1 files changed, 97 insertions, 0 deletions
diff --git a/test/elixir/lib/setup.ex b/test/elixir/lib/setup.ex
new file mode 100644
index 000000000..037988521
--- /dev/null
+++ b/test/elixir/lib/setup.ex
@@ -0,0 +1,97 @@
+defmodule Couch.Test.Setup do
+  @moduledoc """
+  Allows to chain setup functions.
+  Example of using:
+
+  ```
+    alias Couch,Test.Utils
+    def with_db_name(context, setup) do
+      setup =
+        setup
+          |> Step.Start.new(:start, extra_apps: [:chttpd])
+          |> Step.User.new(:admin, roles: [:server_admin])
+          |> Setup.run()
+
+      context =
+        Map.merge(context, %{
+          db_name: Utils.random_name("db")
+          base_url: setup |> Setup.get(:start) |> Step.Start.clustered_url(),
+          user: setup |> Setup.get(:admin) |> Step.User.name()
+        })
+      {context, setup}
+    end
+
+    @tag setup: &__MODULE__.with_db_name/2
+      test "Create", %{db_name: db_name, user: user} do
+        ...
+      end
+  ```
+  """
+  import ExUnit.Callbacks, only: [on_exit: 1]
+  import ExUnit.Assertions, only: [assert: 2]
+  require Logger
+
+  alias Couch.Test.Setup
+  alias Couch.Test.Setup.Step
+  defstruct stages: [], by_type: %{}, state: %{}
+
+  def step(%Setup{stages: stages} = setup, id, step) do
+    %{setup | stages: [{id, step} | stages]}
+  end
+
+  defp setup_step({id, step}, %Setup{state: state, by_type: by_type} = setup) do
+    %module{} = step
+    # credo:disable-for-next-line Credo.Check.Warning.LazyLogging
+    Logger.debug("Calling 'setup/2' for '#{module}'")
+    step = module.setup(setup, step)
+    state = Map.put(state, id, step)
+    by_type = Map.update(by_type, module, [id], fn ids -> [id | ids] end)
+    on_exit(fn ->
+      # credo:disable-for-next-line Credo.Check.Warning.LazyLogging
+      Logger.debug("Calling 'teardown/3' for '#{module}'")
+      try do
+        module.teardown(setup, step)
+        :ok
+      catch
+        _ -> :ok
+        _, _ -> :ok
+      end
+    end)
+    {{id, step}, %{setup | state: state, by_type: by_type}}
+  end
+
+  def run(%Setup{stages: stages} = setup) do
+    {stages, setup} = stages
+      |> Enum.reverse
+      |> Enum.map_reduce(setup, &setup_step/2)
+    %{setup | stages: stages}
+  end
+
+  def setup(ctx) do
+    Map.get(ctx, :__setup)
+  end
+
+  def setup(ctx, setup_fun) do
+    setup = %Setup{} |> Step.Config.new(:test_config, config_file: nil)
+    {ctx, setup} = setup_fun.(ctx, setup)
+    assert not Map.has_key?(ctx, :__setup), "Key `__setup` is reserved for internal purposes"
+    Map.put(ctx, :__setup, setup)
+  end
+
+  def completed?(%Setup{by_type: by_type}, step) do
+    Map.has_key?(by_type, step)
+  end
+
+  def all_for(%Setup{by_type: by_type, state: state}, step_module) do
+    Map.take(state, by_type[step_module] || [])
+  end
+
+  def reduce_for(setup, step_module, acc, fun) do
+    Enum.reduce(all_for(setup, step_module), acc, fun)
+  end
+
+  def get(%Setup{state: state}, id) do
+    state[id]
+  end
+
+end
+\ No newline at end of file