Ensure Facebook returns application/json content type

CHANGELOG.md

@@ -8,6 +8,7 @@
 * `Assent.Strategy.OIDC` now supports `none` authentication method
 * `Assent.Strategy.Bitbucket` added
 * `Assent.Strategy.Twitch` added
+* `Assent.Strategy.Facebook.fetch_user/2` fixed bug with user not being decoded
 * `Assent.Strategy.OAuth2` now supports PKCE
 * `Assent.Strategy.OAuth2.Base.authorize_url/2` incomplete typespec fixed
 * `Assent.Strategy.decode_response/2` deprecated accepting result tuples and now accepts `Assent.HTTPAdapter.HTTPResponse` structs

lib/assent/strategies/facebook.ex

@@ -115,7 +115,7 @@ defmodule Assent.Strategy.Facebook do
         access_token: access_token["access_token"]
       ]
 
-      OAuth2.fetch_user(config, access_token, params)
+      OAuth2.fetch_user(config, access_token, params, [{"accept", "application/json"}])
     end
   end
 

test/assent/strategies/facebook_test.exs

@@ -31,6 +31,8 @@ defmodule Assent.Strategy.FacebookTest do
       end)
 
       expect_oauth2_user_request(@user_response, [uri: "/me"], fn conn ->
+        assert Plug.Conn.get_req_header(conn, "accept") == ["application/json"]
+
         conn = Plug.Conn.fetch_query_params(conn)
 
         assert conn.params["access_token"] == "access_token"