Use did_you_mean instead of jaro_winkler

CHANGELOG.md

@@ -41,6 +41,7 @@
 * [#7390](https://github.com/rubocop-hq/rubocop/issues/7390): **(Breaking)** Enabling a cop overrides disabling its department. ([@jonas054][])
 * [#7936](https://github.com/rubocop-hq/rubocop/issues/7936): Mark `Lint/BooleanSymbol` as unsafe. ([@laurmurclar][])
 * [#7948](https://github.com/rubocop-hq/rubocop/pull/7948): Mark unsafe for `Style/OptionalArguments`. ([@koic][])
+* [#7931](https://github.com/rubocop-hq/rubocop/pull/7931): Remove dependency on the `jaro_winkler` gem, instead depending on `did_you_mean`. This may be a breaking change for RuboCop libraries calling `NameSimilarity#find_similar_name`. ([@bquorning][])
 
 ## 0.82.0 (2020-04-16)
 

lib/rubocop.rb

@@ -14,7 +14,6 @@
 require_relative 'rubocop/path_util'
 require_relative 'rubocop/file_finder'
 require_relative 'rubocop/platform'
-require_relative 'rubocop/string_util'
 require_relative 'rubocop/name_similarity'
 require_relative 'rubocop/node_pattern'
 require_relative 'rubocop/string_interpreter'

lib/rubocop/cop/lint/redundant_cop_disable_directive.rb

@@ -26,7 +26,6 @@ module Lint
       #   # good
       #   x += 1
       class RedundantCopDisableDirective < Cop
-        include NameSimilarity
         include RangeHelp
 
         COP_NAME = 'Lint/RedundantCopDisableDirective'
@@ -235,7 +234,7 @@ def describe(cop)
           elsif all_cop_names.include?(cop)
             "`#{cop}`"
           else
-            similar = find_similar_name(cop, [])
+            similar = NameSimilarity.find_similar_name(cop, all_cop_names)
             if similar
               "`#{cop}` (did you mean `#{similar}`?)"
             else
@@ -244,10 +243,6 @@ def describe(cop)
           end
         end
 
-        def collect_variable_like_names(scope)
-          all_cop_names.each { |name| scope << name }
-        end
-
         def all_cop_names
           @all_cop_names ||= Cop.registry.names
         end

lib/rubocop/cop/lint/useless_assignment.rb

@@ -31,7 +31,6 @@ module Lint
       #     do_something(some_var)
       #   end
       class UselessAssignment < Cop
-        include NameSimilarity
         MSG = 'Useless assignment to variable - `%<variable>s`.'
 
         def join_force?(force_class)
@@ -94,7 +93,9 @@ def operator_assignment_message(scope, assignment)
         end
 
         def similar_name_message(variable)
-          similar_name = find_similar_name(variable.name, variable.scope)
+          variable_like_names = collect_variable_like_names(variable.scope)
+          similar_name = NameSimilarity.find_similar_name(variable.name,
+                                                          variable_like_names)
           " Did you mean `#{similar_name}`?" if similar_name
         end
 

lib/rubocop/name_similarity.rb

@@ -3,19 +3,22 @@
 module RuboCop
   # Common functionality for finding names that are similar to a given name.
   module NameSimilarity
-    MINIMUM_SIMILARITY_TO_SUGGEST = 0.9
+    module_function
 
-    def find_similar_name(target_name, scope)
-      names = collect_variable_like_names(scope)
+    def find_similar_name(target_name, names)
+      similar_names = find_similar_names(target_name, names)
+
+      similar_names.first
+    end
+
+    def find_similar_names(target_name, names)
+      names = names.dup
       names.delete(target_name)
 
-      scores = names.each_with_object({}) do |name, hash|
-        score = StringUtil.similarity(target_name, name)
-        hash[name] = score if score >= MINIMUM_SIMILARITY_TO_SUGGEST
-      end
+      spell_checker = DidYouMean::SpellChecker.new(dictionary: names)
+      similar_names = spell_checker.correct(target_name)
 
-      most_similar_name, _max_score = scores.max_by { |_, score| score }
-      most_similar_name
+      similar_names
     end
   end
 end

lib/rubocop/options.rb

@@ -248,10 +248,7 @@ def validate_cop_list(names)
       def format_message_from(name, cop_names)
         message = 'Unrecognized cop or department: %<name>s.'
         message_with_candidate = "%<message>s\nDid you mean? %<candidate>s"
-        corrections = cop_names.select do |cn|
-          score = StringUtil.similarity(cn, name)
-          score >= NameSimilarity::MINIMUM_SIMILARITY_TO_SUGGEST
-        end.sort
+        corrections = NameSimilarity.find_similar_names(name, cop_names)
 
         if corrections.empty?
           format(message, name: name)

rubocop.gemspec

@@ -33,7 +33,6 @@ Gem::Specification.new do |s|
     'bug_tracker_uri' => 'https://github.com/rubocop-hq/rubocop/issues'
   }
 
-  s.add_runtime_dependency('jaro_winkler', '~> 1.5.1')
   s.add_runtime_dependency('parallel', '~> 1.10')
   s.add_runtime_dependency('parser', '>= 2.7.0.1')
   s.add_runtime_dependency('rainbow', '>= 2.2.2', '< 4.0')

spec/fixtures/html_formatter/expected.html

@@ -658,7 +658,7 @@ <h1 class="title">RuboCop Inspection Report</h1>
             <div class="meta">
               <span class="location">Line #3</span> –
               <span class="severity warning">warning:</span>
-              <span class="message">Lint/UselessAssignment: Useless assignment to variable - <code>bar</code>.</span>
+              <span class="message">Lint/UselessAssignment: Useless assignment to variable - <code>bar</code>. Did you mean <code>baz</code>?</span>
             </div>
 
             <pre><code>    foo = <span class="highlight warning">bar</span> = baz</code></pre>