Allow underscores in PreviewQuery identifier classification

The production spec explicitly allows underscores in alphanumeric
identifiers. PreviewQuery's :special_characters rule and SQL scope
incorrectly flagged them. Updated regex from [^a-zA-Z0-9] to
[^a-zA-Z0-9_] in both the FORMAT_RULES lambda and the
contains_non_alphanumeric scope.

Also added a comment to set_raw_identifier explaining why Arel.sql
is necessary (update_all applies normalizes in this Rails version).

Author: akabiru

app/services/work_packages/identifier_autofix/preview_query.rb

@@ -39,7 +39,7 @@ class PreviewQuery
         [:too_long, ->(id, max) { id.length > max }],
         [:numerical, ->(id, _) { id.match?(/\A\d+\z/) }],
         [:starts_with_number, ->(id, _) { id.match?(/\A\d/) }],
-        [:special_characters, ->(id, _) { id.match?(/[^a-zA-Z0-9]/) }],
+        [:special_characters, ->(id, _) { id.match?(/[^a-zA-Z0-9_]/) }],
         [:not_uppercase, ->(id, _) { id != id.upcase }]
       ].freeze
 
@@ -78,7 +78,7 @@ def problematic_scope
       end
 
       def exceeds_max_length        = Project.where("length(identifier) > ?", max_identifier_length)
-      def contains_non_alphanumeric = Project.where("identifier ~ ?", "[^a-zA-Z0-9]")
+      def contains_non_alphanumeric = Project.where("identifier ~ ?", "[^a-zA-Z0-9_]")
       def starts_with_digit         = Project.where("identifier ~ ?", "^[0-9]")
       def not_fully_uppercased      = Project.where("identifier != UPPER(identifier)")
 

spec/services/work_packages/identifier_autofix/preview_query_spec.rb

@@ -36,6 +36,9 @@
   let(:display_count) { described_class::DISPLAY_COUNT }
 
   # Store identifiers bypassing normalizes (which would downcase/upcase them)
+  # Arel.sql is intentional: update_all(identifier:) applies `normalizes`,
+  # which would upcase/downcase the value — defeating the purpose of setting
+  # a raw identifier to simulate pre-existing data.
   def set_raw_identifier(project, identifier)
     Project.where(id: project.id).update_all(Arel.sql("identifier = #{Project.connection.quote(identifier)}"))
     project
@@ -58,12 +61,12 @@ def create_valid_project(name:, identifier:)
     end
   end
 
-  context "when a project has underscores in its identifier" do
+  context "when a project has underscores and lowercase in its identifier" do
     before { create_valid_project(name: "My Project", identifier: "my_proj") }
 
-    it "flags it as problematic (underscores are not valid in semantic identifiers)" do
+    it "flags it as :not_uppercase (underscores are allowed per spec)" do
       expect(result.total_count).to eq(1)
-      expect(result.projects_data.first[:error_reason]).to eq(:special_characters)
+      expect(result.projects_data.first[:error_reason]).to eq(:not_uppercase)
     end
   end