Fix dialyzer errors

bin/test

@@ -13,6 +13,8 @@ MIX_ENV=test mix format --check-formatted || { echo 'Please format code with `mi
 
 MIX_ENV=test mix compile --warnings-as-errors --force || { echo 'Please fix all compiler warnings.'; exit 1; }
 
+MIX_ENV=test mix dialyze || { echo 'Please fix all dialyzer errors.'; exit 1; }
+
 MIX_ENV=test mix docs  || { echo 'Elixir HTML docs were not generated!'; exit 1; }
 
 mix test || { echo 'Elixir tests failed!'; exit 1; }

lib/ex_twilio/api.ex

@@ -15,7 +15,6 @@ defmodule ExTwilio.Api do
   Items are returned as instances of the given module's struct. For more
   details, see the documentation for each function.
   """
-
   use HTTPoison.Base
 
   alias ExTwilio.Config
@@ -170,14 +169,25 @@ defmodule ExTwilio.Api do
 
   def auth_header(headers, _), do: headers
 
+  @spec format_data(any) :: binary
+  def format_data(data)
+
+  def format_data(data) when is_map(data) do
+    data
+    |> Map.to_list()
+    |> Url.to_query_string()
+  end
+
+  def format_data(data) when is_list(data) do
+    Url.to_query_string(data)
+  end
+
+  def format_data(data), do: data
+
   ###
   # HTTPotion API
   ###
 
-  @doc """
-  Automatically adds the correct headers to each API request.
-  """
-  @spec process_request_headers(list) :: list
   def process_request_headers(headers \\ []) do
     headers
     |> Keyword.put(:"Content-Type", "application/x-www-form-urlencoded; charset=UTF-8")
@@ -187,17 +197,4 @@ defmodule ExTwilio.Api do
   def process_request_options(options) do
     Keyword.merge(options, Config.request_options())
   end
-
-  @spec format_data(data) :: binary
-  def format_data(data) when is_map(data) do
-    data
-    |> Map.to_list()
-    |> Url.to_query_string()
-  end
-
-  def format_data(data) when is_list(data) do
-    Url.to_query_string(data)
-  end
-
-  def format_data(data), do: data
 end

lib/ex_twilio/jwt/access_token.ex

@@ -95,7 +95,7 @@ defmodule ExTwilio.JWT.AccessToken do
         "cty" => "twilio-fpa;v=1"
       })
 
-    Joken.generate_and_sign!(token_config, nil, signer)
+    Joken.generate_and_sign!(token_config, %{}, signer)
   end
 
   defp list_of_grants?(grants) when is_list(grants) do

lib/ex_twilio/url_generator.ex

@@ -147,6 +147,8 @@ defmodule ExTwilio.UrlGenerator do
   end
 
   @spec add_account_to_options(atom, list) :: list
+  defp add_account_to_options(module, options)
+
   defp add_account_to_options(module, options) do
     if module == ExTwilio.Account and options[:account] == nil do
       options
@@ -155,7 +157,6 @@ defmodule ExTwilio.UrlGenerator do
     end
   end
 
-  @spec add_account_to_options(atom, list) :: list
   defp add_flow_to_options(_module, options) do
     Keyword.put_new(options, :flow, Keyword.get(options, :flow_sid))
   end