Clarify the usage of custom type #290

	name: CI

	on:
	pull_request:
	push:
	branches:
	- main

	jobs:
	test:
	runs-on: ubuntu-20.04
	env:
	MIX_ENV: test
	GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
	strategy:
	fail-fast: false
	matrix:
	include:
	# Latest versions
	- pair:
	elixir: "1.17"
	otp: "27.0"
	lint: lint
	coverage: true

	# Oldest supported versions
	- pair:
	elixir: "1.9.4"
	otp: "20.3.8"
	steps:
	- name: Check out this repository
	uses: actions/checkout@v3

	- name: Install Erlang/OTP and Elixir
	uses: erlef/setup-beam@v1
	with:
	otp-version: ${{ matrix.pair.otp }}
	elixir-version: ${{ matrix.pair.elixir }}
	version-type: strict

	- name: Cache Mix dependencies
	uses: actions/cache@v3
	with:
	path: \|
	deps
	_build
	key: \|
	${{ runner.os }}-mix-${{ matrix.pair.elixir }}-${{ matrix.pair.otp }}-${{ hashFiles('**/mix.lock') }}
	restore-keys: \|
	${{ runner.os }}-mix-${{ matrix.pair.elixir }}-${{ matrix.pair.otp }}-

	- name: Fetch Mix dependencies (and check mix.lock)
	run: mix deps.get --check-locked

	- name: Check for formatted files
	run: mix format --check-formatted
	if: ${{ matrix.lint }}

	- name: Check for unused dependencies
	run: mix deps.unlock --check-unused
	if: ${{ matrix.lint }}

	- name: Compile Mix dependencies
	run: mix deps.compile

	- name: Check for compilation warnings
	run: mix compile --warnings-as-errors
	if: ${{ matrix.lint }}

	- run: mix test
	if: ${{ !matrix.coverage }}

	- run: mix coveralls.github
	if: ${{ matrix.coverage }}

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