Multiple files upload

fuel/src/main/kotlin/com/github/kittinunf/fuel/core/Request.kt

@@ -131,7 +131,7 @@ class Request : Fuel.RequestConvertible {
         return this
     }
 
-    fun source(source: (Request, URL) -> File): Request {
+    fun sources(source: (Request, URL) -> Iterable<File>): Request {
         val uploadTaskRequest = taskRequest as? UploadTaskRequest ?: throw IllegalStateException("source is only used with RequestType.UPLOAD")
 
         uploadTaskRequest.apply {
@@ -140,6 +140,14 @@ class Request : Fuel.RequestConvertible {
         return this
     }
 
+    fun source(source: (Request, URL) -> File): Request {
+        sources { request, url ->
+            listOf(source.invoke(request, request.url))
+        }
+
+        return this
+    }
+
     fun name(name: () -> String): Request {
         this.name = name()
         return this

fuel/src/main/kotlin/com/github/kittinunf/fuel/core/requests/UploadTaskRequest.kt

@@ -19,35 +19,43 @@ class UploadTaskRequest(request: Request) : TaskRequest(request) {
     val boundary = request.httpHeaders["Content-Type"]?.split("=", limit = 2)?.get(1) ?: System.currentTimeMillis().toHexString()
 
     var progressCallback: ((Long, Long) -> Unit)? = null
-    lateinit var sourceCallback: ((Request, URL) -> File)
+    lateinit var sourceCallback: (Request, URL) -> Iterable<File>
 
     var dataStream: ByteArrayOutputStream? = null
-    var fileInputStream: FileInputStream? = null
 
     override fun call(): Response {
         try {
-            val file = sourceCallback.invoke(request, request.url)
-            //file input
-            fileInputStream = FileInputStream(file)
             dataStream = ByteArrayOutputStream().apply {
-                write("--" + boundary + CRLF)
-                write("Content-Disposition: form-data; name=\"" + request.name + "\"; filename=\"" + file.name + "\"")
-                write(CRLF)
-                write("Content-Type: " + URLConnection.guessContentTypeFromName(file.name))
-                write(CRLF)
-                write(CRLF)
+                val files = sourceCallback.invoke(request, request.url)
 
-                //input file data
-                fileInputStream!!.copyTo(this, BUFFER_SIZE) { writtenBytes ->
-                    progressCallback?.invoke(writtenBytes, file.length())
-                }
+                files.forEachIndexed { i, file ->
+                    val postFix = if (files.count() == 1) "" else "${i + 1}"
 
-                write(CRLF)
+                    write("--$boundary")
+                    write(CRLF)
+                    write("Content-Disposition: form-data; name=\"" + request.name + "$postFix\"; filename=\"${file.name}\"")
+                    write(CRLF)
+                    write("Content-Type: " + URLConnection.guessContentTypeFromName(file.name))
+                    write(CRLF)
+                    write(CRLF)
+
+                    //input file data
+                    FileInputStream(file).use {
+                        it.copyTo(this, BUFFER_SIZE) { writtenBytes ->
+                            progressCallback?.invoke(writtenBytes, file.length())
+                        }
+                    }
+
+                    write(CRLF)
+                }
 
                 request.parameters.forEach {
-                    write("--$boundary" + CRLF)
-                    write("Content-Disposition: form-data; name=\"" + it.first + "\"" + CRLF)
-                    write("Content-Type: text/plain" + CRLF)
+                    write("--$boundary")
+                    write(CRLF)
+                    write("Content-Disposition: form-data; name=\"${it.first}\"")
+                    write(CRLF)
+                    write("Content-Type: text/plain")
+                    write(CRLF)
                     write(CRLF)
                     write(it.second.toString())
                     write(CRLF)
@@ -62,7 +70,6 @@ class UploadTaskRequest(request: Request) : TaskRequest(request) {
             return super.call()
         } finally {
             dataStream?.close()
-            fileInputStream?.close()
         }
     }
 }

fuel/src/test/kotlin/com/github/kittinunf/fuel/RequestUploadTest.kt

@@ -201,4 +201,38 @@ class RequestUploadTest : BaseTestCase() {
         assertThat(response?.httpStatusCode, isEqualTo(statusCode))
     }
 
+    @Test
+    fun httpUploadWithMultipleFiles() {
+        var request: Request? = null
+        var response: Response? = null
+        var data: Any? = null
+        var error: FuelError? = null
+
+        manager.upload("/post", param = listOf("foo" to "bar"))
+                .sources { request, url ->
+                    listOf(File(currentDir, "lorem_ipsum_short.tmp"),
+                            File(currentDir, "lorem_ipsum_long.tmp"))
+                }
+                .name { "file-name" }
+                .responseString { req, res, result ->
+                    request = req
+                    response = res
+                    val (d, err) = result
+                    data = d
+                    error = err
+                    print(d)
+                }
+
+        assertThat(request, notNullValue())
+        assertThat(response, notNullValue())
+        assertThat(error, nullValue())
+        assertThat(data, notNullValue())
+
+        val string = data as String
+        assertThat(string, containsString("file-name1"))
+        assertThat(string, containsString("file-name2"))
+
+        val statusCode = HttpURLConnection.HTTP_OK
+        assertThat(response?.httpStatusCode, isEqualTo(statusCode))
+    }
 }