V3SlotSetters linter/codemod draft

lib/view_component/codemods/v3_slot_setters.rb

@@ -0,0 +1,183 @@
+# Usage (in rails console):
+#
+# Make sure all your ViewComponents are loaded before running the codemod.
+#
+#     Zeitwerk::Loader.eager_load_all
+#
+# Run the codemod:
+#
+#     ViewComponent::Codemods::V3SlotSetters.new.call
+#
+# If your app uses custom paths for views, you can pass them in:
+#
+#     ViewComponent::Codemods::V3SlotSetters.new(
+#       view_path: "../app/views",
+#     ).call
+
+module ViewComponent
+  module Codemods
+    class V3SlotSetters
+      TEMPLATE_LANGUAGES = %w[erb slim haml].join(",").freeze
+      RENDER_REGEX = /render[( ](?<component>\w+(?:::\w+)*)\.new[) ]+(do|\{) \|(?<arg>\w+)\b/
+
+      Suggestion = Struct.new(:file, :line, :message)
+
+      def initialize(view_component_path: [], view_path: [])
+        @view_component_path = view_component_path
+        @view_path = view_path
+      end
+
+      def call
+        puts "Using ViewComponent path: #{view_component_paths.join(", ")}"
+        puts "Using Views path: #{view_paths.join(", ")}"
+        puts "#{view_components.size} ViewComponents found"
+        puts "#{slottable_components.size} ViewComponents using slots found"
+        puts "#{view_component_files.size} view component files found"
+        puts "#{view_files.size} view files found"
+        process_all_files
+      end
+
+      def process_all_files
+        all_files.each do |file|
+          process_file(file)
+        end
+      end
+
+      def process_file(file)
+        @suggestions = []
+
+        @suggestions += scan_exact_matches(file)
+        @suggestions += scan_uncertain_matches(file)
+
+        if @suggestions.any?
+          puts
+          puts "File: #{file}"
+          @suggestions.each do |s|
+            puts "=> line #{s.line}: #{s.message}"
+          end
+        end
+      end
+
+      private
+
+      def scan_exact_matches(file)
+        [].tap do |suggestions|
+          rendered_components = []
+          content = File.read(file)
+
+          if render_match = content.match(RENDER_REGEX)
+            component = render_match[:component]
+            arg = render_match[:arg]
+
+            if registered_slots.key?(component.constantize)
+              used_slots_names = registered_slots[component.constantize]
+              rendered_components << { component: component, arg: arg, slots: used_slots_names }
+            end
+          end
+
+          File.open(file) do |f|
+            f.each_line do |line|
+              rendered_components.each do |rendered_component|
+                arg = rendered_component[:arg]
+                slots = rendered_component[:slots]
+
+                if matches = line.scan(/#{arg}\.#{Regexp.union(slots)}/)
+                  matches.each do |match|
+                    suggestions << Suggestion.new(file, f.lineno, "probably replace `#{match}` with `#{match.gsub("#{arg}.", "#{arg}.with_")}`")
+                  end
+                end
+              end
+            end
+          end
+        end
+      end
+
+      def scan_uncertain_matches(file)
+        [].tap do |suggestions|
+          File.open(file) do |f|
+            f.each_line do |line|
+              if matches = line.scan(/(?<!\s)\.(?<slot>#{Regexp.union(all_registered_slot_names)})/)
+                next if matches.size == 0
+
+                matches.flatten.each do |match|
+                  next if @suggestions.find { |s| s.file == file && s.line == f.lineno }
+
+                  suggestions << Suggestion.new(file, f.lineno, "maybe replace `.#{match}` with `.with_#{match}`")
+                end
+              end
+            end
+          end
+        end
+      end
+
+      def view_components
+        ViewComponent::Base.descendants
+      end
+
+      def slottable_components
+        view_components.select do |comp|
+          comp.registered_slots.any?
+        end
+      end
+
+      def registered_slots
+        @registered_slots ||= {}.tap do |slots|
+          puts
+          puts "Detected slots:"
+          slottable_components.each do |comp|
+            puts "- `#{comp}` has slots: #{comp.registered_slots.keys.join(', ')}"
+            slots[comp] = comp.registered_slots.map do |slot_name, slot|
+              normalized_slot_name(slot_name, slot)
+            end
+          end
+        end
+      end
+
+      def all_registered_slot_names
+        @all_registered_slot_names ||= registered_slots.values.flatten.uniq
+      end
+
+      def view_component_files
+        Dir.glob(Rails.root.join(view_component_path_glob, "**", "*.{rb,#{TEMPLATE_LANGUAGES}}"))
+      end
+
+      def view_files
+        Dir.glob(Rails.root.join(view_path_glob, "**", "*.{#{TEMPLATE_LANGUAGES}}"))
+      end
+
+      def all_files
+        view_component_files + view_files
+      end
+
+      def view_component_paths
+        @view_component_paths ||= [
+          Rails.application.config.view_component.view_component_path,
+          @view_component_path,
+        ].flatten.compact.uniq
+      end
+
+      def view_component_path_glob
+        return view_component_paths.first if view_component_paths.size == 1
+
+        "{#{view_component_paths.join(',')}}"
+      end
+
+      def view_paths
+        @view_paths ||= [
+          "app/views",
+          @view_path,
+        ].flatten.compact.uniq
+      end
+
+      def view_path_glob
+        return view_paths.first if view_paths.size == 1
+
+        "{#{view_paths.join(',')}}"
+      end
+
+      def normalized_slot_name(slot_name, slot)
+        slot[:collection] ? ActiveSupport::Inflector.singularize(slot_name) : slot_name.to_s
+      end
+    end
+  end
+end