fix: decompose monolithic functions into focused helpers (CSM-023)

Break up SRP violations in Templates.do_update_template/2 and
Capabilities.for_project/2 by extracting domain-specific builder
functions and single-responsibility private helpers.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CODESMELL.md

@@ -369,11 +369,20 @@
 
 ---
 
-### CSM-023 — SRP Violations
+### ~~CSM-023 — SRP Violations~~ ✅ FIXED
-- **Files:**
+- **Fixed:** 2026-05-11
-  - `lib/bds/templates.ex:86-163` — `update_template/2` does slug changes, content changes, status transitions, file paths, transactions, cascades, and filesystem sync.
+- **What was done:**
-  - `lib/bds/scripting/capabilities.ex:22-248` — `for_project/2` returns a 200+ line map literal.
+  - **`lib/bds/templates.ex`** — `do_update_template/2`:
-- **Fix:** Decompose into smaller private pipelines or domain-specific builder functions.
+    - Extracted `resolve_next_slug/2` — determines slug from attrs or keeps current.
+    - Extracted `content_changed?/2` — checks if content attr differs from effective content.
+    - Extracted `resolve_next_status/2` — pattern-matched function heads for status transition (published + content change → draft).
+    - Extracted `build_update_attrs/5` — assembles the changeset map from resolved values.
+    - Extracted `commit_update_transaction/4` — runs the Repo transaction with cascade logic.
+    - `do_update_template/2` is now a concise pipeline: resolve → build → commit → sync.
+  - **`lib/bds/scripting/capabilities.ex`** — `for_project/2`:
+    - Extracted 13 domain-specific builder functions: `app_capabilities/2`, `project_capabilities/1`, `meta_capabilities/1`, `post_capabilities/1`, `media_capabilities/1`, `script_capabilities/1`, `template_capabilities/1`, `tag_capabilities/1`, `task_capabilities/0`, `sync_capabilities/2`, `publish_capabilities/2`, `chat_capabilities/1`, `embedding_capabilities/1`.
+    - `for_project/2` is now a 15-line dispatch map.
+  - Added 5 tests in `test/bds/csm023_srp_violations_test.exs`: source-level assertions for helper extraction in templates, delegation in do_update_template, builder function presence in capabilities, concise for_project body (≤20 lines), no inline capability definitions in for_project.
 
 ---
 

lib/bds/scripting/capabilities.ex

@@ -25,7 +25,24 @@ defmodule BDS.Scripting.Capabilities do
   @spec for_project(String.t(), keyword()) :: map()
   def for_project(project_id, opts \\ []) when is_binary(project_id) and is_list(opts) do
     %{
-      app: %{
+      app: app_capabilities(project_id, opts),
+      projects: project_capabilities(project_id),
+      meta: meta_capabilities(project_id),
+      posts: post_capabilities(project_id),
+      media: media_capabilities(project_id),
+      scripts: script_capabilities(project_id),
+      templates: template_capabilities(project_id),
+      tags: tag_capabilities(project_id),
+      tasks: task_capabilities(),
+      sync: sync_capabilities(project_id, opts),
+      publish: publish_capabilities(project_id, opts),
+      chat: chat_capabilities(opts),
+      embeddings: embedding_capabilities(project_id)
+    }
+  end
+
+  defp app_capabilities(project_id, opts) do
+    %{
       copy_to_clipboard: one_arg(fn text -> copy_to_clipboard(text, opts) end),
       get_data_paths: zero_or_one_arg(fn _args -> data_paths(project_id) end),
       get_blogmark_bookmarklet: zero_or_one_arg(fn _args -> blogmark_bookmarklet() end),
@@ -39,8 +56,11 @@ defmodule BDS.Scripting.Capabilities do
       set_preview_post_target: one_arg(fn post_id -> set_preview_post_target(post_id) end),
       show_item_in_folder: one_arg(fn item_path -> show_item_in_folder(item_path, opts) end),
       trigger_menu_action: one_arg(fn action -> trigger_menu_action(action, opts) end)
-      },
+    }
-      projects: %{
+  end
+
+  defp project_capabilities(project_id) do
+    %{
       create: zero_or_one_arg(fn attrs -> create_project(attrs) end),
       delete: one_arg(fn project_id_to_delete -> delete_project(project_id_to_delete) end),
       delete_with_data:
@@ -54,8 +74,11 @@ defmodule BDS.Scripting.Capabilities do
         two_arg(fn project_id_to_update, attrs ->
           update_project(project_id_to_update, attrs)
         end)
-      },
+    }
-      meta: %{
+  end
+
+  defp meta_capabilities(project_id) do
+    %{
       get_project_metadata: zero_or_one_arg(fn _args -> load_metadata(project_id) end),
       update_project_metadata:
         one_arg(fn attrs -> update_project_metadata(project_id, attrs) end),
@@ -73,8 +96,11 @@ defmodule BDS.Scripting.Capabilities do
       clear_publishing_preferences:
         zero_or_one_arg(fn _args -> clear_publishing_preferences(project_id) end),
       sync_on_startup: zero_or_one_arg(fn _args -> sync_meta_on_startup(project_id) end)
-      },
+    }
-      posts: %{
+  end
+
+  defp post_capabilities(project_id) do
+    %{
       create: one_arg(fn attrs -> create_post(project_id, attrs) end),
       discard: one_arg(fn post_id -> discard_post(project_id, post_id) end),
       filter: one_arg(fn filters -> filter_posts(project_id, filters) end),
@@ -120,8 +146,11 @@ defmodule BDS.Scripting.Capabilities do
       rebuild_links: zero_or_one_arg(fn _args -> rebuild_post_links(project_id) end),
       reindex_text: zero_or_one_arg(fn _args -> reindex_project_search(project_id) end),
       search: one_arg(fn query -> search_posts(project_id, query) end)
-      },
+    }
-      media: %{
+  end
+
+  defp media_capabilities(project_id) do
+    %{
       delete_translation:
         two_arg(fn media_id, language ->
           delete_media_translation(project_id, media_id, language)
@@ -161,8 +190,11 @@ defmodule BDS.Scripting.Capabilities do
         three_arg(fn media_id, language, attrs ->
           upsert_media_translation(project_id, media_id, language, attrs)
         end)
-      },
+    }
-      scripts: %{
+  end
+
+  defp script_capabilities(project_id) do
+    %{
       create: one_arg(fn attrs -> create_script(project_id, attrs) end),
       update: two_arg(fn script_id, attrs -> update_script(project_id, script_id, attrs) end),
       delete: one_arg(fn script_id -> delete_script(project_id, script_id) end),
@@ -171,8 +203,11 @@ defmodule BDS.Scripting.Capabilities do
       publish: one_arg(fn script_id -> publish_script(project_id, script_id) end),
       rebuild_from_files:
         zero_or_one_arg(fn _args -> rebuild_scripts_from_files(project_id) end)
-      },
+    }
-      templates: %{
+  end
+
+  defp template_capabilities(project_id) do
+    %{
       create: one_arg(fn attrs -> create_template(project_id, attrs) end),
       update:
         two_arg(fn template_id, attrs -> update_template(project_id, template_id, attrs) end),
@@ -184,8 +219,11 @@ defmodule BDS.Scripting.Capabilities do
       rebuild_from_files:
         zero_or_one_arg(fn _args -> rebuild_templates_from_files(project_id) end),
       validate: one_arg(fn source -> validate_template_source(source) end)
-      },
+    }
-      tags: %{
+  end
+
+  defp tag_capabilities(project_id) do
+    %{
       create: one_arg(fn attrs -> create_tag(project_id, attrs) end),
       update: two_arg(fn tag_id, attrs -> update_tag(project_id, tag_id, attrs) end),
       delete: one_arg(fn tag_id -> delete_tag(project_id, tag_id) end),
@@ -200,16 +238,22 @@ defmodule BDS.Scripting.Capabilities do
         end),
       rename: two_arg(fn tag_id, new_name -> rename_tag(project_id, tag_id, new_name) end),
       sync_from_posts: zero_or_one_arg(fn _args -> sync_tags_from_posts(project_id) end)
-      },
+    }
-      tasks: %{
+  end
+
+  defp task_capabilities do
+    %{
       get: one_arg(fn task_id -> load_task(task_id) end),
       status_snapshot: zero_or_one_arg(fn _args -> sanitize(Tasks.status_snapshot()) end),
       cancel: one_arg(fn task_id -> cancel_task(task_id) end),
       get_all: zero_or_one_arg(fn _args -> list_all_tasks() end),
       get_running: zero_or_one_arg(fn _args -> list_running_tasks() end),
       clear_completed: zero_or_one_arg(fn _args -> clear_completed_tasks() end)
-      },
+    }
-      sync: %{
+  end
+
+  defp sync_capabilities(project_id, opts) do
+    %{
       check_availability: zero_or_one_arg(fn _args -> sync_available?() end),
       get_repo_state: zero_or_one_arg(fn _args -> repo_state(project_id, opts) end),
       get_status: zero_or_one_arg(fn _args -> repo_status(project_id, opts) end),
@@ -219,11 +263,17 @@ defmodule BDS.Scripting.Capabilities do
       pull: zero_or_one_arg(fn _args -> repo_pull(project_id, opts) end),
       push: zero_or_one_arg(fn _args -> repo_push(project_id, opts) end),
       commit_all: one_arg(fn message -> repo_commit_all(project_id, message, opts) end)
-      },
+    }
-      publish: %{
+  end
+
+  defp publish_capabilities(project_id, opts) do
+    %{
       upload_site: one_arg(fn credentials -> upload_site(project_id, credentials, opts) end)
-      },
+    }
-      chat: %{
+  end
+
+  defp chat_capabilities(opts) do
+    %{
       detect_post_language:
         two_arg(fn title, content -> detect_post_language(title, content, opts) end),
       analyze_post: one_arg(fn post_id -> analyze_post(post_id, opts) end),
@@ -236,8 +286,11 @@ defmodule BDS.Scripting.Capabilities do
         end),
       translate_media_metadata:
         two_arg(fn media_id, language -> translate_media_metadata(media_id, language, opts) end)
-      },
+    }
-      embeddings: %{
+  end
+
+  defp embedding_capabilities(project_id) do
+    %{
       get_progress: zero_or_one_arg(fn _args -> embedding_progress(project_id) end),
       find_similar: two_arg(fn post_id, limit -> find_similar(post_id, limit) end),
       compute_similarities:
@@ -248,6 +301,5 @@ defmodule BDS.Scripting.Capabilities do
       dismiss_pair: two_arg(fn post_id_a, post_id_b -> dismiss_pair(post_id_a, post_id_b) end),
       index_unindexed_posts: zero_or_one_arg(fn _args -> index_unindexed_posts(project_id) end)
     }
-    }
   end
 end

lib/bds/templates.ex

@@ -95,7 +95,27 @@ defmodule BDS.Templates do
   end
 
   defp do_update_template(template, attrs) do
-    next_slug =
+    now = Persistence.now_ms()
+    next_slug = resolve_next_slug(template, attrs)
+    slug_changed? = next_slug != template.slug
+    content_changed? = content_changed?(template, attrs)
+    next_status = resolve_next_status(template, content_changed?)
+    updates = build_update_attrs(template, attrs, next_slug, next_status, now)
+
+    with {:ok, {updated_template, affected_posts}} <-
+           commit_update_transaction(template, updates, slug_changed?, now),
+         :ok <-
+           sync_template_update_side_effects(
+             template,
+             updated_template,
+             affected_posts,
+             slug_changed?
+           ) do
+      {:ok, updated_template}
+    end
+  end
+
+  defp resolve_next_slug(template, attrs) do
     if has_attr?(attrs, :slug) do
       unique_slug(
         template.project_id,
@@ -106,35 +126,30 @@ defmodule BDS.Templates do
     else
       template.slug
     end
+  end
 
-    content_changed? =
+  defp content_changed?(template, attrs) do
     has_attr?(attrs, :content) and
       attr(attrs, :content) != effective_template_content(template)
+  end
 
-    slug_changed? = next_slug != template.slug
+  defp resolve_next_status(%Template{status: :published}, true = _content_changed?), do: :draft
-    now = Persistence.now_ms()
+  defp resolve_next_status(%Template{status: status}, _content_changed?), do: status
 
-    next_status =
+  defp build_update_attrs(template, attrs, next_slug, next_status, now) do
-      if(template.status == :published and content_changed?,
-        do: :draft,
-        else: template.status
-      )
-
-    next_file_path = next_template_file_path(template, next_slug)
-
-    updates =
     %{}
     |> maybe_put(:title, attr(attrs, :title))
     |> maybe_put(:kind, attr(attrs, :kind))
     |> maybe_put(:enabled, attr(attrs, :enabled))
     |> maybe_put(:content, attr(attrs, :content))
-      |> Map.put(:file_path, next_file_path)
+    |> Map.put(:file_path, next_template_file_path(template, next_slug))
     |> Map.put(:slug, next_slug)
     |> Map.put(:version, template.version + 1)
     |> Map.put(:updated_at, now)
     |> Map.put(:status, next_status)
+  end
 
-    with {:ok, {updated_template, affected_posts}} <-
+  defp commit_update_transaction(template, updates, slug_changed?, now) do
     Repo.transaction(fn ->
       updated_template =
         template
@@ -149,16 +164,7 @@ defmodule BDS.Templates do
         end
 
       {updated_template, affected_posts}
-           end),
+    end)
-         :ok <-
-           sync_template_update_side_effects(
-             template,
-             updated_template,
-             affected_posts,
-             slug_changed?
-           ) do
-      {:ok, updated_template}
-    end
   end
 
   @spec rebuild_templates_from_files(String.t(), keyword()) :: {:ok, [Template.t()]}

test/bds/csm023_srp_violations_test.exs

@@ -0,0 +1,85 @@
+defmodule BDS.CSM023SrpViolationsTest do
+  use ExUnit.Case, async: true
+
+  describe "Templates.do_update_template/2 decomposition" do
+    test "update_template pipeline is decomposed into focused private functions" do
+      source = File.read!("lib/bds/templates.ex")
+
+      assert source =~ "defp resolve_next_slug("
+      assert source =~ "defp content_changed?("
+      assert source =~ "defp resolve_next_status("
+      assert source =~ "defp build_update_attrs("
+      assert source =~ "defp commit_update_transaction("
+
+      refute source =~ "defp do_update_template(template, attrs) do\n    next_slug =",
+             "do_update_template should delegate to focused helpers, not inline all logic"
+    end
+
+    test "do_update_template delegates to helpers instead of inlining" do
+      source = File.read!("lib/bds/templates.ex")
+
+      [do_update_body] =
+        Regex.scan(
+          ~r/defp do_update_template\(template, attrs\) do\n(.*?)(?=\n  defp )/s,
+          source,
+          capture: :all_but_first
+        )
+        |> Enum.map(&hd/1)
+
+      assert do_update_body =~ "resolve_next_slug(template, attrs)"
+      assert do_update_body =~ "content_changed?(template, attrs)"
+      assert do_update_body =~ "resolve_next_status(template, content_changed?)"
+      assert do_update_body =~ "build_update_attrs(template, attrs, next_slug, next_status, now)"
+      assert do_update_body =~ "commit_update_transaction(template, updates, slug_changed?, now)"
+    end
+  end
+
+  describe "Capabilities.for_project/2 decomposition" do
+    test "for_project delegates to domain-specific builder functions" do
+      source = File.read!("lib/bds/scripting/capabilities.ex")
+
+      assert source =~ "defp app_capabilities("
+      assert source =~ "defp project_capabilities("
+      assert source =~ "defp meta_capabilities("
+      assert source =~ "defp post_capabilities("
+      assert source =~ "defp media_capabilities("
+      assert source =~ "defp script_capabilities("
+      assert source =~ "defp template_capabilities("
+      assert source =~ "defp tag_capabilities("
+      assert source =~ "defp task_capabilities"
+      assert source =~ "defp sync_capabilities("
+      assert source =~ "defp publish_capabilities("
+      assert source =~ "defp chat_capabilities("
+      assert source =~ "defp embedding_capabilities("
+    end
+
+    test "for_project body is a concise map of builder calls" do
+      source = File.read!("lib/bds/scripting/capabilities.ex")
+      for_project_body = extract_for_project_body(source)
+
+      line_count = for_project_body |> String.split("\n") |> length()
+
+      assert line_count <= 20,
+             "for_project body should be a concise dispatch map, got #{line_count} lines"
+    end
+
+    test "no domain-specific capability entries remain in for_project body" do
+      source = File.read!("lib/bds/scripting/capabilities.ex")
+      for_project_body = extract_for_project_body(source)
+
+      refute for_project_body =~ "one_arg(",
+             "for_project body should not contain one_arg calls directly"
+
+      refute for_project_body =~ "zero_or_one_arg(",
+             "for_project body should not contain zero_or_one_arg calls directly"
+    end
+
+    defp extract_for_project_body(source) do
+      lines = String.split(source, "\n")
+      start_idx = Enum.find_index(lines, &String.contains?(&1, "def for_project("))
+      remaining = Enum.drop(lines, start_idx + 1)
+      end_idx = Enum.find_index(remaining, &(&1 == "  end"))
+      remaining |> Enum.take(end_idx) |> Enum.join("\n")
+    end
+  end
+end