Fix postgres errors when running tests

config/test.exs

@@ -45,3 +45,6 @@ config :mv, :token_signing_secret, "test_secret_key_for_ash_authentication_token
 config :mv, :session_identifier, :unsafe
 
 config :mv, :require_token_presence_for_authentication, false
+
+# Enable SQL Sandbox for async LiveView tests
+config :mv, :sql_sandbox, true

lib/mv_web/endpoint.ex

@@ -39,6 +39,11 @@ defmodule MvWeb.Endpoint do
     plug Phoenix.Ecto.CheckRepoStatus, otp_app: :mv
   end
 
+  # Enable Ecto SQL Sandbox in test environment for async tests
+  if Application.compile_env(:mv, :sql_sandbox) do
+    plug Phoenix.Ecto.SQL.Sandbox
+  end
+
   plug Phoenix.LiveDashboard.RequestLogger,
     param_key: "request_logger",
     cookie_key: "request_logger"

test/support/conn_case.ex

@@ -123,7 +123,13 @@ defmodule MvWeb.ConnCase do
   end
 
   setup tags do
-    Mv.DataCase.setup_sandbox(tags)
-    {:ok, conn: Phoenix.ConnTest.build_conn()}
+    pid = Mv.DataCase.setup_sandbox(tags)
+
+    conn = Phoenix.ConnTest.build_conn()
+    # Set metadata for Phoenix.Ecto.SQL.Sandbox plug to allow LiveView processes
+    # to share the test's database connection in async tests
+    conn = Plug.Conn.put_private(conn, :ecto_sandbox, pid)
+
+    {:ok, conn: conn}
   end
 end

test/support/data_case.ex

@@ -34,10 +34,12 @@ defmodule Mv.DataCase do
 
   @doc """
   Sets up the sandbox based on the test tags.
+  Returns the owner pid for use with Phoenix.Ecto.SQL.Sandbox.
   """
   def setup_sandbox(tags) do
     pid = Ecto.Adapters.SQL.Sandbox.start_owner!(Mv.Repo, shared: not tags[:async])
     on_exit(fn -> Ecto.Adapters.SQL.Sandbox.stop_owner(pid) end)
+    pid
   end
 
   @doc """