Awesome
did_you_mean
Installation
Ruby 2.3 and later ships with this gem and it will automatically be require
d when a Ruby process starts up. No special setup is required.
Examples
NameError
Correcting a Misspelled Method Name
methosd
# => NameError: undefined local variable or method `methosd' for main:Object
# Did you mean? methods
# method
Correcting a Misspelled Class Name
OBject
# => NameError: uninitialized constant OBject
# Did you mean? Object
Suggesting an Instance Variable Name
@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
Correcting a Class Variable Name
@@full_name = "Yuki Nishijima"
@@full_anme
# => NameError: uninitialized class variable @@full_anme in Object
# Did you mean? @@full_name
NoMethodError
full_name = "Yuki Nishijima"
full_name.starts_with?("Y")
# => NoMethodError: undefined method `starts_with?' for "Yuki Nishijima":String
# Did you mean? start_with?
KeyError
hash = {foo: 1, bar: 2, baz: 3}
hash.fetch(:fooo)
# => KeyError: key not found: :fooo
# Did you mean? :foo
LoadError
require 'net-http'
# => LoadError (cannot load such file -- net-http)
# Did you mean? net/http
NoMatchingPatternKeyError
hash = {foo: 1, bar: 2, baz: 3}
hash => {fooo:}
# => NoMatchingPatternKeyError: key not found: :fooo
# Did you mean? :foo
Using the DidYouMean::SpellChecker
If you need to programmatically find the closest matches to the user input, you could do so by re-using the DidYouMean::SpellChecker
object.
spell_checker = DidYouMean::SpellChecker.new(dictionary: ['email', 'fail', 'eval'])
spell_checker.correct('meail') # => ['email']
spell_checker.correct('afil') # => ['fail']
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 apply options 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)
Benchmarking
Performance is very important as the did_you_mean
gem attempts to find the closest matches on the fly right after an exception
is thrown. You could use the following rake tasks to get insights into how the gem performs:
bundle exec rake benchmark:ips:jaro
bundle exec rake benchmark:ips:levenshtein
bundle exec rake benchmark:memory
bundle exec rake benchmark:memory:jaro
bundle exec rake benchmark:memory:levenshtein
Be sure to always use bundle exec
otherwise it will activate the pre-installed version of the did_you_mean
gem rather than using what's in the lib/
.
You could also use the benchmark-driver
gem to know how each
Ruby performs differently.
bundle exec benchmark-driver benchmark/speed.yml --rbenv '2.6.0 --jit;2.6.0;2.5.3;truffleruby-1.0.0-rc10' --run-duration 30
Contributing
- Fork it (https://github.com/ruby/did_you_mean/fork)
- Create your feature branch (
git checkout -b my-new-feature
) - Commit your changes (
git commit -am 'Add some feature'
) - Make sure all tests pass (
bundle exec rake
) - Push to the branch (
git push origin my-new-feature
) - Create new Pull Request
License
Copyright (c) 2014-16 Yuki Nishijima. See MIT-LICENSE for further details.