module DidYouMean
The DidYouMean
gem adds functionality to suggest possible method/class names upon errors such as NameError
and NoMethodError
. In Ruby 2.3 or later, it is automatically activated during startup.
@example
methosd # => NameError: undefined local variable or method `methosd' for main:Object # Did you mean? methods # method OBject # => NameError: uninitialized constant OBject # Did you mean? Object @full_name = "Yuki Nishijima" first_name, last_name = full_name.split(" ") # => NameError: undefined local variable or method `full_name' for main:Object # Did you mean? @full_name @@full_name = "Yuki Nishijima" @@full_anme # => NameError: uninitialized class variable @@full_anme in Object # Did you mean? @@full_name full_name = "Yuki Nishijima" full_name.starts_with?("Y") # => NoMethodError: undefined method `starts_with?' for "Yuki Nishijima":String # Did you mean? start_with? hash = {foo: 1, bar: 2, baz: 3} hash.fetch(:fooo) # => KeyError: key not found: :fooo # Did you mean? :foo
Disabling did_you_mean
¶ ↑
Occasionally, you may want to disable the did_you_mean
gem for e.g. debugging issues in the error object itself. You can disable it entirely by specifying --disable-did_you_mean
option to the ruby
command:
$ ruby --disable-did_you_mean -e "1.zeor?" -e:1:in `<main>': undefined method `zeor?' for 1:Integer (NameError)
When you do not have direct access to the ruby
command (e.g. +rails console+, irb
), you could applyoptions using the RUBYOPT
environment variable:
$ RUBYOPT='--disable-did_you_mean' irb irb:0> 1.zeor? # => NoMethodError (undefined method `zeor?' for 1:Integer)
Getting the original error message¶ ↑
Sometimes, you do not want to disable the gem entirely, but need to get the original error message without suggestions (e.g. testing). In this case, you could use the #original_message
method on the error object:
no_method_error = begin 1.zeor? rescue NoMethodError => error error end no_method_error.message # => NoMethodError (undefined method `zeor?' for 1:Integer) # Did you mean? zero? no_method_error.original_message # => NoMethodError (undefined method `zeor?' for 1:Integer)
Constants
- PlainFormatter
The
DidYouMean::Formatter
is the basic, default formatter for the gem. The formatter responds to themessage_for
method and it returns a human readable string.- SPELL_CHECKERS
TODO: Remove on the 3.4 development start:
- VERSION
- VerboseFormatter
The
DidYouMean::Formatter
is the basic, default formatter for the gem. The formatter responds to themessage_for
method and it returns a human readable string.
Public Class Methods
Adds DidYouMean
functionality to an error using a given spell checker
# File did_you_mean.rb, line 97 def self.correct_error(error_class, spell_checker) if defined?(Ractor) new_mapping = { **@spell_checkers, error_class.to_s => spell_checker } new_mapping.default = NullChecker @spell_checkers = Ractor.make_shareable(new_mapping) else spell_checkers[error_class.to_s] = spell_checker end error_class.prepend(Correctable) if error_class.is_a?(Class) && !(error_class < Correctable) end
Returns the currently set formatter. By default, it is set to DidYouMean::Formatter
.
# File did_you_mean.rb, line 141 def self.formatter if defined?(Ractor) Ractor.current[:__did_you_mean_formatter__] || Formatter else Formatter end end
Updates the primary formatter used to format the suggestions.
# File did_you_mean.rb, line 150 def self.formatter=(formatter) if defined?(Ractor) Ractor.current[:__did_you_mean_formatter__] = formatter end end
Returns a sharable hash map of error types and spell checker objects.
# File did_you_mean.rb, line 92 def self.spell_checkers @spell_checkers end