README.md

# ExRerun

### Status

[![Build Status](https://travis-ci.org/dragonwasrobot/ex_rerun.svg?branch=master)](https://travis-ci.org/dragonwasrobot/ex_rerun)

Recompiles mix project on any change to the project src files.

The initial version of this project is inspired by the - currently
unmaintained - `remix` project by AgilionApps:
https://github.com/AgilionApps/remix

## Installation

Install `ex_rerun` by adding it as a dependency to `mix.exs`.

```elixir
def deps do
  [{:ex_rerun, "~> 0.3", only: :dev}]
end
```

If developing a cmd line tool or similar project that does not involve a running
process/server, using `mix run --no-halt` or `iex -S mix` still works for
keeping the `ex_rerun` process alive to monitor and recompile / retest your
code.

## Configuration

It is possible to configure `ex_rerun` using the following parameters:

> Note: the example below shows the default values.

```elixir
config :ex_rerun,
  scan_interval: 4000,
  silent: false,
  file_types: [".ex", ".exs", ".eex", ".json"],
  paths: ["lib", "priv"],
  ignore_pattern: nil,
  tasks: [:elixir]
```

where:

- `scan_interval` specifies the number of ms to wait between rerun checks,
- `silent` toggles whether to print the output of the `tasks` registered, every
  time `ex_rerun` runs,
- `file_types` lists which file types that will trigger a rerun when changed,
- `paths` lists which folders to monitor,
- `ignore_pattern` specifies a regular expression, e.g. `~r{\.?#(.)}`, matching
  files that should to be ignored even if they have a file type included in
  `file_types`, and
- `tasks` enumerates the mix tasks to run each time a code modification
  occurs, possible built-in values are: `:elixir`, `:test`, `:escript`,
  where
  + `:elixir` recompiles Elixir source code (same as `Mix.Tasks.Compile.Elixir`),
  + `:test` reruns any mix tests in the project (same as `Mix.Tasks.Test`), and
  + `escript` rebuilds a escript file (same as `Mix.Tasks.Escript.Build`).

Furthermore, `tasks` can also include custom mix tasks. For example, the hex
package [elm_compile](https://hex.pm/packages/elm_compile) defines the
`Mix.Tasks.Compile.Elm` task which allows mix to also compile Elm files in a mix
project. An example project config using `ex_rerun` and `elm_compile` might look
like so:

```elixir
config :ex_rerun,
  file_types: [".elm", ".ex", ".exs", ".eex", ".json"],
  paths: ["lib", "priv", "web"],
  tasks: [:elixir, Mix.Tasks.Compile.Elm]
```

Another example of a custom mix task could be to generate API documentation for
a project based on a set of `RAML` files.