Add ability to specify description in Rollbax.Exception

lib/rollbax.ex

@@ -235,12 +235,13 @@ defmodule Rollbax do
     %{
       class: class,
       message: message,
+      description: description,
       stacktrace: stacktrace,
       custom: custom,
       occurrence_data: occurrence_data
     } = exception
 
-    body = Rollbax.Item.exception_body(class, message, stacktrace)
+    body = Rollbax.Item.exception_body(class, message, description, stacktrace)
     Rollbax.Client.emit(:error, System.system_time(:second), body, custom, occurrence_data)
   end
 end

lib/rollbax/exception.ex

@@ -2,6 +2,7 @@ defmodule Rollbax.Exception do
   @type t :: %__MODULE__{
           class: String.t(),
           message: String.t(),
+          description: String.t(),
           stacktrace: Exception.stacktrace(),
           custom: map,
           occurrence_data: map
@@ -10,6 +11,7 @@ defmodule Rollbax.Exception do
   defstruct [
     :class,
     :message,
+    :description,
     :stacktrace,
     custom: %{},
     occurrence_data: %{}

lib/rollbax/item.ex

@@ -46,16 +46,17 @@ defmodule Rollbax.Item do
   `class` and `message` are strings that will be used as the class and message
   of the reported exception. `stacktrace` is the stacktrace of the error.
   """
-  @spec exception_body(String.t(), String.t(), [any]) :: map
-  def exception_body(class, message, stacktrace)
+  @spec exception_body(String.t(), String.t(), String.t() | nil, [any]) :: map
+  def exception_body(class, message, description \\ nil, stacktrace)
       when is_binary(class) and is_binary(message) and is_list(stacktrace) do
     %{
       "trace" => %{
         "frames" => stacktrace_to_frames(stacktrace),
         "exception" => %{
           "class" => class,
-          "message" => message
+          "message" => message,
         }
+        |> put_if_present("description", description)
       }
     }
   end
@@ -166,4 +167,7 @@ defmodule Rollbax.Item do
       "version" => unquote(Mix.Project.config()[:version])
     }
   end
+
+  defp put_if_present(map, _field, nil), do: map
+  defp put_if_present(map, field, value), do: Map.put(map, field, value)
 end