Added more settings methods; Hooked up initial settings runner to app boot

.iex.exs

@@ -11,6 +11,7 @@ alias Pinchflat.Tasks
 alias Pinchflat.Media
 alias Pinchflat.Profiles
 alias Pinchflat.Sources
+alias Pinchflat.Settings
 
 alias Pinchflat.MediaClient.{SourceDetails, MediaDownloader}
 alias Pinchflat.Metadata.{Zipper, ThumbnailFetcher}

lib/pinchflat/application.ex

@@ -10,6 +10,8 @@ defmodule Pinchflat.Application do
     children = [
       PinchflatWeb.Telemetry,
       Pinchflat.Repo,
+      # {Task, &run_startup_tasks/0},
+      Pinchflat.StartupTasks,
       {Oban, Application.fetch_env!(:pinchflat, Oban)},
       {DNSCluster, query: Application.get_env(:pinchflat, :dns_cluster_query) || :ignore},
       {Phoenix.PubSub, name: Pinchflat.PubSub},

lib/pinchflat/settings.ex

@@ -19,7 +19,8 @@ defmodule Pinchflat.Settings do
 
   @doc """
   Creates or updates a setting, returning the parsed value.
-  Raises if an unsupported datatype is used.
+  Raises if an unsupported datatype is used. Optionally allows
+  specifying the datatype.
 
   Returns value in type of `Ecto.Enum.mappings(Setting, :datatype)`
   """
@@ -46,6 +47,24 @@ defmodule Pinchflat.Settings do
     |> read_setting()
   end
 
+  @doc """
+  Attempts to find a setting by name or creates a setting with value
+  if one doesn't exist, returning the parsed value. Optionally allows
+  specifying the datatype.
+
+  Returns value in type of `Ecto.Enum.mappings(Setting, :datatype)`
+  """
+  def fetch!(name, value) do
+    fetch!(name, value, infer_datatype(value))
+  end
+
+  def fetch!(name, value, datatype) do
+    case Repo.get_by(Setting, name: to_string(name)) do
+      nil -> create_setting!(name, value, datatype)
+      setting -> read_setting(setting)
+    end
+  end
+
   defp change_setting(setting, attrs) do
     Setting.changeset(setting, attrs)
   end

lib/pinchflat/startup_tasks.ex

@@ -0,0 +1,36 @@
+defmodule Pinchflat.StartupTasks do
+  @moduledoc """
+  This module is responsible for running startup tasks on app boot.
+
+  It's a GenServer because that plays REALLY nicely with the existing
+  Phoenix supervision tree.
+  """
+
+  # restart: :temporary means that this process will never be restarted (ie: will run once and then die)
+  use GenServer, restart: :temporary
+
+  alias Pinchflat.Settings
+
+  def start_link(opts \\ []) do
+    GenServer.start_link(__MODULE__, %{}, opts)
+  end
+
+  @doc """
+  Runs application startup tasks.
+
+  Any code defined here will run every time the application starts. You must
+  make sure that the code is idempotent and safe to run multiple times.
+
+  This is a good place to set up default settings, create initial records, stuff like that
+  """
+  @impl true
+  def init(state) do
+    apply_default_settings()
+
+    {:ok, state}
+  end
+
+  defp apply_default_settings do
+    Settings.fetch!(:onboarding, true)
+  end
+end

test/pinchflat/settings_test.exs

@@ -4,25 +4,32 @@ defmodule Pinchflat.SettingsTest do
   alias Pinchflat.Settings
   alias Pinchflat.Settings.Setting
 
+  # NOTE: We're treating some of these tests differently
+  # than in other modules because certain settings
+  # are always created on app boot (including in the test env),
+  # so we can't treat these like a clean slate.
+
   describe "list_settings/0" do
     test "returns all settings" do
       Settings.set!("foo", "bar")
-      assert [_] = Settings.list_settings()
+      results = Settings.list_settings()
+
+      assert Enum.all?(results, fn setting -> match?(%Setting{}, setting) end)
     end
   end
 
   describe "set/2" do
     test "creates a new setting if one does not exist" do
-      assert Repo.aggregate(Setting, :count, :id) == 0
+      original = Repo.aggregate(Setting, :count, :id)
       Settings.set!("foo", "bar")
-      assert Repo.aggregate(Setting, :count, :id) == 1
+      assert Repo.aggregate(Setting, :count, :id) == original + 1
     end
 
     test "updates an existing setting if one exists" do
       Settings.set!("foo", "bar")
-      assert Repo.aggregate(Setting, :count, :id) == 1
+      original = Repo.aggregate(Setting, :count, :id)
       Settings.set!("foo", "baz")
-      assert Repo.aggregate(Setting, :count, :id) == 1
+      assert Repo.aggregate(Setting, :count, :id) == original
       assert Settings.get!("foo") == "baz"
     end
 
@@ -78,4 +85,24 @@ defmodule Pinchflat.SettingsTest do
       end
     end
   end
+
+  describe "fetch/2" do
+    test "creates a setting if one doesn't exist" do
+      original = Repo.aggregate(Setting, :count, :id)
+      assert Settings.fetch!("foo", "bar") == "bar"
+      assert Repo.aggregate(Setting, :count, :id) == original + 1
+    end
+
+    test "returns an existing setting if one does exist" do
+      Settings.set!("foo", "bar")
+
+      assert Settings.fetch!("foo", "baz") == "bar"
+    end
+  end
+
+  describe "fetch/3" do
+    test "allows manual specification of datatype" do
+      assert Settings.fetch!("foo", "true", :boolean) == true
+    end
+  end
 end

test/pinchflat/startup_tasks_test.exs

@@ -0,0 +1,16 @@
+defmodule Pinchflat.StartupTasksTest do
+  use Pinchflat.DataCase
+
+  alias Pinchflat.Settings
+
+  # Since this runs on app boot (even in the test env),
+  # any actions in the `init/1` function will already have
+  # run. So we can only test the side effects of those actions,
+  # rather than the actions themselves.
+
+  describe "apply_default_settings" do
+    test "sets default settings" do
+      assert Settings.get!(:onboarding) == true
+    end
+  end
+end