Mastodon API: Set follower/following counters to 0 when hiding

followers/following is enabled

We are already doing that in AP representation, so I think we should do
it here as well for consistency.

test/web/mastodon_api/account_view_test.exs

@@ -356,4 +356,31 @@ defmodule Pleroma.Web.MastodonAPI.AccountViewTest do
     result = AccountView.render("account.json", %{user: user})
     refute result.display_name == "<marquee> username </marquee>"
   end
+
+  describe "hiding follows/following" do
+    test "shows when follows/following are hidden and sets follower/following count to 0" do
+      user = insert(:user, info: %{hide_followers: true, hide_follows: true})
+      other_user = insert(:user)
+      {:ok, user, other_user, _activity} = CommonAPI.follow(user, other_user)
+      {:ok, _other_user, user, _activity} = CommonAPI.follow(other_user, user)
+
+      assert %{
+               followers_count: 0,
+               following_count: 0,
+               pleroma: %{hide_follows: true, hide_followers: true}
+             } = AccountView.render("account.json", %{user: user})
+    end
+
+    test "shows actual follower/following count to the account owner" do
+      user = insert(:user, info: %{hide_followers: true, hide_follows: true})
+      other_user = insert(:user)
+      {:ok, user, other_user, _activity} = CommonAPI.follow(user, other_user)
+      {:ok, _other_user, user, _activity} = CommonAPI.follow(other_user, user)
+
+      assert %{
+               followers_count: 1,
+               following_count: 1
+             } = AccountView.render("account.json", %{user: user, for: user})
+    end
+  end
 end