From fb6f9f6888e8780b2251c111cb7f07f3ebe4be60 Mon Sep 17 00:00:00 2001
From: Phil Chen <06fahchen@gmail.com>
Date: Sat, 17 Jun 2023 10:35:45 +0800
Subject: [PATCH] fix: storage or registry can be nil

---
 lib/workflow_metal/application/supervisor.ex | 16 ++++++++++------
 lib/workflow_metal/registration/adapter.ex   |  2 +-
 lib/workflow_metal/storage/adapter.ex        |  2 +-
 3 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/lib/workflow_metal/application/supervisor.ex b/lib/workflow_metal/application/supervisor.ex
index fb981bd..1ac76d1 100644
--- a/lib/workflow_metal/application/supervisor.ex
+++ b/lib/workflow_metal/application/supervisor.ex
@@ -25,12 +25,16 @@ defmodule WorkflowMetal.Application.Supervisor do
 
     config_child_spec = config_child_spec(application, config)
 
-    children = [
-      config_child_spec,
-      registry_child_spec,
-      storage_child_spec,
-      {WorkflowMetal.Application.WorkflowsSupervisor, application}
-    ]
+    children =
+      Enum.reject(
+        [
+          config_child_spec,
+          registry_child_spec,
+          storage_child_spec,
+          {WorkflowMetal.Application.WorkflowsSupervisor, application}
+        ],
+        &is_nil/1
+      )
 
     Supervisor.init(children, strategy: :one_for_one)
   end
diff --git a/lib/workflow_metal/registration/adapter.ex b/lib/workflow_metal/registration/adapter.ex
index 12294a4..82cd837 100644
--- a/lib/workflow_metal/registration/adapter.ex
+++ b/lib/workflow_metal/registration/adapter.ex
@@ -21,7 +21,7 @@ defmodule WorkflowMetal.Registration.Adapter do
   Return a supervisor spec for the registry
   """
   @callback child_spec(application, config) ::
-              {:ok, :supervisor.child_spec() | {module, term} | module, adapter_meta}
+              {:ok, :supervisor.child_spec() | {module, term} | module | nil, adapter_meta}
 
   @doc """
   Return a `:via` tuple to route a message to a process by its registered name
diff --git a/lib/workflow_metal/storage/adapter.ex b/lib/workflow_metal/storage/adapter.ex
index 1a23181..6f46782 100644
--- a/lib/workflow_metal/storage/adapter.ex
+++ b/lib/workflow_metal/storage/adapter.ex
@@ -13,7 +13,7 @@ defmodule WorkflowMetal.Storage.Adapter do
   Return a child spec for the storage
   """
   @callback child_spec(application, config) ::
-              {:ok, :supervisor.child_spec() | {module, term} | module, adapter_meta}
+              {:ok, :supervisor.child_spec() | {module, term} | module | nil, adapter_meta}
 
   # Workflow