fix: inherited actions (#58)

# Issue

Closes #57.

# Overview

This PR updates Chusaku to account for controller actions that are
passed down through object-oriented class inheritance. The high-level
changes include:

- Store `#source_location` data in `Chusaku::Routes` as `source_path`.
- Map source paths to corresponding actions data and loop over that to
annotate files.
- Update tests.

lib/chusaku.rb

@@ -29,14 +29,7 @@ def call(flags = {})
         .new(Rails.root.join(controllers_pattern))
         .exclude(Rails.root.join(exclusion_pattern))
 
-      @routes.each do |controller, actions|
-        next unless controller
-
-        controller_class = "#{controller.underscore.camelize}Controller".constantize
-        action_method_name = actions.keys.first&.to_sym
-        next unless !action_method_name.nil? && controller_class.method_defined?(action_method_name)
-
-        source_path = controller_class.instance_method(action_method_name).source_location&.[](0)
+      source_paths_map.each do |source_path, actions|
         next unless controllers_paths.include?(source_path)
 
         annotate_file(path: source_path, actions: actions)
@@ -56,6 +49,34 @@ def load_tasks
 
     private
 
+    # Maps source paths to their respective routes.
+    #
+    # Example output:
+    #
+    #   {
+    #     "/path/to/users_controller.rb" => {
+    #       "edit" => [...],
+    #       "update" => [...]
+    #     }
+    #   }
+    #
+    # @return [Hash] Source paths mapped to their respective routes
+    def source_paths_map
+      map = {}
+
+      @routes.each do |controller, actions|
+        actions.each do |action, data|
+          data.each do |datum|
+            map[datum[:source_path]] ||= {}
+            map[datum[:source_path]][action] ||= []
+            map[datum[:source_path]][action].push(datum)
+          end
+        end
+      end
+
+      map
+    end
+
     # Adds annotations to the given file.
     #
     # @param path [String] Path to file
@@ -110,8 +131,9 @@ def annotate_group(group:, route_data:)
     # @param path [String] Rails path for route
     # @param name [String] Name used in route helpers
     # @param defaults [Hash] Default parameters for route
+    # @param source_path [String] Path to controller file
     # @return [String] "@route <verb> <path> {<defaults>} (<name>)"
-    def annotate_route(verb:, path:, name:, defaults:)
+    def annotate_route(verb:, path:, name:, defaults:, source_path:)
       annotation = "@route #{verb} #{path}"
       if defaults&.any?
         defaults_str =

lib/chusaku/routes.rb

@@ -9,16 +9,40 @@ class << self
       #   {
       #     "users" => {
       #       "edit" => [
-      #         {verb: "GET", path: "/users/:id", name: "edit_user"}
+      #         {
+      #           verb: "GET",
+      #           path: "/users/:id",
+      #           name: "edit_user",
+      #           defaults: {},
+      #           source_path: "/path/to/users_controller.rb"
+      #         }
       #       ],
       #       "update" => [
-      #         {verb: "PATCH", path: "/users", name: "edit_user"},
-      #         {verb: "PUT", path: "/users", name: "edit_user"}
+      #         {
+      #           verb: "PATCH",
+      #           path: "/users",
+      #           name: "edit_user",
+      #           defaults: {},
+      #           source_path: "/path/to/users_controller.rb"
+      #         },
+      #         {
+      #           verb: "PUT",
+      #           path: "/users",
+      #           name: "edit_user",
+      #           defaults: {},
+      #           source_path: "/path/to/users_controller.rb"
+      #         }
       #       ]
       #     },
       #     "empanadas" => {
       #       "create" => [
-      #         {verb: "POST", path: "/empanadas", name: nil}
+      #         {
+      #           verb: "POST",
+      #           path: "/empanadas",
+      #           name: nil,
+      #           defaults: {},
+      #           source_path: "/path/to/empanadas_controller.rb"
+      #         }
       #       ]
       #     }
       #   }
@@ -33,14 +57,20 @@ def call
 
       private
 
+      # Recursively populate the routes hash with information from the given Rails
+      # application. Accounts for Rails engines.
+      #
+      # @param app [Rails::Application] Result of `Rails.application`
+      # @param routes [Hash] Collection of all route info
+      # @return [void]
       def populate_routes(app, routes)
         app.routes.routes.each do |route|
           if route.app.engine?
             populate_routes(route.app.app, routes)
             next
           end
 
-          controller, action, defaults = extract_data_from(route)
+          controller, action, defaults, source_path = extract_data_from(route)
           routes[controller] ||= {}
           routes[controller][action] ||= []
 
@@ -49,7 +79,8 @@ def populate_routes(app, routes)
             routes: routes,
             controller: controller,
             action: action,
-            defaults: defaults
+            defaults: defaults,
+            source_path: source_path
         end
       end
 
@@ -60,11 +91,17 @@ def populate_routes(app, routes)
       # @param controller [String] Controller key
       # @param action [String] Action key
       # @param defaults [Hash] Default parameters for route
+      # @param source_path [String] Path to controller file
       # @return [void]
-      def add_info_for(route:, routes:, controller:, action:, defaults:)
+      def add_info_for(route:, routes:, controller:, action:, defaults:, source_path:)
         verbs_for(route).each do |verb|
-          routes[controller][action]
-            .push(format(route: route, verb: verb, defaults: defaults))
+          routes[controller][action].push \
+            format(
+              route: route,
+              verb: verb,
+              defaults: defaults,
+              source_path: source_path
+            )
           routes[controller][action].uniq!
         end
       end
@@ -88,13 +125,15 @@ def verbs_for(route)
       # @param route [ActionDispatch::Journey::Route] Route given by Rails
       # @param verb [String] HTTP verb
       # @param defaults [Hash] Default parameters for route
+      # @param source_path [String] Path to controller file
       # @return [Hash] { verb => String, path => String, name => String }
-      def format(route:, verb:, defaults:)
+      def format(route:, verb:, defaults:, source_path:)
         {
           verb: verb,
           path: route.path.spec.to_s.gsub("(.:format)", ""),
           name: route.name,
-          defaults: defaults
+          defaults: defaults,
+          source_path: source_path
         }
       end
 
@@ -143,16 +182,26 @@ def backfill_routes(routes)
         routes
       end
 
-      # Given a route, extract the controller and action strings.
+      # Given a route, extract the controller & action strings as well as defaults
+      # hash and source path.
       #
       # @param route [ActionDispatch::Journey::Route] Route instance
-      # @return [Array<Object>] (String, String, Hash)
+      # @return [Array<Object>] (String, String, Hash, String)
       def extract_data_from(route)
         defaults = route.defaults.dup
         controller = defaults.delete(:controller)
         action = defaults.delete(:action)
 
-        [controller, action, defaults]
+        controller_class = controller ? "#{controller.underscore.camelize}Controller".constantize : nil
+        action_method_name = action&.to_sym
+        source_path =
+          if !action_method_name.nil? && controller_class&.method_defined?(action_method_name)
+            controller_class.instance_method(action_method_name).source_location&.[](0)
+          else
+            ""
+          end
+
+        [controller, action, defaults, source_path]
       end
     end
   end

test/chusaku_test.rb

@@ -17,7 +17,7 @@
     out, _err = capture_io { exit_code = Chusaku.call(error_on_annotation: true) }
 
     assert_equal(1, exit_code)
-    assert_equal(4, File.written_files.count)
+    assert_equal(5, File.written_files.count)
     assert_includes(out, "Exited with status code 1.")
   end
 
@@ -53,13 +53,13 @@
     engine_path = "#{Rails.root}/engine/app/controllers"
 
     assert_equal(0, exit_code)
-    assert_equal(4, files.count)
+    assert_equal(5, files.count)
     refute_includes(files, "#{app_path}/api/burritos_controller.rb")
 
     expected =
       <<~HEREDOC
         module Api
-          class CakesController < ApplicationController
+          class CakesController < PastriesController
             # This route's GET action should be named the same as its PUT action,
             # even though only the PUT action is named.
             # @route GET /api/cakes/inherit (inherit)
@@ -109,6 +109,18 @@ def tacos_params
       HEREDOC
     assert_equal(expected, files["#{app_path}/api/tacos_controller.rb"])
 
+    expected =
+      <<~HEREDOC
+        class PastriesController < ApplicationController
+          # This should be annotated for each child controller that inherits from this class.
+          # @route GET /api/cakes (cakes)
+          # @route GET /api/croissants (croissants)
+          def index
+          end
+        end
+      HEREDOC
+    assert_equal(expected, files["#{app_path}/pastries_controller.rb"])
+
     expected =
       <<~HEREDOC
         class WaterliliesController < ApplicationController
@@ -165,7 +177,7 @@ def create
     out, = capture_io { exit_code = Chusaku.call(args) }
 
     assert_equal(0, exit_code)
-    assert_equal(3, File.written_files.count)
+    assert_equal(4, File.written_files.count)
     assert_equal("Chusaku has finished running.\n", out)
   end
 end

test/mock/app/controllers/api/cakes_controller.rb

@@ -1,5 +1,5 @@
 module Api
-  class CakesController < ApplicationController
+  class CakesController < PastriesController
     # This route's GET action should be named the same as its PUT action,
     # even though only the PUT action is named.
     def inherit

test/mock/app/controllers/api/croissants_controller.rb

@@ -0,0 +1,2 @@
+class Api::CroissantsController < PastriesController
+end

test/mock/app/controllers/pastries_controller.rb

@@ -0,0 +1,5 @@
+class PastriesController < ApplicationController
+  # This should be annotated for each child controller that inherits from this class.
+  def index
+  end
+end

test/mock/rails.rb

@@ -10,9 +10,11 @@
 require_relative "route_helper"
 
 require_relative "app/controllers/application_controller"
+require_relative "app/controllers/pastries_controller"
 require_relative "app/controllers/waterlilies_controller"
 require_relative "app/controllers/api/burritos_controller"
 require_relative "app/controllers/api/cakes_controller"
+require_relative "app/controllers/api/croissants_controller"
 require_relative "app/controllers/api/tacos_controller"
 
 module Rails
@@ -47,6 +49,20 @@ def application
           verb: "PUT",
           path: "/api/cakes/inherit(.:format)",
           name: "inherit"
+      routes.push \
+        mock_route \
+          controller: "api/cakes",
+          action: "index",
+          verb: "GET",
+          path: "/api/cakes(.:format)",
+          name: "cakes"
+      routes.push \
+        mock_route \
+          controller: "api/croissants",
+          action: "index",
+          verb: "GET",
+          path: "/api/croissants(.:format)",
+          name: "croissants"
       routes.push \
         mock_route \
           controller: "api/tacos",