Behaviour for Volt build plugins.

Plugins hook into the compilation pipeline at four stages:

1. resolve — remap import specifiers before file lookup
2. load — provide virtual module content for a specifier
3. transform — modify compiled output before it's served/bundled
4. render_chunk — modify final bundled chunks before writing

Each callback is optional. Return nil or :pass to skip.

Example

defmodule MyApp.SvgPlugin do
  @behaviour Volt.Plugin

  @impl true
  def name, do: "svg"

  @impl true
  def resolve(specifier, _importer) do
    if String.ends_with?(specifier, ".svg") do
      {:ok, specifier}
    end
  end

  @impl true
  def load(path) do
    if String.ends_with?(path, ".svg") do
      svg = File.read!(path)
      {:ok, "export default " <> Jason.encode!(svg), "application/javascript"}
    end
  end

  @impl true
  def transform(_code, _path), do: nil

  @impl true
  def render_chunk(_code, _chunk_info), do: nil
end