mix.exs

defmodule ExHal.Mixfile do
  use Mix.Project

  def project do
    [
      app: :exhal,
      description: "Use HAL APIs with ease",
      version: "8.2.0",
      elixir: "~> 1.6",
      test_coverage: [tool: ExCoveralls],
      preferred_cli_env: [coveralls: :test, "coveralls.detail": :test, "coveralls.post": :test],
      deps: deps(),
      package: package()
    ]
  end

  def application do
    [applications: [:logger, :poison, :uri_template, :httpoison]]
  end

  defp deps do
    [
      {:poison, "~> 2.2 or ~> 3.0"},
      {:uri_template, "~> 1.0"},
      {:httpoison, "~> 1.0"},
      {:odgn_json_pointer, ">= 1.0.0 and < 4.0.0", app: false},
      {:expat, "~> 1.0"},

      {:earmark, ">= 0.0.0", only: :dev},
      {:ex_doc, "~> 0.11", only: :dev},
      {:dialyxir, "~> 0.3", only: :dev, runtime: false},

      {:exvcr, "~> 0.10.3", only: :test},
      {:excoveralls, "~> 0.4", only: :test},
      {:mox, "~> 0.3", only: :test},
      {:stream_data, "~> 0.1", only: :test}
    ]
    |> dep_version_overrides
  end

  defp package do
    [
      licenses: ["http://opensource.org/licenses/MIT"],
      maintainers: ["Peter Williams"],
      links: %{homepage: "http://github.com/pezra/exhal"}
    ]
  end

  # For testing with continuous integration systems, it is possible to force
  # the dependency version on packages for which we allow more than one version.
  #
  # For example, say we want to test with two versions of the 'ExWidget' package.
  # The deps may look like this:
  # defp deps do
  #   [ ..., {:ex_widget, "~> 1.5 or ~> 2.2"}, ... ]
  # end
  #
  # Step 1: Add :ex_widget to the @overridable_deps list (below)
  # Step 2: Set the environment variable EXHAL_EX_WIDGET_VERSION before compiling, e.g.
  #   EXHAL_EX_WIDGET_VERSION=2.2.3 mix do deps.get, deps.compile
  #   EXHAL_EX_WIDGET_VERSION="~> 1.5" mix do deps.get, deps.comile

  @overridable_deps [:poison, :httpoison]
  defp dep_version_overrides(deps_list) do
    @overridable_deps
    |> Enum.map(&{&1, env_var_value_for_dep(&1)})
    |> Enum.reduce(deps_list, &override_dep/2)
  end

  defp env_var_value_for_dep(dep_atom) do
    dep_str = dep_atom |> Atom.to_string() |> String.upcase()
    System.get_env("EXHAL_#{dep_str}_VERSION")
  end

  defp override_dep({_package, nil}, deps_list), do: deps_list

  defp override_dep({package, version}, deps_list) do
    Enum.reject(deps_list, fn dep -> elem(dep, 0) == package end) ++ [{package, version}]
  end
end