fix: content type header not present in multipart item

requests/src/requests/Model.scala

@@ -132,6 +132,9 @@ object RequestBlob{
       partBytes.foreach {
         case(name, filename, part) =>
           writeBytes(pref + boundary + crlf)
+          part.data.headers.foreach { case (headerName, headerValue) =>
+            writeBytes(s"$headerName: $headerValue$crlf")
+          }
           writeBytes(ContentDisposition)
           out.write(name)
           if (filename.nonEmpty){

requests/test/src/requests/ModelTests.scala

@@ -0,0 +1,47 @@
+package requests
+
+import java.io.ByteArrayOutputStream
+import java.io.File
+import java.nio.file.{FileSystems, Path}
+
+import utest._
+
+object ModelTests extends TestSuite{
+  val tests = Tests {
+    test("multipart file uploads should contain application/octet-stream content type") {
+      val path = getClass.getResource("/license.zip").getPath
+      val file = new File(path)
+      val nioPath = FileSystems.getDefault.getPath(path)
+      val fileKey = "fileKey"
+      val fileName = "fileName"
+
+      val javaFileMultipart = MultiPart(
+        MultiItem(
+          fileKey,
+          file,
+          fileName
+        )
+      )
+
+      val nioPathMultipart = MultiPart(
+        MultiItem(
+          fileKey,
+          nioPath,
+          fileName
+        )
+      )
+
+      val javaFileOutputStream = new ByteArrayOutputStream()
+      val nioPathOutputStream = new ByteArrayOutputStream()
+
+      javaFileMultipart.write(javaFileOutputStream)
+      nioPathMultipart.write(nioPathOutputStream)
+
+      val javaFileString = new String(javaFileOutputStream.toByteArray)
+      val nioPathString = new String(nioPathOutputStream.toByteArray)
+
+      assert(javaFileString.contains("Content-Type: application/octet-stream"))
+      assert(nioPathString.contains("Content-Type: application/octet-stream"))
+    }
+  }
+}