Adds a Rails::Command for Notes

* It is called with `rails notes`
* It defaults to displaying [OPTIMIZE, FIXME and TODO] annotations
* It accepts custom annotations by using `rails notes -a CUSTOM_ANNOTATION OTHER_ANNOTATION`
* It defaults to look for annotations in [app config db lib test] as dictated by SourceAnnotationExtractor
* It supports ENV["SOURCE_ANNOTATION_DIRECTORIES"] but adds a deprecation warning and recommends using register_directories instead

2 files changed, 121 insertions, 0 deletions

diff --git a/railties/lib/rails/commands/notes/notes_command.rb b/railties/lib/rails/commands/notes/notes_command.rb
new file mode 100644
index 0000000000..8895cb0707
--- /dev/null
+++ b/railties/lib/rails/commands/notes/notes_command.rb
@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+require "rails/source_annotation_extractor"
+
+module Rails
+  module Command
+    class NotesCommand < Base # :nodoc:
+      class_option :annotations, aliases: "-a", desc: "Filter by specific annotations, e.g. Foobar TODO", type: :array, default: %w(OPTIMIZE FIXME TODO)
+
+      def perform(*)
+        deprecation_warning
+        display_annotations
+      end
+
+      private
+        def display_annotations
+          annotations = options[:annotations]
+          tag = (annotations.length > 1)
+
+          Rails::SourceAnnotationExtractor.enumerate annotations.join("|"), tag: tag, dirs: directories
+        end
+
+        def directories
+          Rails::SourceAnnotationExtractor::Annotation.directories + source_annotation_directories
+        end
+
+        def deprecation_warning
+          return if source_annotation_directories.empty?
+          ActiveSupport::Deprecation.warn("`SOURCE_ANNOTATION_DIRECTORIES` will be deprecated in Rails 6.1. You can add default directories by using config.annotations.register_directories instead.")
+        end
+
+        def source_annotation_directories
+          ENV["SOURCE_ANNOTATION_DIRECTORIES"].to_s.split(",")
+        end
+    end
+  end
+end
diff --git a/railties/test/commands/notes_test.rb b/railties/test/commands/notes_test.rb
new file mode 100644
index 0000000000..927c55251e
--- /dev/null
+++ b/railties/test/commands/notes_test.rb
@@ -0,0 +1,84 @@
+# frozen_string_literal: true
+
+require "isolation/abstract_unit"
+require "rails/command"
+require "rails/commands/notes/notes_command"
+
+class Rails::Command::NotesTest < ActiveSupport::TestCase
+  setup :build_app
+  teardown :teardown_app
+
+  test "`rails notes` displays results for default directories and default annotations" do
+    app_file "app/controllers/some_controller.rb", "# OPTIMIZE: note in app directory"
+    app_file "config/initializers/some_initializer.rb", "# TODO: note in config directory"
+    app_file "db/some_seeds.rb", "# FIXME: note in db directory"
+    app_file "lib/some_file.rb", "# TODO: note in lib directory"
+    app_file "test/some_test.rb", 1000.times.map { "" }.join("\n") << "# FIXME: note in test directory"
+
+    app_file "some_other_dir/blah.rb", "# TODO: note in some_other directory"
+
+    assert_equal <<~OUTPUT, run_notes_command
+      app/controllers/some_controller.rb:
+        * [   1] [OPTIMIZE] note in app directory
+
+      config/initializers/some_initializer.rb:
+        * [   1] [TODO] note in config directory
+
+      db/some_seeds.rb:
+        * [   1] [FIXME] note in db directory
+
+      lib/some_file.rb:
+        * [   1] [TODO] note in lib directory
+
+      test/some_test.rb:
+        * [1000] [FIXME] note in test directory
+
+    OUTPUT
+  end
+
+  test "`rails notes` displays an empty array when no results were found" do
+    assert_equal "", run_notes_command
+  end
+
+  test "`rails notes --annotations` displays results for a single annotation without being prefixed by a tag" do
+    app_file "db/some_seeds.rb", "# FIXME: note in db directory"
+    app_file "test/some_test.rb", 1000.times.map { "" }.join("\n") << "# FIXME: note in test directory"
+
+    app_file "app/controllers/some_controller.rb", "# OPTIMIZE: note in app directory"
+    app_file "config/initializers/some_initializer.rb", "# TODO: note in config directory"
+
+    assert_equal <<~OUTPUT, run_notes_command(["--annotations", "FIXME"])
+      db/some_seeds.rb:
+        * [   1] note in db directory
+
+      test/some_test.rb:
+        * [1000] note in test directory
+
+    OUTPUT
+  end
+
+  test "`rails notes --annotations` displays results for multiple annotations being prefixed by a tag" do
+    app_file "app/controllers/some_controller.rb", "# FOOBAR: note in app directory"
+    app_file "config/initializers/some_initializer.rb", "# TODO: note in config directory"
+    app_file "lib/some_file.rb", "# TODO: note in lib directory"
+
+    app_file "test/some_test.rb", 1000.times.map { "" }.join("\n") << "# FIXME: note in test directory"
+
+    assert_equal <<~OUTPUT, run_notes_command(["--annotations", "FOOBAR", "TODO"])
+      app/controllers/some_controller.rb:
+        * [1] [FOOBAR] note in app directory
+
+      config/initializers/some_initializer.rb:
+        * [1] [TODO] note in config directory
+
+      lib/some_file.rb:
+        * [1] [TODO] note in lib directory
+
+    OUTPUT
+  end
+
+  private
+    def run_notes_command(args = [])
+      rails "notes", args
+    end
+end