Hello All,
I am reading “Metaprogramming Elixir” by C. McCord and I am wondering how to enhance its chapter 2 example on the ExUnit test macro (see below). I would like to be able to access a “context” variable in test call, as in
> test "bla", context do
> .... context[var] ....
> end
However, the current unquote(test_block) is definitely not sufficient. I guess that some Macro.escape could help, but …
The following code is given by Chris for the simple test macro (without any context) :
> defmodule Assertion do
> defmacro __using__(_options) do
> quote do
> import unquote(__MODULE__)
> Module.register_attribute __MODULE__, :tests, accumulate: true
> @before_compile unquote(__MODULE__)
> end
> end
>
> defmacro __before_compile__(_env) do
> quote do
> def run, do: Assertion.Test.run(@tests, __MODULE__)
> end
> end
>
> defmacro test(description, do: test_block) do
> test_func = String.to_atom(description)
> quote do
> @tests {unquote(test_func), unquote(description)}
> def unquote(test_func)(), do: unquote(test_block)
> end
> end
>
> defmacro assert({operator, _, [lhs, rhs]}) do
> quote bind_quoted: [operator: operator, lhs: lhs, rhs: rhs] do
> Assertion.Test.assert(operator, lhs, rhs)
> end
> end
> end
Can you help me on improving this exemple by introducing the capability to access data from inside the test macro via a declared “context” variable in the test call as in the ExUnit framework ?
Thanks a lot.
Laurent
