasBodyParam}}> {
-        val localVariableBody = {{#hasBodyParam}}{{#bodyParams}}{{{paramName}}}{{/bodyParams}}{{/hasBodyParam}}{{^hasBodyParam}}{{^hasFormParams}}null{{/hasFormParams}}{{#hasFormParams}}mapOf({{#formParams}}"{{{baseName}}}" to {{{paramName}}}{{^-last}}, {{/-last}}{{/formParams}}){{/hasFormParams}}{{/hasBodyParam}}
+    fun {{operationId}}RequestConfig({{#allParams}}{{{paramName}}}: {{#isEnum}}{{#isContainer}}kotlin.collections.List<{{enumName}}_{{operationId}}>{{/isContainer}}{{^isContainer}}{{enumName}}_{{operationId}}{{/isContainer}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{/isEnum}}{{^required}}?{{/required}}{{^-last}}, {{/-last}}{{/allParams}}) : RequestConfig<{{#hasBodyParam}}{{#bodyParams}}{{{dataType}}}{{/bodyParams}}{{/hasBodyParam}}{{^hasBodyParam}}{{^hasFormParams}}Unit{{/hasFormParams}}{{#hasFormParams}}Map<String, PartConfig<*>>{{/hasFormParams}}{{/hasBodyParam}}> {
+        val localVariableBody = {{#hasBodyParam}}{{!
+          }}{{#bodyParams}}{{{paramName}}}{{/bodyParams}}{{/hasBodyParam}}{{^hasBodyParam}}{{!
+          }}{{^hasFormParams}}null{{/hasFormParams}}{{!
+          }}{{#hasFormParams}}mapOf({{#formParams}}
+            "{{{baseName}}}" to PartConfig(body = {{{paramName}}}, headers = mutableMapOf({{#contentType}}"Content-Type" to "{{contentType}}"{{/contentType}})),{{!
+            }}{{/formParams}}){{/hasFormParams}}{{!
+        }}{{/hasBodyParam}}
         val localVariableQuery: MultiValueMap = {{^hasQueryParams}}mutableMapOf()
 {{/hasQueryParams}}{{#hasQueryParams}}mutableMapOf<kotlin.String, kotlin.collections.List<kotlin.String>>()
             .apply {

modules/openapi-generator/src/main/resources/kotlin-client/libraries/jvm-okhttp/infrastructure/ApiClient.kt.mustache

@@ -25,6 +25,9 @@ import okhttp3.MediaType.Companion.toMediaTypeOrNull
 {{/jvm-okhttp4}}
 import okhttp3.Request
 import okhttp3.Headers
+{{#jvm-okhttp4}}
+import okhttp3.Headers.Companion.toHeaders
+{{/jvm-okhttp4}}
 import okhttp3.MultipartBody
 import okhttp3.Call
 import okhttp3.Callback
@@ -111,78 +114,62 @@ import com.squareup.moshi.adapter
         return contentType ?: "application/octet-stream"
     }
 
-    protected inline fun <reified T> requestBody(content: T, mediaType: String = JsonMediaType): RequestBody =
+    protected inline fun <reified T> requestBody(content: T, mediaType: String?): RequestBody =
         when {
-            {{#jvm-okhttp3}}
-            content is File -> RequestBody.create(MediaType.parse(mediaType), content)
-            {{/jvm-okhttp3}}
-            {{#jvm-okhttp4}}
-            content is File -> content.asRequestBody(mediaType.toMediaTypeOrNull())
-            {{/jvm-okhttp4}}
-            mediaType == FormDataMediaType -> {
+            mediaType == FormDataMediaType ->
                 MultipartBody.Builder()
                     .setType(MultipartBody.FORM)
                     .apply {
-                        // content's type *must* be Map<String, Any?>
+                        // content's type *must* be Map<String, PartConfig<*>>
                         @Suppress("UNCHECKED_CAST")
-                        (content as Map<String, Any?>).forEach { (key, value) ->
-                            if (value is File) {
-                                val partHeaders = Headers.{{#jvm-okhttp3}}of{{/jvm-okhttp3}}{{#jvm-okhttp4}}headersOf{{/jvm-okhttp4}}(
-                                    "Content-Disposition",
-                                    "form-data; name=\"$key\"; filename=\"${value.name}\""
-                                )
-                                {{#jvm-okhttp3}}
-                                val fileMediaType = MediaType.parse(guessContentTypeFromFile(value))
-                                addPart(partHeaders, RequestBody.create(fileMediaType, value))
-                                {{/jvm-okhttp3}}
-                                {{#jvm-okhttp4}}
-                                val fileMediaType = guessContentTypeFromFile(value).toMediaTypeOrNull()
-                                addPart(partHeaders, value.asRequestBody(fileMediaType))
-                                {{/jvm-okhttp4}}
-                            } else {
-                                val partHeaders = Headers.{{#jvm-okhttp3}}of{{/jvm-okhttp3}}{{#jvm-okhttp4}}headersOf{{/jvm-okhttp4}}(
-                                    "Content-Disposition",
-                                    "form-data; name=\"$key\""
-                                )
-                                addPart(
-                                    partHeaders,
-                                    {{#jvm-okhttp3}}
-                                    RequestBody.create(null, parameterToString(value))
-                                    {{/jvm-okhttp3}}
-                                    {{#jvm-okhttp4}}
-                                    parameterToString(value).toRequestBody(null)
-                                    {{/jvm-okhttp4}}
-                                )
+                        (content as Map<String, PartConfig<*>>).forEach { (name, part) ->
+                            val contentType = part.headers.remove("Content-Type")
+                            val bodies = if (part.body is Iterable<*>) part.body else listOf(part.body)
+                            bodies.forEach { body ->
+                                val headers = part.headers.toMutableMap() +
+                                    ("Content-Disposition" to "form-data; name=\"$name\"" + if (body is File) "; filename=\"${body.name}\"" else "")
+                                addPart({{#jvm-okhttp3}}Headers.of(headers){{/jvm-okhttp3}}{{#jvm-okhttp4}}headers.toHeaders(){{/jvm-okhttp4}},
+                                    requestSingleBody(body, contentType))
                             }
                         }
                     }.build()
-            }
+            else -> requestSingleBody(content, mediaType)
+        }
+
+    protected inline fun <reified T> requestSingleBody(content: T, mediaType: String?): RequestBody =
+        when {
+            {{#jvm-okhttp3}}
+            content is File -> RequestBody.create(MediaType.parse(mediaType ?: guessContentTypeFromFile(content)), content)
+            {{/jvm-okhttp3}}
+            {{#jvm-okhttp4}}
+            content is File -> content.asRequestBody((mediaType ?: guessContentTypeFromFile(content)).toMediaTypeOrNull())
+            {{/jvm-okhttp4}}
             mediaType == FormUrlEncMediaType -> {
                 FormBody.Builder().apply {
-                    // content's type *must* be Map<String, Any?>
+                    // content's type *must* be Map<String, PartConfig<*>>
                     @Suppress("UNCHECKED_CAST")
-                    (content as Map<String, Any?>).forEach { (key, value) ->
-                        add(key, parameterToString(value))
+                    (content as Map<String, PartConfig<*>>).forEach { (name, part) ->
+                        add(name, parameterToString(part.body))
                     }
                 }.build()
             }
-            mediaType.startsWith("application/") && mediaType.endsWith("json") ->
+            mediaType == null || mediaType.startsWith("application/") && mediaType.endsWith("json") ->
             {{#jvm-okhttp3}}
                 if (content == null) {
                     EMPTY_REQUEST
                 } else {
                     RequestBody.create(
                         {{#moshi}}
-                        MediaType.parse(mediaType), Serializer.moshi.adapter(T::class.java).toJson(content)
+                        MediaType.parse(mediaType ?: JsonMediaType), Serializer.moshi.adapter(T::class.java).toJson(content)
                         {{/moshi}}
                         {{#gson}}
-                        MediaType.parse(mediaType), Serializer.gson.toJson(content, T::class.java)
+                        MediaType.parse(mediaType ?: JsonMediaType), Serializer.gson.toJson(content, T::class.java)
                         {{/gson}}
                         {{#jackson}}
-                        MediaType.parse(mediaType), Serializer.jacksonObjectMapper.writeValueAsString(content)
+                        MediaType.parse(mediaType ?: JsonMediaType), Serializer.jacksonObjectMapper.writeValueAsString(content)
                         {{/jackson}}
                         {{#kotlinx_serialization}}
-                        MediaType.parse(mediaType), Serializer.jvmJson.encodeToString(content)
+                        MediaType.parse(mediaType ?: JsonMediaType), Serializer.jvmJson.encodeToString(content)
                         {{/kotlinx_serialization}}
                     )
                 }
@@ -203,9 +190,7 @@ import com.squareup.moshi.adapter
                     {{#kotlinx_serialization}}
                     Serializer.jvmJson.encodeToString(content)
                     {{/kotlinx_serialization}}
-                        .toRequestBody(
-                            mediaType.toMediaTypeOrNull()
-                        )
+                        .toRequestBody((mediaType ?: JsonMediaType).toMediaTypeOrNull())
                 }
             {{/jvm-okhttp4}}
             mediaType == XmlMediaType -> throw UnsupportedOperationException("xml not currently supported.")
@@ -220,10 +205,6 @@ import com.squareup.moshi.adapter
         if(body == null) {
             return null
         }
-        val bodyContent = body.string()
-        if (bodyContent.isEmpty()) {
-            return null
-        }
         if (T::class.java == File::class.java) {
             // return tempfile
             {{^supportAndroidApiLevel25AndBelow}}
@@ -239,14 +220,19 @@ import com.squareup.moshi.adapter
             }
             {{/supportAndroidApiLevel25AndBelow}}
             f.deleteOnExit()
-            val out = BufferedWriter(FileWriter(f))
-            out.write(bodyContent)
-            out.close()
+            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
             return f as T
         }
+        val bodyContent = body.string()
+        if (bodyContent.isEmpty()) {
+            return null
+        }
         return when {
-        mediaType==null || (mediaType.startsWith("application/") && mediaType.endsWith("json")) ->
-                {{#moshi}}Serializer.moshi.adapter<T>().fromJson(bodyContent){{/moshi}}{{#gson}}Serializer.gson.fromJson(bodyContent, (object: TypeToken<T>(){}).getType()){{/gson}}{{#jackson}}Serializer.jacksonObjectMapper.readValue(bodyContent, object: TypeReference<T>() {}){{/jackson}}{{#kotlinx_serialization}}Serializer.jvmJson.decodeFromString<T>(bodyContent){{/kotlinx_serialization}}
+            mediaType==null || (mediaType.startsWith("application/") && mediaType.endsWith("json")) ->
+                {{#moshi}}Serializer.moshi.adapter<T>().fromJson(bodyContent){{/moshi}}{{!
+                }}{{#gson}}Serializer.gson.fromJson(bodyContent, (object: TypeToken<T>(){}).getType()){{/gson}}{{!
+                }}{{#jackson}}Serializer.jacksonObjectMapper.readValue(bodyContent, object: TypeReference<T>() {}){{/jackson}}{{!
+                }}{{#kotlinx_serialization}}Serializer.jvmJson.decodeFromString<T>(bodyContent){{/kotlinx_serialization}}
             else ->  throw UnsupportedOperationException("responseBody currently only supports JSON body.")
         }
     }

modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultGeneratorTest.java

@@ -460,7 +460,7 @@ public void testBuiltinLibraryTemplates() throws IOException {
 
             List<File> files = generator.opts(clientOptInput).generate();
 
-            Assert.assertEquals(files.size(), 26);
+            Assert.assertEquals(files.size(), 27);
 
             // Generator should report a library templated file as a generated file
             TestUtils.ensureContainsFile(files, output, "src/main/kotlin/org/openapitools/client/infrastructure/Errors.kt");
@@ -502,7 +502,7 @@ public void testBuiltinNonLibraryTemplates() throws IOException {
 
             List<File> files = generator.opts(clientOptInput).generate();
 
-            Assert.assertEquals(files.size(), 26);
+            Assert.assertEquals(files.size(), 27);
 
             // Generator should report README.md as a generated file
             TestUtils.ensureContainsFile(files, output, "README.md");
@@ -567,7 +567,7 @@ public void testCustomLibraryTemplates() throws IOException {
 
             List<File> files = generator.opts(clientOptInput).generate();
 
-            Assert.assertEquals(files.size(), 26);
+            Assert.assertEquals(files.size(), 27);
 
             // Generator should report a library templated file as a generated file
             TestUtils.ensureContainsFile(files, output, "src/main/kotlin/org/openapitools/client/infrastructure/Errors.kt");
@@ -621,7 +621,7 @@ public void testCustomNonLibraryTemplates() throws IOException {
 
             List<File> files = generator.opts(clientOptInput).generate();
 
-            Assert.assertEquals(files.size(), 26);
+            Assert.assertEquals(files.size(), 27);
 
             // Generator should report README.md as a generated file
             TestUtils.ensureContainsFile(files, output, "README.md");

samples/client/petstore/kotlin-array-simple-string/.openapi-generator/FILES

@@ -17,6 +17,7 @@ src/main/kotlin/org/openapitools/client/infrastructure/Errors.kt
 src/main/kotlin/org/openapitools/client/infrastructure/LocalDateAdapter.kt
 src/main/kotlin/org/openapitools/client/infrastructure/LocalDateTimeAdapter.kt
 src/main/kotlin/org/openapitools/client/infrastructure/OffsetDateTimeAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/PartConfig.kt
 src/main/kotlin/org/openapitools/client/infrastructure/RequestConfig.kt
 src/main/kotlin/org/openapitools/client/infrastructure/RequestMethod.kt
 src/main/kotlin/org/openapitools/client/infrastructure/ResponseExtensions.kt

samples/client/petstore/kotlin-array-simple-string/src/main/kotlin/org/openapitools/client/apis/DefaultApi.kt

@@ -32,6 +32,7 @@ import org.openapitools.client.infrastructure.ClientError
 import org.openapitools.client.infrastructure.ServerException
 import org.openapitools.client.infrastructure.ServerError
 import org.openapitools.client.infrastructure.MultiValueMap
+import org.openapitools.client.infrastructure.PartConfig
 import org.openapitools.client.infrastructure.RequestConfig
 import org.openapitools.client.infrastructure.RequestMethod
 import org.openapitools.client.infrastructure.ResponseType