release 0.4.1

Closes #170 — Diffo.Provider.Changes.Define / Relate / Assign change modules
wrap the standard after-action plumbing and reload via the resource's primary
:read action.

Closes #171 — BaseCharacteristic synthesises :create and :update actions
from declared public attributes via a new Spark transformer in
Diffo.Provider.Characteristic.Extension. Consumers may still override.

Closes #169 — BaseInstance loads :typed_characteristics and :pool_characteristics
calculations by default; the jason customize merges them into the
serviceCharacteristic / resourceCharacteristic JSON array so typed
BaseCharacteristic records and AssignableCharacteristic pool records surface
at the TMF level.

767 tests passing (90 doctests + 677). mix format clean, reuse lint clean.

Author: matt-beanland

AGENTS.md

@@ -331,8 +331,9 @@ not. Add any useful hypotheses as a follow-up comment on the issue, then leave i
 - Using `characteristic :name, Diffo.Provider.AssignableCharacteristic` for pools — use `pools do / pool :name, :thing / end` instead.
 - Using the removed `AssignableValue` TypedStruct — it no longer exists; use `pools do`.
 - Calling `Assigner.assign/4` when a `pools do` declaration exists — prefer `Assigner.assign/3` which looks up the thing automatically.
-- Forgetting to call `Pool.update_pools/3` in `:define` actions when the resource has `pools do` — pool bounds (`first`, `last`, `algorithm`) are set here.
-- Calling `Assigner.assign/3` on an instance that is not in the correct lifecycle state — the assigner enforces: resource instances must have `resource_state: :operating`; service instances must have `service_state: :active` or `:inactive`. Lifecycle state transitions are an internal domain concern managed by the provider; assignment actions are external-facing. Future: consumer reads may filter out non-`:operating` resources entirely.
+- Hand-writing the `:define` / `:relate` / `:assign_*` after-action plumbing — use `Diffo.Provider.Changes.Define`, `Diffo.Provider.Changes.Relate`, and `{Diffo.Provider.Changes.Assign, pool: :name}` (since 0.4.1). The change modules thread `Characteristic.update_all/3`, `Pool.update_pools/3`, `Relationship.relate_instance/2` and `Assigner.assign/3` together and reload via the resource's primary `:read` action.
+- Hand-writing the `:create` / `:update` accept lists on a `BaseCharacteristic`-derived resource — they are synthesised from the resource's public attributes (since 0.4.1). Declare your own only when you need a narrower accept list.
+- Calling `Assigner.assign/3` on an instance that is not in the correct lifecycle state — the assigner enforces: resource instances must have `resource_state` of `:installing` or `:operating`; service instances must have `service_state` of `:feasibilityChecked`, `:reserved`, `:inactive`, `:active`, or `:suspended` (since 0.4.1). The full lists are exposed via `Assigner.assignable_resource_states/0` and `Assigner.assignable_service_states/0`. Lifecycle state transitions are an internal domain concern managed by the provider; assignment actions are external-facing.
 - Wondering why `Relationship` and `AssignmentRelationship` both have an `alias` attribute with a `[:source_id, :alias]` / `[:target_id, :alias]` identity — alias is a "baby name" given to a relationship slot before (or when) the target is bound. Its full purpose becomes clear alongside the first-order expectation system (see issue #122): the expectation declares the alias for a slot it expects to be filled, and the actual relationship carries the same alias so the two can be matched. Without expectations in place, aliases look like optional metadata; with them, they are the join key between intent and fulfilment.
 - Using `characteristic :pool_name, Diffo.Provider.AssignedToRelationship` — `AssignedToRelationship` no longer exists; use `pools do / pool :name, :thing / end` instead.
 - Querying `Diffo.Provider.Relationship` for assignment records — assignments are stored as `Diffo.Provider.DefinedSimpleRelationship`; access them via `instance.assignments`.

CHANGELOG.md

@@ -11,6 +11,42 @@ See [Conventional Commits](Https://conventionalcommits.org) for commit guideline
 
 <!-- changelog -->
 
+## [v0.4.1](https://github.com/diffo-dev/diffo/compare/v0.4.0...v0.4.1) (2026-05-22)
+
+### Bug Fixes
+
+* **Assigner lifecycle** (#168) — broadened the lifecycle states permitted to make assignments. Services may now assign from `:feasibilityChecked`, `:reserved`, `:inactive`, `:active`, or `:suspended` (was `:active` / `:inactive` only). Resources may now assign from `:installing` or `:operating` (was `:operating` only). `Assigner.assignable_state?/1` exposes the policy directly.
+
+### Features
+
+* **`Diffo.Provider.Changes.Define` / `Relate` / `Assign`** (#170) — change modules that wrap the standard after-action patterns every Instance consumer writes. Replace the hand-written `after_action` body threading `Characteristic.update_all` / `Pool.update_pools` / `Relationship.relate_instance` / `Assigner.assign` together with a one-liner:
+
+  ```elixir
+  update :define do
+    argument :characteristic_value_updates, {:array, :term}
+    change Diffo.Provider.Changes.Define
+  end
+
+  update :relate do
+    argument :relationships, {:array, :struct}
+    change Diffo.Provider.Changes.Relate
+  end
+
+  update :assign_port do
+    argument :assignment, :struct, constraints: [instance_of: Assignment]
+    change {Diffo.Provider.Changes.Assign, pool: :ports}
+  end
+  ```
+
+  Reload happens via the resource's primary `:read` action, so no consumer-specific reader is needed.
+* **BaseCharacteristic auto-generated `:create` / `:update` actions** (#171) — `BaseCharacteristic`-derived resources now get default `:create` and `:update` actions synthesised from their public attributes. `:create` accepts `[:name | <public_attrs>]` with `:instance_id` / `:feature_id` arguments and `manage_relationship` changes; `:update` accepts `<public_attrs>`. Consumers may still declare their own actions to override the defaults.
+* **Typed characteristics and pools in Instance JSON** (#169) — `BaseInstance` now loads two new calculations (`:typed_characteristics`, `:pool_characteristics`) by default and the jason customize merges their values into the `serviceCharacteristic` / `resourceCharacteristic` array. Typed `BaseCharacteristic` records and `AssignableCharacteristic` pool records that were already present in the graph are now visible at the TMF JSON surface.
+
+### Notable Changes
+
+* `Diffo.Provider.Calculations.TypedCharacteristics` and `Diffo.Provider.Calculations.PoolCharacteristics` — new calc modules backing the JSON surfacing for #169.
+* Regression test added for #62 (characteristic update validation) — typed `BaseCharacteristic` updates now reject unknown fields and invalid types through Ash's standard changeset machinery.
+
 ## [v0.4.0](https://github.com/diffo-dev/diffo/compare/v0.3.0...v0.4.0) (2026-05-20)
 
 ### Breaking Changes

lib/diffo/provider/changes/assign.ex

@@ -0,0 +1,56 @@
+# SPDX-FileCopyrightText: 2025 diffo contributors <https://github.com/diffo-dev/diffo/graphs.contributors>
+#
+# SPDX-License-Identifier: MIT
+
+defmodule Diffo.Provider.Changes.Assign do
+  @moduledoc """
+  After-action change for the standard `:assign_*` pattern.
+
+  Performs an assignment for the named pool via `Assigner.assign/3`, then
+  reloads the result via the resource's primary `:read` action.
+
+  ## Usage
+
+      update :assign_port do
+        argument :assignment, :struct, constraints: [instance_of: Assignment]
+        change {Diffo.Provider.Changes.Assign, pool: :ports}
+      end
+
+  ## Options
+
+  - `:pool` (required) — the pool name (atom) declared via `pools do` on the
+    consuming instance resource.
+  """
+  use Ash.Resource.Change
+
+  require Ash.Query
+
+  alias Diffo.Provider.Assigner
+
+  @impl true
+  def init(opts) do
+    case Keyword.fetch(opts, :pool) do
+      {:ok, pool} when is_atom(pool) and not is_nil(pool) ->
+        {:ok, opts}
+
+      _ ->
+        {:error, "Diffo.Provider.Changes.Assign requires a :pool atom option"}
+    end
+  end
+
+  @impl true
+  def change(changeset, opts, _context) do
+    pool = Keyword.fetch!(opts, :pool)
+
+    Ash.Changeset.after_action(changeset, fn changeset, result ->
+      with {:ok, result} <- Assigner.assign(result, changeset, pool) do
+        id = result.id
+
+        changeset.resource
+        |> Ash.Query.for_read(:read)
+        |> Ash.Query.filter(id == ^id)
+        |> Ash.read_one()
+      end
+    end)
+  end
+end

lib/diffo/provider/changes/define.ex

@@ -0,0 +1,49 @@
+# SPDX-FileCopyrightText: 2025 diffo contributors <https://github.com/diffo-dev/diffo/graphs.contributors>
+#
+# SPDX-License-Identifier: MIT
+
+defmodule Diffo.Provider.Changes.Define do
+  @moduledoc """
+  After-action change for the standard `:define` pattern.
+
+  Applies `characteristic_value_updates` to the instance's declared typed and
+  dynamic characteristics (`Characteristic.update_all/3`) and to its declared
+  pools (`Pool.update_pools/3`), then reloads the result via the resource's
+  primary `:read` action.
+
+  ## Usage
+
+      update :define do
+        argument :characteristic_value_updates, {:array, :term}
+        change Diffo.Provider.Changes.Define
+      end
+
+  This replaces the hand-written `after_action` block that threads
+  `characteristics()`, `pools()`, `Characteristic.update_all/3` and
+  `Pool.update_pools/3` together on every consumer.
+  """
+  use Ash.Resource.Change
+
+  require Ash.Query
+
+  alias Diffo.Provider.Extension.Characteristic
+  alias Diffo.Provider.Extension.Pool
+
+  @impl true
+  def change(changeset, _opts, _context) do
+    Ash.Changeset.after_action(changeset, fn changeset, result ->
+      module = changeset.resource
+
+      with {:ok, result} <- Ash.load(result, [:characteristics]),
+           {:ok, result} <- Characteristic.update_all(result, changeset, module.characteristics()),
+           {:ok, result} <- Pool.update_pools(result, changeset, module.pools()) do
+        id = result.id
+
+        module
+        |> Ash.Query.for_read(:read)
+        |> Ash.Query.filter(id == ^id)
+        |> Ash.read_one()
+      end
+    end)
+  end
+end

lib/diffo/provider/changes/relate.ex

@@ -0,0 +1,39 @@
+# SPDX-FileCopyrightText: 2025 diffo contributors <https://github.com/diffo-dev/diffo/graphs.contributors>
+#
+# SPDX-License-Identifier: MIT
+
+defmodule Diffo.Provider.Changes.Relate do
+  @moduledoc """
+  After-action change for the standard `:relate` pattern.
+
+  Creates relationships from the `:relationships` argument on the changeset via
+  `Relationship.relate_instance/2`, then reloads the result via the resource's
+  primary `:read` action.
+
+  ## Usage
+
+      update :relate do
+        argument :relationships, {:array, :struct}
+        change Diffo.Provider.Changes.Relate
+      end
+  """
+  use Ash.Resource.Change
+
+  require Ash.Query
+
+  alias Diffo.Provider.Instance.Relationship
+
+  @impl true
+  def change(changeset, _opts, _context) do
+    Ash.Changeset.after_action(changeset, fn changeset, result ->
+      with {:ok, result} <- Relationship.relate_instance(result, changeset) do
+        id = result.id
+
+        changeset.resource
+        |> Ash.Query.for_read(:read)
+        |> Ash.Query.filter(id == ^id)
+        |> Ash.read_one()
+      end
+    end)
+  end
+end

lib/diffo/provider/components/base_instance.ex

@@ -235,6 +235,7 @@ defmodule Diffo.Provider.BaseInstance do
         :features,
         Instance.derive_feature_list_name(record.type)
       )
+      |> Instance.merge_typed_and_pool_characteristics(record)
       |> Util.suppress_rename(
         :characteristics,
         Instance.derive_characteristic_list_name(record.type)
@@ -688,6 +689,8 @@ defmodule Diffo.Provider.BaseInstance do
                 :notes,
                 :features,
                 :characteristics,
+                :typed_characteristics,
+                :pool_characteristics,
                 :places,
                 :parties
               ],
@@ -699,5 +702,17 @@ defmodule Diffo.Provider.BaseInstance do
     calculate :href, :string, Diffo.Provider.Calculations.InstanceHref do
       description "the inventory href of the service or resource instance"
     end
+
+    calculate :typed_characteristics,
+              {:array, :struct},
+              Diffo.Provider.Calculations.TypedCharacteristics do
+      description "typed BaseCharacteristic records declared via the characteristics DSL"
+    end
+
+    calculate :pool_characteristics,
+              {:array, :struct},
+              Diffo.Provider.Calculations.PoolCharacteristics do
+      description "AssignableCharacteristic records declared via the pools DSL"
+    end
   end
 end

lib/diffo/provider/components/calculations/pool_characteristics.ex

@@ -0,0 +1,31 @@
+# SPDX-FileCopyrightText: 2025 diffo contributors <https://github.com/diffo-dev/diffo/graphs.contributors>
+#
+# SPDX-License-Identifier: MIT
+
+defmodule Diffo.Provider.Calculations.PoolCharacteristics do
+  @moduledoc """
+  Loads the `AssignableCharacteristic` pool records associated with an
+  instance, one per `pool :name, :thing` declaration on the resource module.
+
+  Used by `BaseInstance` to surface pool characteristics alongside the
+  dynamic `Diffo.Provider.Characteristic` records in the
+  `serviceCharacteristic` / `resourceCharacteristic` JSON view (#169).
+  """
+  use Ash.Resource.Calculation
+
+  @impl true
+  def load(_query, _opts, _context), do: []
+
+  @impl true
+  def calculate(records, _opts, _context) do
+    Enum.map(records, fn record ->
+      if function_exported?(record.__struct__, :pools, 0) and record.__struct__.pools() != [] do
+        Diffo.Provider.AssignableCharacteristic
+        |> Ash.Query.filter_input(instance_id: record.id)
+        |> Ash.read!(domain: Diffo.Provider)
+      else
+        []
+      end
+    end)
+  end
+end

lib/diffo/provider/components/calculations/typed_characteristics.ex

@@ -0,0 +1,56 @@
+# SPDX-FileCopyrightText: 2025 diffo contributors <https://github.com/diffo-dev/diffo/graphs.contributors>
+#
+# SPDX-License-Identifier: MIT
+
+defmodule Diffo.Provider.Calculations.TypedCharacteristics do
+  @moduledoc """
+  Loads all typed `BaseCharacteristic`-derived records associated with an
+  instance.
+
+  For each `characteristic :role, ValueModule` declaration on the instance's
+  resource module — including both singular and `{:array, ValueModule}` forms
+  — this calculation queries `ValueModule` by `instance_id == record.id` and
+  returns the collected records as a flat list.
+
+  Used by `BaseInstance` to surface typed characteristics alongside the
+  dynamic `Diffo.Provider.Characteristic` records in the
+  `serviceCharacteristic` / `resourceCharacteristic` JSON view (#169).
+  """
+  use Ash.Resource.Calculation
+
+  alias Diffo.Provider.Extension.Characteristic, as: CharacteristicHelper
+
+  @impl true
+  def load(_query, _opts, _context), do: []
+
+  @impl true
+  def calculate(records, _opts, _context) do
+    Enum.map(records, fn record ->
+      record
+      |> typed_value_modules()
+      |> Enum.flat_map(fn module ->
+        module
+        |> Ash.Query.filter_input(instance_id: record.id)
+        |> Ash.read!(domain: Diffo.Provider)
+      end)
+    end)
+  end
+
+  defp typed_value_modules(record) do
+    module = record.__struct__
+
+    if function_exported?(module, :characteristics, 0) do
+      module.characteristics()
+      |> Enum.map(fn %{value_type: value_type} ->
+        case value_type do
+          {:array, mod} -> mod
+          mod when is_atom(mod) -> mod
+        end
+      end)
+      |> Enum.uniq()
+      |> Enum.filter(&CharacteristicHelper.typed?/1)
+    else
+      []
+    end
+  end
+end

lib/diffo/provider/components/characteristic/extension.ex

@@ -3,6 +3,18 @@
 # SPDX-License-Identifier: MIT
 
 defmodule Diffo.Provider.Characteristic.Extension do
-  @moduledoc "Marker extension identifying a module as a valid characteristic resource."
-  use Spark.Dsl.Extension, sections: []
+  @moduledoc """
+  Marker extension identifying a module as a valid characteristic resource.
+
+  Also synthesises default `:create` and `:update` actions on
+  `BaseCharacteristic`-derived resources from the resource's declared public
+  attributes — `:create` accepts `[:name | <public_attrs>]` with
+  `:instance_id` / `:feature_id` arguments and corresponding
+  `manage_relationship` changes; `:update` accepts `<public_attrs>` only.
+  Consumers may declare their own `:create` / `:update` actions to override
+  the synthesised ones.
+  """
+  use Spark.Dsl.Extension,
+    sections: [],
+    transformers: [Diffo.Provider.Characteristic.Extension.Transformers.GenerateActions]
 end