From 3f2c43e6d3e560d9a66e77af8d4fb23dc8f09a30 Mon Sep 17 00:00:00 2001
From: Matt Beanland <beanland@live.com.au>
Date: Fri, 8 May 2026 21:15:39 +0930
Subject: [PATCH] igniter

---
 README.md                      | 15 +++++--
 lib/mix/tasks/diffo.install.ex | 79 ++++++++++++++++++++++++++++++++++
 mix.exs                        |  2 +-
 3 files changed, 91 insertions(+), 5 deletions(-)
 create mode 100644 lib/mix/tasks/diffo.install.ex

diff --git a/README.md b/README.md
index 0b19036..95dd7da 100644
--- a/README.md
+++ b/README.md
@@ -34,18 +34,25 @@ Diffo is especially suited for use in organisations with loosely coupled 'entity
 
 ## Installation
 
-If [available in Hex](https://hex.pm/docs/publish), the package can be installed
-by adding `diffo` to your list of dependencies in `mix.exs`:
+The recommended way to install Diffo is with [Igniter](https://hexdocs.pm/igniter):
+
+```bash
+mix igniter.install diffo
+```
+
+This will add the dependency, configure Neo4j (via `ash_neo4j`), register the custom expression, and set up the Spark formatter.
+
+Alternatively, add `diffo` to your list of dependencies in `mix.exs` manually:
 
 ```elixir
 def deps do
   [
-    {:diffo, "~> 0.1.6"}
+    {:diffo, "~> 0.2.1"}
   ]
 end
 ```
 
-You should need [Neo4j](https://github.com/neo4j/neo4j) available. We recommend the Neo4j Community 5 latest, available at [Neo4j Deploymnent Centre](https://neo4j.com/deployment-center/) which can be installed locally. You can also configure connection to a cloud based database service such as [Neo4j AuraDB](https://neo4j.com/product/auradb/).
+You will need [Neo4j](https://github.com/neo4j/neo4j) available. We recommend the Neo4j Community 5 latest, available at [Neo4j Deploymnent Centre](https://neo4j.com/deployment-center/) which can be installed locally. You can also configure connection to a cloud based database service such as [Neo4j AuraDB](https://neo4j.com/product/auradb/).
 
 ## Tutorial
 
diff --git a/lib/mix/tasks/diffo.install.ex b/lib/mix/tasks/diffo.install.ex
new file mode 100644
index 0000000..11d45a0
--- /dev/null
+++ b/lib/mix/tasks/diffo.install.ex
@@ -0,0 +1,79 @@
+# SPDX-FileCopyrightText: 2025 diffo contributors <https://github.com/diffo-dev/diffo/graphs.contributors>
+#
+# SPDX-License-Identifier: MIT
+
+defmodule Mix.Tasks.Diffo.Install.Docs do
+  @moduledoc false
+
+  def short_doc, do: "Installs Diffo"
+  def example, do: "mix igniter.install diffo"
+
+  def long_doc do
+    """
+    #{short_doc()}
+
+    ## Example
+
+    ```bash
+    #{example()}
+    ```
+    """
+  end
+end
+
+if Code.ensure_loaded?(Igniter) do
+  defmodule Mix.Tasks.Diffo.Install do
+    @shortdoc "#{__MODULE__.Docs.short_doc()}"
+    @moduledoc __MODULE__.Docs.long_doc()
+
+    use Igniter.Mix.Task
+
+    @impl Igniter.Mix.Task
+    def info(_argv, _composing_task) do
+      %Igniter.Mix.Task.Info{
+        group: :ash,
+        installs: [{:ash_neo4j, "~> 0.5"}],
+        example: __MODULE__.Docs.example()
+      }
+    end
+
+    @impl Igniter.Mix.Task
+    def igniter(igniter) do
+      igniter
+      |> Igniter.Project.Formatter.import_dep(:diffo)
+      |> Spark.Igniter.prepend_to_section_order(
+        :"Ash.Resource",
+        [:specification, :features, :characteristics]
+      )
+      |> Igniter.Project.Config.configure(
+        "config.exs",
+        :ash,
+        [:custom_expressions],
+        [Diffo.Unwrap.AshCustomExpression],
+        updater: fn zipper ->
+          Igniter.Code.List.prepend_new_to_list(
+            zipper,
+            quote(do: Diffo.Unwrap.AshCustomExpression)
+          )
+        end
+      )
+    end
+  end
+else
+  defmodule Mix.Tasks.Diffo.Install do
+    @shortdoc "#{__MODULE__.Docs.short_doc()} | Install `igniter` to use"
+    @moduledoc __MODULE__.Docs.long_doc()
+
+    use Mix.Task
+
+    def run(_argv) do
+      Mix.shell().error("""
+      The task 'diffo.install' requires igniter. Please install igniter and try again.
+
+      For more information, see: https://hexdocs.pm/igniter/readme.html#installation
+      """)
+
+      exit({:shutdown, 1})
+    end
+  end
+end
diff --git a/mix.exs b/mix.exs
index c719f05..54c61f3 100644
--- a/mix.exs
+++ b/mix.exs
@@ -99,7 +99,7 @@ defmodule Diffo.MixProject do
       {:ash_outstanding, "~> 0.2.3"},
       {:ash_jason, "~> 3.0"},
       {:ash_state_machine, "~> 0.2.12"},
-      {:ash_neo4j, ash_neo4j_version("~> 0.4.1")},
+      {:ash_neo4j, ash_neo4j_version("~> 0.5")},
       {:bolty, ">= 0.0.12"},
       {:ash, ash_version("~> 3.0 and >= 3.24.2")},
       {:uuid, "~> 1.1"},