Add error messages for repeated follows and unfollows

lib/pleroma/user.ex

@@ -31,6 +31,10 @@ defmodule Pleroma.User do
 
   def follow(%User{} = follower, %User{} = followed) do
     ap_followers = User.ap_followers(followed)
+    if following?(follower, followed) do
+      { :error,
+        "Could not follow user: #{followed.nickname} is already on your list." }
+    else
       following = [ap_followers | follower.following]
       |> Enum.uniq
 
@@ -38,15 +42,20 @@ defmodule Pleroma.User do
       |> follow_changeset(%{following: following})
       |> Repo.update
     end
+  end
 
   def unfollow(%User{} = follower, %User{} = followed) do
     ap_followers = User.ap_followers(followed)
+    if following?(follower, followed) do
       following = follower.following
       |> List.delete(ap_followers)
 
       follower
       |> follow_changeset(%{following: following})
       |> Repo.update
+    else
+      { :error, "Not subscribed!" }
+    end
   end
 
   def following?(%User{} = follower, %User{} = followed) do

lib/pleroma/web/twitter_api/twitter_api.ex

@@ -112,6 +112,8 @@ defmodule Pleroma.Web.TwitterAPI.TwitterAPI do
          })
     do
       { :ok, follower, followed, activity }
+    else
+      err -> err
     end
   end
 
@@ -120,6 +122,8 @@ defmodule Pleroma.Web.TwitterAPI.TwitterAPI do
          { :ok, follower } <- User.unfollow(follower, followed)
     do
       { :ok, follower, followed }
+    else
+      err -> err
     end
   end
 

lib/pleroma/web/twitter_api/twitter_api_controller.ex

@@ -44,21 +44,24 @@ defmodule Pleroma.Web.TwitterAPI.Controller do
   end
 
   def follow(%{assigns: %{user: user}} = conn, %{ "user_id" => followed_id }) do
-    { :ok, _user, follower, _activity } = TwitterAPI.follow(user, followed_id)
+    case TwitterAPI.follow(user, followed_id) do
+      { :ok, _user, followed, _activity } ->
+        response = followed |> UserRepresenter.to_json(%{for: user})
+        conn |> json_reply(200, response)
+      { :error, msg } -> forbidden_json_reply(conn, msg)
+    end
 
-    response = follower |> UserRepresenter.to_json(%{for: user})
-
-    conn
-    |> json_reply(200, response)
   end
 
   def unfollow(%{assigns: %{user: user}} = conn, %{ "user_id" => followed_id }) do
-    { :ok, user, follower } = TwitterAPI.unfollow(user, followed_id)
-
-    response = follower |> UserRepresenter.to_json(%{for: user})
+    case TwitterAPI.unfollow(user, followed_id) do
+      { :ok, user, followed } ->
+        response = followed |> UserRepresenter.to_json(%{for: user})
 
         conn
         |> json_reply(200, response)
+      { :error, msg } -> forbidden_json_reply(conn, msg)
+    end
   end
 
   def fetch_status(%{assigns: %{user: user}} = conn, %{ "id" => id }) do
@@ -88,4 +91,11 @@ defmodule Pleroma.Web.TwitterAPI.Controller do
     |> put_resp_content_type("application/json")
     |> send_resp(status, json)
   end
+
+  defp forbidden_json_reply(conn, error_message) do
+    json = %{"error" => error_message, "request" => conn.request_path}
+    |> Poison.encode!
+
+    json_reply(conn, 403, json)
+  end
 end

test/web/twitter_api/twitter_api_test.exs

@@ -105,26 +105,31 @@ defmodule Pleroma.Web.TwitterAPI.TwitterAPITest do
 
   test "Follow another user" do
     { :ok, user } = UserBuilder.insert
-    { :ok, following } = UserBuilder.insert(%{nickname: "guy"})
+    { :ok, followed } = UserBuilder.insert(%{nickname: "guy"})
 
-    {:ok, user, following, activity } = TwitterAPI.follow(user, following.id)
+    { :ok, user, followed, activity } = TwitterAPI.follow(user, followed.id)
 
     user = Repo.get(User, user.id)
     follow = Repo.get(Activity, activity.id)
 
-    assert user.following == [User.ap_followers(following)]
+    assert user.following == [User.ap_followers(followed)]
     assert follow == activity
+
+    { :error, msg } = TwitterAPI.follow(user, followed.id)
+    assert msg == "Could not follow user: #{followed.nickname} is already on your list."
   end
 
   test "Unfollow another user" do
-    { :ok, following } = UserBuilder.insert(%{nickname: "guy"})
-    { :ok, user } = UserBuilder.insert(%{following: [User.ap_followers(following)]})
+    { :ok, followed } = UserBuilder.insert(%{nickname: "guy"})
+    { :ok, user } = UserBuilder.insert(%{following: [User.ap_followers(followed)]})
 
-    {:ok, user, _following } = TwitterAPI.unfollow(user, following.id)
+    { :ok, user, _followed } = TwitterAPI.unfollow(user, followed.id)
 
     user = Repo.get(User, user.id)
 
     assert user.following == []
+    { :error, msg } = TwitterAPI.unfollow(user, followed.id)
+    assert msg == "Not subscribed!"
   end
 
   test "fetch statuses in a context using the conversation id" do