Detailed output when running only one spec file

spec/base_spec_helper.rb

@@ -129,6 +129,16 @@ RSpec.configure do |config|
   # https://rspec.info/features/3-12/rspec-core/configuration/zero-monkey-patching-mode/
   config.disable_monkey_patching!
 
+  # Many RSpec users commonly either run the entire suite or an individual
+  # file, and it's useful to allow more verbose output when running an
+  # individual spec file.
+  if config.files_to_run.one?
+    # Use the documentation formatter for detailed output,
+    # unless a formatter has already been configured
+    # (e.g. via a command-line flag).
+    config.default_formatter = "doc"
+  end
+
   # Reset locale for all specs.
   config.around(:each) do |example|
     I18n.with_locale(:en) { example.run }