Merge branch 'dm-search-pattern' into 'master'

Use fuzzy search with minimum length of 3 characters where appropriate

Closes #40512

See merge request gitlab-org/gitlab-ce!15592

1 files changed, 19 insertions, 6 deletions

diff --git a/lib/gitlab/sql/pattern.rb b/lib/gitlab/sql/pattern.rb
index 7c2d1d8f887..5f0c98cb5a4 100644
--- a/lib/gitlab/sql/pattern.rb
+++ b/lib/gitlab/sql/pattern.rb
@@ -4,9 +4,15 @@ module Gitlab
       extend ActiveSupport::Concern
 
       MIN_CHARS_FOR_PARTIAL_MATCHING = 3
-      REGEX_QUOTED_WORD = /(?<=^| )"[^"]+"(?= |$)/
+      REGEX_QUOTED_WORD = /(?<=\A| )"[^"]+"(?= |\z)/
 
       class_methods do
+        def fuzzy_search(query, columns)
+          matches = columns.map { |col| fuzzy_arel_match(col, query) }.compact.reduce(:or)
+
+          where(matches)
+        end
+
         def to_pattern(query)
           if partial_matching?(query)
             "%#{sanitize_sql_like(query)}%"
@@ -19,12 +25,19 @@ module Gitlab
           query.length >= MIN_CHARS_FOR_PARTIAL_MATCHING
         end
 
-        def to_fuzzy_arel(column, query)
-          words = select_fuzzy_words(query)
+        def fuzzy_arel_match(column, query)
+          query = query.squish
+          return nil unless query.present?
 
-          matches = words.map { |word| arel_table[column].matches(to_pattern(word)) }
+          words = select_fuzzy_words(query)
 
-          matches.reduce { |result, match| result.and(match) }
+          if words.any?
+            words.map { |word| arel_table[column].matches(to_pattern(word)) }.reduce(:and)
+          else
+            # No words of at least 3 chars, but we can search for an exact
+            # case insensitive match with the query as a whole
+            arel_table[column].matches(sanitize_sql_like(query))
+          end
         end
 
         def select_fuzzy_words(query)
@@ -32,7 +45,7 @@ module Gitlab
 
           query = quoted_words.reduce(query) { |q, quoted_word| q.sub(quoted_word, '') }
 
-          words = query.split(/\s+/)
+          words = query.split
 
           quoted_words.map! { |quoted_word| quoted_word[1..-2] }