This library is meant to provide an ergonomic way to pattern match and bind data in complex types such as maps and structs during testing.
The package can be installed by adding exmatch to your list of dependencies in mix.exs:
defp deps do
[
{:exmatch, "~> 0.16.0", only: [:dev, :test]}
]
endThe library depends on ExUnit.AssertionError and therefore is meant to be used only in testing.
The examples below display ExMatchTest.AssertionError as they are used as doctests. When used in your tests the ExUnit.AssertionError would be used instead. Using plain IEx environment will use basic struct formatter different from ExUnit.CLIFormatter.
iex> ExMatch.match(%{a: 1, b: 2, c: 3}, %{c: 3, a: 2, b: {1, 0}})
** (ExMatchTest.AssertionError)
left: %{a: 1, b: 2}
right: %{a: 2, b: {1, 0}}iex> opts = ExMatch.options([{Decimal, [:match_integer]}])
iex> ExMatch.match([10, eleven, _], [Decimal.new("10"), 11, 12], opts)
iex> eleven == 11
trueiex> eleven = 11
iex> ExMatch.match(%Decimal{coef: ^eleven, exp: 1 - 1, sign: 1}, Decimal.add(1, eleven))
** (ExMatchTest.AssertionError)
left: %Decimal{coef: ^eleven = 11}
right: %Decimal{coef: 12}iex> ExMatch.match(%ExMatchTest.Dummy{
...> a: %ExMatchTest.Dummy1{a: 1},
...> b: ~U[2022-02-19 05:10:08.387165Z]
...> }, %ExMatchTest.Dummy{
...> a: %ExMatchTest.Dummy{a: 1},
...> b: Timex.parse!("2022-02-19 14:55:08.387165+09:45", "{ISO:Extended}")
...> })
** (ExMatchTest.AssertionError)
left: %ExMatchTest.Dummy{a: %ExMatchTest.Dummy1{}}
right: %ExMatchTest.Dummy{a: %ExMatchTest.Dummy{}}iex> url = URI.parse("https://elixir-lang.org/")
iex> ExMatch.match(%URI{url | path: path}, URI.parse("https://elixir-lang.org/cases.html"))
iex> path == "/cases.html"
trueiex> url = URI.parse("https://elixir-lang.org/")
iex> ExMatch.match(%URI{url | scheme: "http"}, URI.parse("http://localhost:3000"))
** (ExMatchTest.AssertionError)
left: url = %URI{authority: "elixir-lang.org", host: "elixir-lang.org", path: "/", port: 443}
right: %URI{authority: "localhost:3000", host: "localhost", path: nil, port: 3000}