elixir - (RuntimeError) expected action/2 to return a Plug.Conn, all plugs must receive a connection (conn) and return a connection -

in 1 of controllers i've got following code (excerpt):

case httpoison.get("https://*****.zendesk.com/api/v2/users/search.json?query=" <> clid, headers, [hackney: hackney])   {:ok, %httpoison.response{status_code: 200, body: body}} ->     conn     |> put_status(200)     |> json(body)   {:ok, %httpoison.response{status_code: 404}} ->     conn     |> put_status(404)     |> json(%{error_code: "404", reason_given: "resource not found."})   {:error, %httpoison.error{reason: reason}} ->     conn     |> put_status(500)     |> json(%{error_code: "500", reason_given: "none."}) end 

when run code, works fine, phoenix throws runtime exception:

** (exit) exception raised:     ** (runtimeerror) expected action/2 return plug.conn, plugs must receive connection (conn) , return connection         (zentonies) web/controllers/page_controller.ex:1: zentonies.pagecontroller.phoenix_controller_pipeline/2         (zentonies) lib/zentonies/endpoint.ex:1: zentonies.endpoint.instrument/4         (zentonies) lib/phoenix/router.ex:261: zentonies.router.dispatch/2         (zentonies) web/router.ex:1: zentonies.router.do_call/2         (zentonies) lib/zentonies/endpoint.ex:1: zentonies.endpoint.phoenix_pipeline/1         (zentonies) lib/plug/debugger.ex:93: zentonies.endpoint."call (overridable 3)"/2         (zentonies) lib/zentonies/endpoint.ex:1: zentonies.endpoint.call/2         (plug) lib/plug/adapters/cowboy/handler.ex:15: plug.adapters.cowboy.handler.upgrade/4         (cowboy) src/cowboy_protocol.erl:442: :cowboy_protocol.execute/4 

what doing wrong?

the stack trace telling controller action not returning plug.conn struct. in elixir, result of last expression of function returned. @ last line of function , ensure returning result of case expression.

def(conn, params)   final_conn =      case httpoison.get("https://*****.zendesk.com/api/v2/users/search.json?query=" <> clid, headers, [hackney: hackney])       {:ok, %httpoison.response{status_code: 200, body: body}} ->         conn         |> put_status(200)         |> json(body)       {:ok, %httpoison.response{status_code: 404}} ->         conn         |> put_status(404)         |> json(%{error_code: "404", reason_given: "resource not found."})       {:error, %httpoison.error{reason: reason}} ->         conn         |> put_status(500)         |> json(%{error_code: "500", reason_given: "none."})     end    do_something_else(params)    final_conn end