Avoid autolinking YouTrack issue numbers followed by letters

app/models/project_services/youtrack_service.rb

@@ -6,9 +6,9 @@ class YoutrackService < IssueTrackerService
   # {PROJECT-KEY}-{NUMBER} Examples: YT-1, PRJ-1, gl-030
   def self.reference_pattern(only_long: false)
     if only_long
-      /(?<issue>\b[A-Za-z][A-Za-z0-9_]*-\d+)/
+      /(?<issue>\b[A-Za-z][A-Za-z0-9_]*-\d+\b)/
     else
-      /(?<issue>\b[A-Za-z][A-Za-z0-9_]*-\d+)|(#{Issue.reference_prefix}(?<issue>\d+))/
+      /(?<issue>\b[A-Za-z][A-Za-z0-9_]*-\d+\b)|(#{Issue.reference_prefix}(?<issue>\d+))/
     end
   end
 

spec/models/project_services/youtrack_service_spec.rb

@@ -37,6 +37,10 @@ describe YoutrackService do
     it 'does allow project prefix on the reference' 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)
+    end
   end
 
   context 'overriding properties' do