finatra-http: add an additional http post helper for tests

Summary: Problem

It is not possible to create a non-multipart post request with repeating params e.g.

    curl -X POST http://example.com/post_endpoint -d foo=bar -d foo=baz

since the httpFormPost param arg is of type Map[String, String]

Solution

Add an additional multipart boolean param to method httpMultipartFormPost
that is passed on to formPost

Differential Revision: https://phabricator.twitter.biz/D113151

CHANGELOG.md

@@ -11,6 +11,9 @@ All notable changes to this project will be documented in this file. Note that `
 
 ### Changed
 
+* finatra-http: add a `multipart = true` arg to
+  `EmbeddedHttpServer.httpMultipartFormPost`
+  ``PHAB_ID=D113151`
 * inject-sever: Do not use the `c.t.inject.server.EmbeddedTwitterServer` 
   `InMemoryStatsReceiver` for embedded http clients. The http client stats are
   emitted with the server under test stats which can be confusing, thus we now 

http/src/test/scala/com/twitter/finatra/http/EmbeddedHttpServer.scala

@@ -925,6 +925,7 @@ class EmbeddedHttpServer(
    *
    * @param path - URI of the request
    * @param params - a Seq of [[com.twitter.finagle.http.FormElement]] to send in the request
+   * @param multipart - if this form post is a multi-part request, true by default
    * @param routeToAdminServer - force the request to the admin interface of the embedded server, false by default.
    * @param headers - additional headers that should be passed with the request
    * @param andExpect - expected [[com.twitter.finagle.http.Status]] value
@@ -937,6 +938,7 @@ class EmbeddedHttpServer(
   def httpMultipartFormPost(
     path: String,
     params: Seq[FormElement],
+    multipart: Boolean = true,
     routeToAdminServer: Boolean = false,
     headers: Map[String, String] = Map.empty,
     andExpect: Status = Status.Ok,
@@ -948,7 +950,7 @@ class EmbeddedHttpServer(
     formPost(
       path = path,
       params = params,
-      multipart = true,
+      multipart = multipart,
       routeToAdminServer = routeToAdminServer,
       headers = headers,
       andExpect = andExpect,