define and document http client behaviour

README.md

@@ -67,6 +67,7 @@ config :sentry,
 | `release` | False  | None | |
 | `server_name` | False  | None | |
 | `use_error_logger` | False  | False | |
+| `client` | False  | `Sentry.Client` | If you need different functionality for the HTTP client, you can define your own module that implements the `Sentry.HTTPClient` behaviour and set `client` to that module |
 | `hackney_opts` | False  | `[pool: :sentry_pool]` | |
 | `hackney_pool_max_connections` | False  | 50 | |
 | `hackney_pool_timeout` | False  | 5000 | |

docs/config.rst

@@ -60,6 +60,10 @@ Optional settings
   Set this to true if you want to capture all exceptions that occur even outside of a request cycle. This
   defaults to false.
 
+.. describe:: client
+
+  If you need different functionality for the HTTP client, you can define your own module that implements the `Sentry.HTTPClient` behaviour and set `client` to that module.
+
 .. describe:: filter
 
   Set this to a module that implements the ``Sentry.EventFilter`` behaviour if you would like to prevent

lib/sentry/client.ex

@@ -1,4 +1,6 @@
 defmodule Sentry.Client do
+  @behaviour Sentry.HTTPClient
+
   @moduledoc """
   This module is the default client for sending an event to Sentry via HTTP.
 

lib/sentry/http_client.ex

@@ -0,0 +1,12 @@
+defmodule Sentry.HTTPClient do
+  @moduledoc """
+  Specifies the API for using a custom HTTP Client.
+
+  Clients must implement the `send_event/1` function that receives
+  the Event and sends it to the Sentry API.  It may return anything.
+
+  See `Sentry.Client` for `Sentry.TestClient` for example implementations.
+  """
+
+  @callback send_event(Sentry.Event.t) :: any
+end

test/support/test_client.ex

@@ -1,4 +1,6 @@
 defmodule Sentry.TestClient do
+  @behaviour Sentry.HTTPClient
+
   def send_event(%Sentry.Event{} = event) do
     {endpoint, _public_key, _secret_key} = Sentry.Client.get_dsn!
     event = Sentry.Client.maybe_call_before_send_event(event)