CaptureLogger

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CaptureLogger is variant of ExUnit.CaptureLog that allows specification of a variant formatter to be specified.

Usage

CaptureLogger is intended to be used in the same way as ExUnit.CaptureLog. Because it uses a different capture server than ExUnit.CaptureLog, it is necessary to start the CaptureLogger server in test/test_helper.exs:

ExUnit.start()
CaptureLogger.start()

Once done, CaptureLogger can be imported the same as ExUnit.CaptureLog and used with a custom formatter:

defmodule AssertionTest do
  use ExUnit.Case

  alias LoggerJSON.Formatters.Basic
  import CaptureLogger
  require Logger

  test "example" do
    {result, log} =
      with_log([formatter: Basic.new()], fn ->
        Logger.error("log msg")
        2 + 2
      end)

    assert result == 4
    assert Jason.decode!(log)["message"] == "log msg"
  end

  test "check multiple captures concurrently" do
    fun = fn ->
      for msg <- ["hello", "hi"] do
        log = assert capture_log(
          [formatter: Basic],
          fn -> Logger.error(msg) end
        )
        assert Jason.decode!(log)["message"] == msg
      end

      Logger.debug("testing")
    end

    assert capture_log([formatter: Basic],fun) =~ "hello"
    assert capture_log([formatter: Basic], fun) =~ "\"message\":\"testing\""
  end
end

Installation

CaptureLogger can be installed by adding capture_logger to your list of dependencies in mix.exs:

def deps do
  [
    {:capture_logger, "~> 1.0"}
  ]
end

Documentation is found on HexDocs.

Semantic Versioning

CaptureLogger follows Semantic Versioning 2.0.