Top Level Namespace

Modules:

AbstractController, ActionCable, ActionController, ActionDispatch, ActionMailer, ActionPack, ActionView, ActiveJob, ActiveModel, ActiveRecord, ActiveStorage, ActiveSupport, DateAndTime, Digest, Enumerable, I18n, Kernel, LoggerSilence, Mime, Minitest, Rack, Rails, SecureRandom, URI

Classes:

Array, Benchmark, BigDecimal, Class, Complex, Date, DateTime, Delegator, ERB, FalseClass, File, Float, Hash, IO, Integer, Method, Module, NilClass, Numeric, Object, Range, Rational, SourceAnnotationExtractor, String, Symbol, Time, TrueClass

Exceptions:

Exception, LoadError, NameError

Instance Chain:

self, ::ActiveRecord::Relation::RecordFetchWarning, Java