PowerAssert

PowerAssert for Elixir.

Example test is here:

test "Enum.at should return the element at the given index" do
  array = [1, 2, 3]; index = 2; two = 2
  assert array |> Enum.at(index) == two
end

And the result is like the following:

  1) test Enum.at should return the element at the given index (PowerAssertTest)

     array |> Enum.at(index) == two
     |             |  |         |
     |             |  |         2
     |             |  2
     |             3
     [1, 2, 3]

Enjoy !

Dependencies

• ExUnit

Installation

# add dependencies in mix.exs
defp deps do
  [
    {:power_assert, "~> 0.0.1"}
  ]
end

# and fetch
$ mix deps.get

How to use

# replace `use ExUnit.Case` into `use PowerAssert` in your test code

## before
defmodule YourAwesomeTest do
  use ExUnit.Case  # <-- **HERE**
end

## after
defmodule YourAwesomeTest do
  use PowerAssert  # <-- **REPLACED**
end

when ExUnit.CaseTemplate

# replace `use ExUnit.CaseTemplate` into `use PowerAssert.CaseTemplate` in your test code

## before
defmodule YourAwesomeTest do
  use ExUnit.CaseTemplate       # <-- **HERE**
end

## after
defmodule YourAwesomeTest do
  use PowerAssert.CaseTemplate  # <-- **REPLACED**
end

useful command to replace use ExUnit.CaseTemplate and use ExUnit.Case

$ git grep -l 'use ExUnit\.CaseTemplate' | xargs sed -i.bak -e 's/use ExUnit\.CaseTemplate/use PowerAssert.CaseTemplate/g'
$ git grep -l 'use ExUnit\.Case' | xargs sed -i.bak -e 's/use ExUnit\.Case/use PowerAssert/g'

API

assert(expression, message \\ nil)

TODO

• ExUnit.CaseTemplate with using function
• support assert [one] = [two]
  • currently rely on ExUnit.Assertions.assert/1
• and more we've not yet noticed

Limitation

• NOT SUPPORTED
  • match expression ex: assert List.first(x = [false])
  • fn expression ex: assert fn(x) -> x == 1 end.(2)
  • :: expression ex: << x :: bitstring >>
    • this means string interpolations also unsupported ex: "#{x} hoge"
  • sigil expression ex: ~w(hoge fuga)
  • quote arguments ex: assert quote(@opts, do: :hoge)
  • case expression
  • get_and_update_in/2, put_in/2, update_in/2, for/1
  • <<>> expression includes attributes <<@x, "y">>; <<x :: binary, "y">>
  • __MODULE__.Foo
  • many macros maybe caught error...

License

Distributed under the Apache 2 License.

Check LICENSE files for more information.