Test database connection

.tool-versions

@@ -1,2 +1,3 @@
 erlang 26.1.2
-elixir 1.15.7-otp-26
+elixir 1.15.7-otp-26
+rust 1.63.0

lib/mix/tasks/walex.drop.ex

@@ -2,9 +2,7 @@ defmodule Mix.Tasks.Walex.Drop do
   @moduledoc """
   Drops the database
   """
-
   use Mix.Task
-
   alias Mix.Tasks.Walex.Helpers
 
   @test_database "todos_test"

lib/mix/tasks/walex.setup.ex

@@ -2,12 +2,16 @@ defmodule Mix.Tasks.Walex.Setup do
   @moduledoc """
   Creates, migrates and seeds the database
   """
-
   use Mix.Task
-
   alias Mix.Tasks.Walex.Helpers
 
   @test_database "todos_test"
+  @base_configs [
+    hostname: "localhost",
+    username: "postgres",
+    password: "postgres",
+    database: @test_database
+  ]
 
   @shortdoc "Set up test database and tables"
   def run(_) do
@@ -17,14 +21,7 @@ defmodule Mix.Tasks.Walex.Setup do
 
   defp setup_test_database do
     Helpers.create_database(@test_database)
-
-    {:ok, pid} =
-      Postgrex.start_link(
-        hostname: "localhost",
-        username: "postgres",
-        password: "postgres",
-        database: @test_database
-      )
+    {:ok, pid} = Postgrex.start_link(@base_configs)
 
     create_database_logic(pid)
     create_database_tables(pid)

lib/walex/config/config.ex

@@ -2,7 +2,6 @@ defmodule WalEx.Config do
   @moduledoc """
   Configuration
   """
-
   use Agent
 
   alias WalEx.Config.Registry, as: WalExRegistry

lib/walex/replication/server.ex

@@ -39,24 +39,21 @@ defmodule WalEx.Replication.Server do
 
   @impl true
   def handle_connect(state) do
-    temp_slot = "walex_temp_slot_" <> Integer.to_string(:rand.uniform(9_999))
-
-    query = "CREATE_REPLICATION_SLOT #{temp_slot} TEMPORARY LOGICAL pgoutput NOEXPORT_SNAPSHOT;"
+    query =
+      "CREATE_REPLICATION_SLOT #{slot_name(state.app_name)} TEMPORARY LOGICAL pgoutput NOEXPORT_SNAPSHOT;"
 
     {:query, query, %{state | step: :create_slot}}
   end
 
   @impl true
-  def handle_result([%Postgrex.Result{rows: rows} | _results], state = %{step: :create_slot}) do
-    slot_name = rows |> hd |> hd
-
+  def handle_result([%Postgrex.Result{} | _results], state = %{step: :create_slot}) do
     publication =
       state.app_name
       |> WalEx.Config.get_configs([:publication])
       |> Keyword.get(:publication)
 
     query =
-      "START_REPLICATION SLOT #{slot_name} LOGICAL 0/0 (proto_version '1', publication_names '#{publication}')"
+      "START_REPLICATION SLOT #{slot_name(state.app_name)} LOGICAL 0/0 (proto_version '1', publication_names '#{publication}')"
 
     {:stream, query, [], %{state | step: :streaming}}
   end
@@ -83,4 +80,6 @@ defmodule WalEx.Replication.Server do
 
   @epoch DateTime.to_unix(~U[2000-01-01 00:00:00Z], :microsecond)
   defp current_time, do: System.os_time(:microsecond) - @epoch
+
+  defp slot_name(app_name), do: to_string(app_name) <> "_walex"
 end

mix.exs

@@ -15,7 +15,8 @@ defmodule WalEx.MixProject do
       name: "WalEx",
       source_url: "https://github.com/cpursley/walex",
       test_coverage: [tool: ExCoveralls],
-      elixirc_paths: elixirc_paths(Mix.env())
+      elixirc_paths: elixirc_paths(Mix.env()),
+      compilers: compilers()
     ]
   end
 
@@ -43,7 +44,8 @@ defmodule WalEx.MixProject do
       {:ex_doc, "~> 0.31.1", only: :dev, runtime: false},
       {:sobelow, "~> 0.12", only: [:dev, :test], runtime: false},
       {:credo, "~> 1.7.3", only: [:dev, :test], runtime: false},
-      {:excoveralls, "~> 0.10", only: [:dev, :test], runtime: false}
+      {:excoveralls, "~> 0.10", only: [:dev, :test], runtime: false},
+      {:rambo, "~> 0.3.4", only: [:dev, :test], runtime: false}
     ]
   end
 
@@ -76,4 +78,12 @@ defmodule WalEx.MixProject do
 
   defp elixirc_paths(:test), do: ["lib", "test/support"]
   defp elixirc_paths(_), do: ["lib"]
+
+  defp compilers do
+    unless Mix.env() == :prod do
+      Mix.compilers() ++ [:rambo]
+    else
+      Mix.compilers()
+    end
+  end
 end

mix.lock

@@ -37,6 +37,7 @@
   "plug_crypto": {:hex, :plug_crypto, "2.0.0", "77515cc10af06645abbfb5e6ad7a3e9714f805ae118fa1a70205f80d2d70fe73", [:mix], [], "hexpm", "53695bae57cc4e54566d993eb01074e4d894b65a3766f1c43e2c61a1b0f45ea9"},
   "postgrex": {:hex, :postgrex, "0.17.4", "5777781f80f53b7c431a001c8dad83ee167bcebcf3a793e3906efff680ab62b3", [:mix], [{:db_connection, "~> 2.1", [hex: :db_connection, repo: "hexpm", optional: false]}, {:decimal, "~> 1.5 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:table, "~> 0.1.0", [hex: :table, repo: "hexpm", optional: true]}], "hexpm", "6458f7d5b70652bc81c3ea759f91736c16a31be000f306d3c64bcdfe9a18b3cc"},
   "protobuf": {:hex, :protobuf, "0.12.0", "58c0dfea5f929b96b5aa54ec02b7130688f09d2de5ddc521d696eec2a015b223", [:mix], [{:jason, "~> 1.2", [hex: :jason, repo: "hexpm", optional: true]}], "hexpm", "75fa6cbf262062073dd51be44dd0ab940500e18386a6c4e87d5819a58964dc45"},
+  "rambo": {:hex, :rambo, "0.3.4", "8962ac3bd1a633ee9d0e8b44373c7913e3ce3d875b4151dcd060886092d2dce7", [:mix], [], "hexpm", "0cc54ed089fbbc84b65f4b8a774224ebfe60e5c80186fafc7910b3e379ad58f1"},
   "ranch": {:hex, :ranch, "1.8.0", "8c7a100a139fd57f17327b6413e4167ac559fbc04ca7448e9be9057311597a1d", [:make, :rebar3], [], "hexpm", "49fbcfd3682fab1f5d109351b61257676da1a2fdbe295904176d5e521a2ddfe5"},
   "req": {:hex, :req, "0.4.8", "2b754a3925ddbf4ad78c56f30208ced6aefe111a7ea07fb56c23dccc13eb87ae", [:mix], [{:brotli, "~> 0.3.1", [hex: :brotli, repo: "hexpm", optional: true]}, {:ezstd, "~> 1.0", [hex: :ezstd, repo: "hexpm", optional: true]}, {:finch, "~> 0.9", [hex: :finch, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}, {:mime, "~> 1.6 or ~> 2.0", [hex: :mime, repo: "hexpm", optional: false]}, {:nimble_csv, "~> 1.0", [hex: :nimble_csv, repo: "hexpm", optional: true]}, {:plug, "~> 1.0", [hex: :plug, repo: "hexpm", optional: true]}], "hexpm", "7146e51d52593bb7f20d00b5308a5d7d17d663d6e85cd071452b613a8277100c"},
   "retry": {:hex, :retry, "0.18.0", "dc58ebe22c95aa00bc2459f9e0c5400e6005541cf8539925af0aa027dc860543", [:mix], [], "hexpm", "9483959cc7bf69c9e576d9dfb2b678b71c045d3e6f39ab7c9aa1489df4492d73"},

test/support/test_helpers.ex

@@ -1,5 +1,11 @@
 defmodule WalEx.Support.TestHelpers do
-  def find_worker_pid(supervisor_pid, child_module) do
+  require Logger
+
+  def tap_debug(to_tap, label) do
+    to_tap |> tap(&Logger.debug(label <> inspect(&1)))
+  end
+
+  def find_child_pid(supervisor_pid, child_module) do
     supervisor_pid
     |> Supervisor.which_children()
     |> find_pid(child_module)
@@ -10,6 +16,59 @@ defmodule WalEx.Support.TestHelpers do
     pid
   end
 
+  def get_database_pid(supervisor_pid) do
+    find_child_pid(supervisor_pid, DBConnection.ConnectionPool)
+  end
+
+  def start_database(configs) do
+    case Postgrex.start_link(configs) do
+      {:ok, conn} ->
+        Logger.info("Database is running.")
+
+        {:ok, conn}
+
+      {:error, {:already_started, conn}} ->
+        Logger.info("Database is already running.")
+
+        {:ok, conn}
+
+      {:error, reason} ->
+        Logger.error("Error connecting to the database. Reason: #{inspect(reason)}")
+
+        {:error, reason}
+    end
+  end
+
+  def terminate_database_connection(database_pid, username) do
+    query =
+      "SELECT pg_terminate_backend(pg_backend_pid()) FROM pg_stat_activity WHERE usename = $1"
+
+    Postgrex.query(database_pid, query, [username])
+  end
+
+  def wait_for_restart do
+    Logger.debug("waiting")
+    :timer.sleep(3000)
+    Logger.debug("done waiting")
+  end
+
+  def query(pid, query) do
+    pid
+    |> Postgrex.query!(query, [])
+    |> map_rows_to_columns()
+  end
+
+  defp map_rows_to_columns(%Postgrex.Result{columns: columns, rows: rows}) do
+    Enum.map(rows, fn row -> Enum.zip(columns, row) |> Map.new() end)
+  end
+
+  def pg_replication_slots(database_pid) do
+    pg_replication_slots_query =
+      "SELECT slot_name, slot_type, active FROM \"pg_replication_slots\";"
+
+    query(database_pid, pg_replication_slots_query)
+  end
+
   def update_user(database_pid) do
     update_user = """
       UPDATE \"user\" SET age = 30 WHERE id = 1