# ChannelWatcher
[![build status](https://gitlab.com/cap-public/packages/channel-watcher/badges/master/pipeline.svg)](https://gitlab.com/cap-public/packages/channel-watcher/-/commits/master)
[![coverage report](https://gitlab.com/cap-public/packages/channel-watcher/badges/master/coverage.svg)](https://cap-public.gitlab.io/packages/channel-watcher/coverage/excoveralls.html)
A [GenServer](https://hexdocs.pm/elixir/GenServer.html) to monitor PIDs and run callbacks when they go down.
This is essentially a _slightly_ improved version of Chris McCord's answer to a [StackOverflow question](https://stackoverflow.com/a/33941469).
## Installation
The package can be installed by adding `channel_watcher` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[
{:channel_watcher, "~> 0.1.0"}
]
end
```
## Usage
Drop this in a module for a process you wish to test (such as a [Phoenix channel](https://hexdocs.pm/phoenix/channels.html)):
```elixir
:ok = ChannelWatcher.monitor(self(), {__MODULE__, CALLBACK, [ARGS]})
```
Make sure to replace `CALLBACK` with an atom of your callback function name, and `[ARGS]` with a list of arguments to pass to that callback.
The [test](https://gitlab.com/cap-public/packages/channel-watcher/-/blob/master/test/channel_watcher_test.exs) also shows an example of usage.