[kotlin] support collection format multi (#5792)

* [kotlin] support collectionFormat:multi

Adds "multi" support to collections.

Also changes generic lists (List<T>) to arrays. Generic lists and nested
lists can be problematic and require customized json factories. The
previous implement appeared to work because the results in the test were
LinkedHashMap with count greather than 0. The functional test has been
updated to force serialization and verify the results.

* [kotlin] Regenerate sample

* [kotlin] Update model test for Array changes

modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/KotlinClientCodegen.java

@@ -125,16 +125,16 @@ public class KotlinClientCodegen extends DefaultCodegen implements CodegenConfig
         typeMapping.put("date-time", "java.time.LocalDateTime");
         typeMapping.put("date", "java.time.LocalDateTime");
         typeMapping.put("file", "java.io.File");
-        typeMapping.put("array", "kotlin.collections.List");
-        typeMapping.put("list", "kotlin.collections.List");
+        typeMapping.put("array", "kotlin.Array");
+        typeMapping.put("list", "kotlin.Array");
         typeMapping.put("map", "kotlin.collections.Map");
         typeMapping.put("object", "kotlin.Any");
         typeMapping.put("binary", "kotlin.Array<kotlin.Byte>");
         typeMapping.put("Date", "java.time.LocalDateTime");
         typeMapping.put("DateTime", "java.time.LocalDateTime");
 
-        instantiationTypes.put("array", "listOf");
-        instantiationTypes.put("list", "listOf");
+        instantiationTypes.put("array", "arrayOf");
+        instantiationTypes.put("list", "arrayOf");
         instantiationTypes.put("map", "mapOf");
 
         importMapping = new HashMap<String, String>();
@@ -241,6 +241,7 @@ public class KotlinClientCodegen extends DefaultCodegen implements CodegenConfig
         final String infrastructureFolder = (sourceFolder + File.separator + packageName + File.separator + "infrastructure").replace(".", "/");
 
         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/ApiInfrastructureResponse.kt.mustache", infrastructureFolder, "ApiInfrastructureResponse.kt"));
         supportingFiles.add(new SupportingFile("infrastructure/ApplicationDelegates.kt.mustache", infrastructureFolder, "ApplicationDelegates.kt"));
         supportingFiles.add(new SupportingFile("infrastructure/RequestConfig.kt.mustache", infrastructureFolder, "RequestConfig.kt"));

modules/swagger-codegen/src/main/resources/kotlin-client/api.mustache

@@ -19,7 +19,7 @@ class {{classname}}(basePath: kotlin.String = "{{{basePath}}}") : ApiClient(base
     @Suppress("UNCHECKED_CAST"){{/returnType}}
     fun {{operationId}}({{#allParams}}{{paramName}}: {{{dataType}}}{{#hasMore}}, {{/hasMore}}{{/allParams}}) : {{#returnType}}{{{returnType}}}{{/returnType}}{{^returnType}}Unit{{/returnType}} {
         val localVariableBody: kotlin.Any? = {{#hasBodyParam}}{{#bodyParams}}{{paramName}}{{/bodyParams}}{{/hasBodyParam}}{{^hasBodyParam}}{{^hasFormParams}}null{{/hasFormParams}}{{#hasFormParams}}mapOf({{#formParams}}"{{{baseName}}}" to "${{paramName}}"{{#hasMore}}, {{/hasMore}}{{/formParams}}){{/hasFormParams}}{{/hasBodyParam}}
-        val localVariableQuery: kotlin.collections.Map<kotlin.String,kotlin.String> = {{^hasQueryParams}}mapOf(){{/hasQueryParams}}{{#hasQueryParams}}mapOf({{#queryParams}}"{{paramName}}" to {{#isContainer}}{{paramName}}.joinToString(separator = collectionDelimiter("{{collectionFormat}}")){{/isContainer}}{{^isContainer}}{{paramName}}{{/isContainer}}{{#hasMore}}, {{/hasMore}}{{/queryParams}}){{/hasQueryParams}}
+        val localVariableQuery: MultiValueMap = {{^hasQueryParams}}mapOf(){{/hasQueryParams}}{{#hasQueryParams}}mapOf({{#queryParams}}"{{paramName}}" to {{#isContainer}}toMultiValue({{paramName}}.toList(), "{{collectionFormat}}"){{/isContainer}}{{^isContainer}}listOf("${{paramName}}"){{/isContainer}}{{#hasMore}}, {{/hasMore}}{{/queryParams}}){{/hasQueryParams}}
         val localVariableHeaders: kotlin.collections.Map<kotlin.String,kotlin.String> = {{^headerParams}}mapOf({{#hasFormParams}}"Content-Type" to "multipart/form-data"{{/hasFormParams}}){{/headerParams}}{{#headerParams}}mapOf("{{paramName}}" to {{#isContainer}}{{paramName}}.joinToString(separator = collectionDelimiter("{{collectionFormat}}")){{/isContainer}}{{^isContainer}}{{paramName}}{{/isContainer}}){{/headerParams}}
         val localVariableConfig = RequestConfig(
             RequestMethod.{{httpMethod}},
@@ -43,13 +43,5 @@ class {{classname}}(basePath: kotlin.String = "{{{basePath}}}") : ApiClient(base
     }
 
     {{/operation}}
-
-    private fun collectionDelimiter(collectionFormat: kotlin.String) = when(collectionFormat) {
-        "csv" -> ","
-        "tsv" -> "\t"
-        "pipes" -> "|"
-        "ssv" -> " "
-        else -> ""
-    }
 }
 {{/operations}}

modules/swagger-codegen/src/main/resources/kotlin-client/infrastructure/ApiAbstractions.kt.mustache

@@ -0,0 +1,20 @@
+package {{packageName}}.infrastructure
+
+typealias MultiValueMap = Map<String,List<String>>
+
+fun collectionDelimiter(collectionFormat: String) = when(collectionFormat) {
+    "csv" -> ","
+    "tsv" -> "\t"
+    "pipes" -> "|"
+    "ssv" -> " "
+    else -> ""
+}
+
+val defaultMultiValueConverter: (item: Any?) -> String = { item -> "$item" }
+
+fun <T: Any?> toMultiValue(items: List<T>, collectionFormat: String, map: (item: Any?) -> String = defaultMultiValueConverter): List<String> {
+    return when(collectionFormat) {
+        "multi" -> items.map(map)
+        else -> listOf(items.map(map).joinToString(separator = collectionDelimiter(collectionFormat)))
+    }
+}

modules/swagger-codegen/src/main/resources/kotlin-client/infrastructure/ApiClient.kt.mustache

@@ -60,7 +60,11 @@ open class ApiClient(val baseUrl: String) {
         var urlBuilder = httpUrl.newBuilder()
                 .addPathSegments(requestConfig.path.trimStart('/'))
 
-        requestConfig.query.forEach { k, v -> urlBuilder = urlBuilder.addQueryParameter(k,v) }
+        requestConfig.query.forEach { k, v ->
+            v.forEach { queryValue ->
+                urlBuilder = urlBuilder.addQueryParameter(k,queryValue)
+            }
+        }
 
         val url = urlBuilder.build()
         val headers = requestConfig.headers + defaultHeaders
@@ -73,6 +77,7 @@ open class ApiClient(val baseUrl: String) {
             throw kotlin.IllegalStateException("Missing Accept header. This is required.")
         }
 
+        // TODO: support multiple contentType,accept options here.
         val contentType = (headers[ContentType] as String).substringBefore(";").toLowerCase()
         val accept = (headers[Accept] as String).substringBefore(";").toLowerCase()
 

modules/swagger-codegen/src/main/resources/kotlin-client/infrastructure/RequestConfig.kt.mustache

@@ -5,9 +5,11 @@ package {{packageName}}.infrastructure
  * NOTE: This object doesn't include 'body' because it
  *       allows for caching of the constructed object
  *       for many request definitions.
+ * NOTE: Headers is a Map<String,String> because rfc2616 defines
+ *       multi-valued headers as csv-only.
  */
 data class RequestConfig(
         val method: RequestMethod,
         val path: String,
         val headers: Map<String, String> = mapOf(),
-        val query: Map<String, String> = mapOf())
+        val query: Map<String, List<String>> = mapOf())

modules/swagger-codegen/src/test/java/io/swagger/codegen/kotlin/KotlinClientCodegenModelTest.java

@@ -104,10 +104,10 @@ public class KotlinClientCodegenModelTest {
         Assert.assertEquals(property.baseName, "examples");
         Assert.assertEquals(property.getter, "getExamples");
         Assert.assertEquals(property.setter, "setExamples");
-        Assert.assertEquals(property.datatype, "kotlin.collections.List<kotlin.String>");
+        Assert.assertEquals(property.datatype, "kotlin.Array<kotlin.String>");
         Assert.assertEquals(property.name, "examples");
         Assert.assertEquals(property.defaultValue, "null");
-        Assert.assertEquals(property.baseType, "kotlin.collections.List");
+        Assert.assertEquals(property.baseType, "kotlin.Array");
         Assert.assertEquals(property.containerType, "array");
         Assert.assertFalse(property.required);
         Assert.assertTrue(property.isContainer);