Improve reference pattern with word boundary

This is a follow-up from 08908856 to improve the reference pattern.
Match: EXT-123
Not match: EXT-123A

app/models/project_services/issue_tracker_service.rb

@@ -19,9 +19,9 @@ class IssueTrackerService < Service
   # overridden patterns. See ReferenceRegexes.external_pattern
   def self.reference_pattern(only_long: false)
     if only_long
-      /(\b[A-Z][A-Z0-9_]*-)(?<issue>\d+)/
+      /(\b[A-Z][A-Z0-9_]*-)(?<issue>\d+\b)/
     else
-      /(\b[A-Z][A-Z0-9_]*-|#{Issue.reference_prefix})(?<issue>\d+)/
+      /(\b[A-Z][A-Z0-9_]*-|#{Issue.reference_prefix})(?<issue>\d+\b)/
     end
   end
 

app/models/project_services/youtrack_service.rb

@@ -8,7 +8,7 @@ class YoutrackService < IssueTrackerService
     if only_long
       /(?<issue>\b[A-Za-z][A-Za-z0-9_]*-\d+\b)/
     else
-      /(?<issue>\b[A-Za-z][A-Za-z0-9_]*-\d+\b)|(#{Issue.reference_prefix}(?<issue>\d+))/
+      /(?<issue>\b[A-Za-z][A-Za-z0-9_]*-\d+\b)|(#{Issue.reference_prefix}(?<issue>\d+\b))/
     end
   end
 

lib/gitlab/regex.rb

@@ -112,7 +112,7 @@ module Gitlab
     # Based on Jira's project key format
     # https://confluence.atlassian.com/adminjiraserver073/changing-the-project-key-format-861253229.html
     def jira_issue_key_regex
-      @jira_issue_key_regex ||= /[A-Z][A-Z_0-9]+-\d+/
+      @jira_issue_key_regex ||= /[A-Z][A-Z_0-9]+-\d+\b/
     end
 
     def jira_transition_id_regex

spec/models/project_services/youtrack_service_spec.rb

@@ -38,8 +38,8 @@ describe YoutrackService do
       expect(described_class.reference_pattern.match('YT-123')[:issue]).to eq('YT-123')
     end
 
-    it 'does not allow issue number to be followed by a letter' do
-      expect(described_class.reference_pattern.match('YT-123A')).to eq(nil)
+    it 'allows lowercase project key on the reference' do
+      expect(described_class.reference_pattern.match('yt-123')[:issue]).to eq('yt-123')
     end
   end
 

spec/support/shared_examples/models/issue_tracker_service_shared_examples.rb

@@ -21,4 +21,8 @@ RSpec.shared_examples 'allows project key on reference pattern' do |url_attr|
     expect(described_class.reference_pattern.match('3EXT_EXT-1234')).to eq nil
     expect(described_class.reference_pattern.match('EXT_EXT-1234')[0]).to eq 'EXT_EXT-1234'
   end
+
+  it 'does not allow issue number to finish with a letter' do
+    expect(described_class.reference_pattern.match('EXT-123A')).to eq(nil)
+  end
 end