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

SPELL_CHECKERS

Map of error types and spell checker objects.

Public Class Methods

correct_error(error_class, spell_checker) click to toggle source

Adds DidYouMean functionality to an error using a given spell checker

# File lib/did_you_mean.rb, line 92
def self.correct_error(error_class, spell_checker)
  SPELL_CHECKERS[error_class.name] = spell_checker
  error_class.prepend(Correctable) unless error_class < Correctable
end
formatter() click to toggle source

Returns the currently set formatter. By default, it is set to DidYouMean::Formatter.

# File lib/did_you_mean.rb, line 104
def self.formatter
  @formatter
end
formatter=(formatter) click to toggle source

Updates the primary formatter used to format the suggestions.

# File lib/did_you_mean.rb, line 109
def self.formatter=(formatter)
  @formatter = formatter
end