dont' start the repo unless necessary

config/test.exs

@@ -23,6 +23,7 @@ config :logger, level: :warn
 
 config :matrix_app_service,
   internal_supervisor: true,
+  internal_repo: true,
   transaction_adapter: MatrixAppService.TestTransactionAdapter,
   room_adapter: MatrixAppService.TestRoomAdapter,
   user_adapter: MatrixAppService.TestUserAdapter,

lib/matrix_app_service/application.ex

@@ -18,16 +18,20 @@ defmodule MatrixAppService.Application do
     ]
 
     children =
-      if start_endpoint?() do
-        [
-          # MatrixAppServiceWeb.Endpoint
-          {MatrixAppServiceWeb.Endpoint, endpoint_config()},
+      if start_endpoint?(),
+        do: [
+          {MatrixAppServiceWeb.Endpoint, endpoint_config()}
+          | children
+        ],
+        else: children
+
+    children =
+      if start_repo?(),
+        do: [
           MatrixAppService.Repo
           | children
-        ]
-      else
-        children
-      end
+        ],
+        else: children
 
     # See https://hexdocs.pm/elixir/Supervisor.html
     # for other strategies and supported options
@@ -49,6 +53,10 @@ defmodule MatrixAppService.Application do
     Application.get_env(:matrix_app_service, :internal_supervisor, false)
   end
 
+  def start_repo?() do
+    Application.get_env(:matrix_app_service, :internal_repo, false)
+  end
+
   def endpoint_config() do
     [
       transaction_adapter: Application.fetch_env!(:matrix_app_service, :transaction_adapter),