Remove Application.get_env call from Nostrum.Api.Base

Closes #546

lib/nostrum/api/base.ex

@@ -6,12 +6,23 @@ defmodule Nostrum.Api.Base do
   import Nostrum.Constants, only: [base_route: 0]
   require Logger
 
+  @typedoc "An anonymous function that returns the bot token."
+  @type wrapped_token :: (() -> String.t())
+
   @type methods :: :get | :post | :put | :delete
 
-  @spec request(pid, methods(), String.t(), iodata(), [{String.t(), String.t()}], Enum.t()) ::
+  @spec request(
+          pid,
+          methods(),
+          String.t(),
+          iodata(),
+          [{String.t(), String.t()}],
+          Enum.t(),
+          wrapped_token()
+        ) ::
           :gun.stream_ref()
-  def request(conn, method, route, body, raw_headers, params) do
-    headers = process_request_headers(raw_headers)
+  def request(conn, method, route, body, raw_headers, params, wrapped_token) do
+    headers = process_request_headers(raw_headers, wrapped_token)
     # Convert method from atom to string for `:gun`
     method =
       method
@@ -21,24 +32,21 @@ defmodule Nostrum.Api.Base do
     query_string = URI.encode_query(params)
 
     full_route = "#{base_route()}#{route}?#{query_string}"
-    headers = process_request_headers(headers, body)
+    headers = finalize_request_headers(headers, body)
     :gun.request(conn, method, full_route, headers, process_request_body(body))
   end
 
-  def process_request_headers(headers, ""), do: :proplists.delete("content-type", headers)
-  def process_request_headers(headers, _body), do: headers
+  def finalize_request_headers(headers, ""), do: :proplists.delete("content-type", headers)
+  def finalize_request_headers(headers, _body), do: headers
   def process_request_body(""), do: ""
   def process_request_body({:multipart, content}), do: content
   def process_request_body(body), do: Jason.encode_to_iodata!(body)
 
-  def process_request_headers(headers) do
-    user_agent = [
+  def process_request_headers(headers, wrapped_token) do
+    [
+      {"authorization", "Bot #{wrapped_token.()}"},
       {"user-agent", "DiscordBot (https://github.com/kraigie/nostrum, #{@version})"} | headers
     ]
-
-    token = "Bot #{Application.get_env(:nostrum, :token)}"
-
-    [{"authorization", token} | user_agent]
   end
 
   def process_response_body(body) do

lib/nostrum/api/ratelimiter.ex

@@ -279,6 +279,10 @@ defmodule Nostrum.Api.Ratelimiter do
 
   - `:remaining_in_window`: How many calls we may still make to the API during
   this time window. Reset automatically via timeouts.
+
+  - `:wrapped_token`: An anonymous function that is internally used to retrieve
+  the token. This is wrapped to ensure that it is not accidentally exposed in
+  stacktraces.
   """
   @typedoc since: "0.9.0"
   @type state :: %{
@@ -294,23 +298,24 @@ defmodule Nostrum.Api.Ratelimiter do
                body :: String.t()}
           },
           conn: pid() | nil,
-          remaining_in_window: non_neg_integer()
+          remaining_in_window: non_neg_integer(),
+          wrapped_token: Base.wrapped_token()
         }
 
   @doc """
   Starts the ratelimiter.
   """
-  @spec start_link([:gen_statem.start_opt()]) :: :gen_statem.start_ret()
-  def start_link(opts) do
-    :gen_statem.start_link({:local, @registered_name}, __MODULE__, [], opts)
+  @spec start_link({String.t(), [:gen_statem.start_opt()]}) :: :gen_statem.start_ret()
+  def start_link({token, opts}) do
+    :gen_statem.start_link({:local, @registered_name}, __MODULE__, token, opts)
   end
 
-  def init([]) do
+  def init(token) when is_binary(token) do
     # Uncomment the following to trace everything the ratelimiter is doing:
     #   me = self()
     #   spawn(fn -> :sys.trace(me, true) end)
     # See more examples in the `sys` docs.
-    {:ok, :disconnected, empty_state()}
+    {:ok, :disconnected, empty_state(token)}
   end
 
   def callback_mode, do: :state_functions
@@ -469,7 +474,12 @@ defmodule Nostrum.Api.Ratelimiter do
   def connected(
         :internal,
         {:run, request, bucket, from},
-        %{conn: conn, outstanding: outstanding, remaining_in_window: remaining_for_user} = data
+        %{
+          conn: conn,
+          outstanding: outstanding,
+          remaining_in_window: remaining_for_user,
+          wrapped_token: wrapped_token
+        } = data
       )
       when remaining_for_user > 0 and is_map_key(outstanding, bucket) do
     stream =
@@ -479,7 +489,8 @@ defmodule Nostrum.Api.Ratelimiter do
         request.route,
         request.body,
         request.headers,
-        request.params
+        request.params,
+        wrapped_token
       )
 
     data_with_this_running = put_in(data, [:running, stream], {bucket, request, from})
@@ -865,7 +876,10 @@ defmodule Nostrum.Api.Ratelimiter do
      {:next_event, :internal, {:requeue, {request, from}}}}
   end
 
-  def connected(:info, {:gun_down, conn, _, reason, killed_streams}, %{running: running}) do
+  def connected(:info, {:gun_down, conn, _, reason, killed_streams}, %{
+        running: running,
+        wrapped_token: wrapped_token
+      }) do
     # Even with `retry: 0`, gun seems to try and reconnect, potentially because
     # of WebSocket. Force the connection to die.
     :ok = :gun.close(conn)
@@ -886,7 +900,7 @@ defmodule Nostrum.Api.Ratelimiter do
         {:reply, client, {:error, {:connection_died, reason}}}
       end)
 
-    {:next_state, :disconnected, empty_state(), replies}
+    {:next_state, :disconnected, empty_state(wrapped_token.()), replies}
   end
 
   def global_limit(:state_timeout, next, data) do
@@ -936,14 +950,15 @@ defmodule Nostrum.Api.Ratelimiter do
   defp parse_response(status, headers, buffer),
     do: {:ok, {status, headers, buffer}}
 
-  @spec empty_state :: state()
-  defp empty_state,
+  @spec empty_state(String.t()) :: state()
+  defp empty_state(token),
     do: %{
       outstanding: %{},
       running: %{},
       inflight: %{},
       conn: nil,
-      remaining_in_window: @bot_calls_per_window
+      remaining_in_window: @bot_calls_per_window,
+      wrapped_token: fn -> token end
     }
 
   # Helper functions

lib/nostrum/application.ex

@@ -28,7 +28,7 @@ defmodule Nostrum.Application do
     children = [
       Nostrum.Store.Supervisor,
       Nostrum.ConsumerGroup,
-      Nostrum.Api.Ratelimiter,
+      {Nostrum.Api.Ratelimiter, {Application.fetch_env!(:nostrum, :token), []}},
       Nostrum.Shard.Connector,
       Nostrum.Cache.CacheSupervisor,
       Nostrum.Shard.Supervisor,