Add case-insensitive uniqueness enforcement for project identifier

app/models/projects/identifier.rb

@@ -61,28 +61,22 @@ module Projects::Identifier
                       if: -> { Setting::WorkPackageIdentifier.alphanumeric? && identifier.blank? }
 
     ### ID validators
-    # Validators for the legacy underscored identifier format (e.g. "project_one")
+    # Shared validators for all identifier formats
     validates :identifier,
               presence: true,
-              uniqueness: { case_sensitive: true },
+              uniqueness: { case_sensitive: false },
               length: { maximum: IDENTIFIER_MAX_LENGTH },
-              exclusion: RESERVED_IDENTIFIERS,
               if: ->(p) { p.persisted? || p.identifier.present? }
-    # Contains only a-z, 0-9, dashes and underscores but cannot consist of numbers only as it would clash with the id.
-    validates :identifier,
-              format: { with: /\A(?!^\d+\z)[a-z0-9\-_]+\z/ },
-              if: ->(p) {
-                p.identifier_changed? && p.identifier.present? && Setting::WorkPackageIdentifier.numeric?
-              }
 
-    # Validators for the semantic identifier format
-    validates :identifier,
-              format: { with: /\A[A-Z]/, message: :must_start_with_letter },
-              if: ->(p) { p.identifier_changed? && p.identifier.present? && Setting::WorkPackageIdentifier.alphanumeric? }
-    validates :identifier,
-              format: { with: /\A[A-Z][A-Z0-9_]*\z/, message: :no_special_characters },
-              length: { maximum: SEMANTIC_IDENTIFIER_MAX_LENGTH },
-              if: ->(p) { p.identifier_changed? && p.identifier.present? && Setting::WorkPackageIdentifier.alphanumeric? }
+    # Validators for the numeric (legacy) identifier format (e.g. "my-project", "project_one")
+    validate :identifier_numeric_format,
+             if: ->(p) { p.identifier_changed? && p.identifier.present? && Setting::WorkPackageIdentifier.numeric? }
+
+    # Validators for the semantic (alphanumeric) identifier format (e.g. "PROJ1")
+    validate :identifier_alphanumeric_format,
+             if: ->(p) { p.identifier_changed? && p.identifier.present? && Setting::WorkPackageIdentifier.alphanumeric? }
+
+    validate :identifier_not_reserved, if: -> { identifier.present? }
 
     # Complements the uniqueness validation above: once an identifier has been used by a
     # project, it remains reserved for that project even after the project moves to a new
@@ -130,14 +124,42 @@ def validation_context
 
   private
 
+  # Contains only a-z, 0-9, dashes and underscores but cannot consist of numbers only
+  # as that would clash with the numeric id.
+  def identifier_numeric_format
+    unless identifier.match?(/\A(?!^\d+\z)[a-z0-9\-_]+\z/)
+      errors.add(:identifier, :invalid)
+    end
+  end
+
+  def identifier_alphanumeric_format
+    unless identifier.match?(/\A[A-Z]/)
+      errors.add(:identifier, :must_start_with_letter)
+      return
+    end
+
+    errors.add(:identifier, :no_special_characters) unless identifier.match?(/\A[A-Z][A-Z0-9_]*\z/)
+    if identifier.length > SEMANTIC_IDENTIFIER_MAX_LENGTH
+      errors.add(:identifier, :too_long, count: SEMANTIC_IDENTIFIER_MAX_LENGTH)
+    end
+  end
+
+  def identifier_not_reserved
+    if RESERVED_IDENTIFIERS.include?(identifier&.downcase)
+      errors.add(:identifier, :exclusion)
+    end
+  end
+
   # Checks friendly_id_slugs for any project that previously used this identifier and
-  # has since changed it. It allows to switch back to an identifier the project itself
-  # has used before.
+  # has since changed it. It allows a project to switch back to an identifier it has
+  # used before. Uses LOWER() because slugs may be stored in a different case than the
+  # incoming identifier (e.g. old lowercase slug vs new uppercase alphanumeric identifier).
   def identifier_not_historically_reserved
     return if errors.any? { |error| error.attribute == :identifier && error.type == :taken }
 
     already_existing = FriendlyId::Slug
-                         .where(slug: identifier, sluggable_type: self.class.to_s)
+                         .where("LOWER(slug) = LOWER(?)", identifier)
+                         .where(sluggable_type: self.class.to_s)
                          .where.not(sluggable_id: id)
                          .exists?
 

app/services/work_packages/identifier_autofix/preview_query.rb

@@ -35,54 +35,34 @@ class PreviewQuery
       DISPLAY_COUNT = 5
 
       def call
-        total   = problematic_scope.count
-        preview = problematic_scope
-                    .select(:id, :name, :identifier)
-                    .limit(DISPLAY_COUNT)
-                    .to_a
+        analysis = ProblematicIdentifiers.new
+        total_count = analysis.count
+        projects_data = build_projects_data(analysis)
 
-        suggestions = WorkPackages::IdentifierAutofix::ProjectIdentifierSuggestionGenerator.call(
-          preview,
-          exclude: reserved_identifiers | in_use_identifiers
-        )
-
-        projects_data = suggestions.map do |entry|
-          entry.merge(error_reason: error_reason(entry[:current_identifier]))
-        end
-
-        Result.new(projects_data:, total_count: total)
+        Result.new(projects_data:, total_count:)
       end
 
       private
 
-      def problematic_scope
-        @problematic_scope ||= Project.where(
-          "length(identifier) > ? OR identifier ~ ?",
-          ProjectIdentifierSuggestionGenerator::IDENTIFIER_LENGTH[:max],
-          "[^a-zA-Z0-9_]"
-        )
-      end
-
-      def error_reason(identifier)
-        if identifier.length > ProjectIdentifierSuggestionGenerator::IDENTIFIER_LENGTH[:max]
-          :too_long
-        elsif identifier.match?(/[^a-zA-Z0-9_]/)
-          :special_characters
-        elsif in_use_identifiers.include?(identifier)
-          :in_use
-        elsif reserved_identifiers.include?(identifier)
-          :reserved
+      def build_projects_data(analysis)
+        generate_suggestions(analysis).map do |entry|
+          entry.merge(error_reason: analysis.error_reason(entry[:current_identifier]))
         end
       end
 
-      def in_use_identifiers
-        @in_use_identifiers ||= Project.where.not(id: problematic_scope.select(:id)).pluck(:identifier).to_set
+      def generate_suggestions(analysis)
+        ProjectIdentifierSuggestionGenerator.call(
+          preview_projects(analysis.scope),
+          exclude: analysis.exclusion_set.to_set(&:upcase)
+        )
       end
 
-      def reserved_identifiers
-        # TODO: OldProjectIdentifier.pluck(:identifier).to_set
-        # once the OldProjectIdentifier model and migration are added.
-        Set.new
+      def preview_projects(scope)
+        scope
+          .select(:id, :name, :identifier)
+          .order(:id)
+          .limit(DISPLAY_COUNT)
+          .to_a
       end
     end
   end

app/services/work_packages/identifier_autofix/problematic_identifiers.rb

@@ -0,0 +1,118 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+module WorkPackages
+  module IdentifierAutofix
+    # Identifies projects whose identifiers violate the semantic identifier format
+    # and provides classification and exclusion sets for suggestion generation.
+    #
+    # For main use by admin UI preview and batch migration job.
+    #
+    # == Performance notes
+    #
+    # * +#exclusion_set+ loads all non-problematic identifiers and historical slugs
+    #   into memory. Fine for a one-off admin migration; if this ever becomes a hot
+    #   path, consider a DB-backed exclusion check instead.
+    #
+    # * The regex scope conditions (+identifier ~ ?+) and +UPPER(identifier)+ won't
+    #   hit a regular index. If queries get slow on large tables, a functional index
+    #   on +UPPER(identifier)+ or a +pg_trgm+ GIN index would help.
+    #
+    #
+    class ProblematicIdentifiers
+      # Priority-ordered format rules for identifier classification.
+      FORMAT_RULES = [
+        [: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_]/) }],
+        [:not_fully_uppercased, ->(id, _) { id != id.upcase }]
+      ].freeze
+
+      def scope
+        @scope ||= exceeds_max_length
+                      .or(contains_non_alphanumeric)
+                      .or(starts_with_digit)
+                      .or(not_fully_uppercased)
+      end
+
+      delegate :count, to: :scope
+
+      # Returns a symbol classifying why the identifier is problematic.
+      # Must handle all identifiers matched by #scope.
+      def error_reason(identifier)
+        format_error_reason(identifier) || collision_error_reason(identifier) || :unknown
+      end
+
+      # Returns a Set of identifiers that must not be suggested for new assignments.
+      # Combines currently active identifiers from non-problematic projects with
+      # historically reserved identifiers from FriendlyId slug history.
+      def exclusion_set
+        reserved_identifiers | in_use_identifiers
+      end
+
+      private
+
+      def exceeds_max_length        = Project.where("length(identifier) > ?", max_identifier_length)
+      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)")
+
+      def max_identifier_length = ProjectIdentifierSuggestionGenerator::IDENTIFIER_LENGTH[:max]
+
+      def format_error_reason(identifier)
+        FORMAT_RULES.each do |reason, check|
+          return reason if check.call(identifier, max_identifier_length)
+        end
+        nil
+      end
+
+      def collision_error_reason(identifier)
+        if in_use_identifiers.include?(identifier)
+          :in_use
+        elsif reserved_identifiers.include?(identifier)
+          :reserved
+        end
+      end
+
+      def in_use_identifiers
+        @in_use_identifiers ||= Project.where.not(id: scope.select(:id)).pluck(:identifier).to_set
+      end
+
+      def reserved_identifiers
+        @reserved_identifiers ||= FriendlyId::Slug
+                                    .where(sluggable_type: Project.name)
+                                    .where("LOWER(slug) NOT IN (SELECT LOWER(identifier) FROM projects)")
+                                    .pluck(:slug)
+                                    .to_set
+      end
+    end
+  end
+end

config/locales/en.yml

@@ -410,10 +410,14 @@ en:
           label_autofixed_suggestion: Future identifier
           label_example_work_package_id: Example work package ID
         autofix_preview:
-          error_too_long: Has to be fewer than 5 characters
+          error_too_long: Has to be 10 characters or fewer
+          error_numerical: Cannot be purely numerical
+          error_starts_with_number: Cannot start with a number
           error_special_characters: Special characters not allowed
+          error_not_fully_uppercased: Must be uppercase
           error_in_use: Already in use as another project's active handle
           error_reserved: Reserved by another project's handle history
+          error_unknown: Needs manual review
           remaining_projects:
             one: "... 1 more project"
             other: "... %{count} more projects"

db/migrate/20260319120000_add_case_insensitive_uniqueness_for_project_identifiers.rb

@@ -0,0 +1,75 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+class AddCaseInsensitiveUniquenessForProjectIdentifiers < ActiveRecord::Migration[8.0]
+  disable_ddl_transaction!
+
+  def up
+    deduplicate_case_colliding_identifiers
+    remove_index :projects, :identifier, unique: true, algorithm: :concurrently, if_exists: true
+    add_index :projects, "LOWER(identifier)",
+              unique: true,
+              name: "index_projects_on_lower_identifier",
+              algorithm: :concurrently,
+              if_not_exists: true
+  end
+
+  # Note: does not undo identifier renames from deduplication. Suffixed identifiers
+  # (e.g. "FOO_2") remain valid and unique under the restored case-sensitive index.
+  def down
+    remove_index :projects, name: "index_projects_on_lower_identifier", algorithm: :concurrently, if_exists: true
+    add_index :projects, :identifier, unique: true, algorithm: :concurrently
+  end
+
+  private
+
+  # Resolves any existing case-colliding identifiers (e.g. "Foo" and "foo") so that
+  # the unique LOWER(identifier) index can be created without violation errors.
+  # The oldest project (by id) keeps its identifier; duplicates get a "_N" suffix.
+  #
+  # The NOT EXISTS guard skips rows where the suffixed identifier would itself collide.
+  # In practice this is extremely unlikely (requires both case-colliding identifiers
+  # AND a pre-existing "_N" variant). If it occurs, the subsequent index creation
+  # will fail, surfacing the issue for manual resolution.
+  def deduplicate_case_colliding_identifiers
+    execute <<~SQL.squish
+      UPDATE projects SET identifier = projects.identifier || '_' || counter.rn
+      FROM (
+        SELECT id, row_number() OVER (PARTITION BY LOWER(identifier) ORDER BY id) AS rn
+        FROM projects
+      ) AS counter
+      WHERE projects.id = counter.id AND counter.rn > 1
+        AND NOT EXISTS (
+          SELECT 1 FROM projects p2
+          WHERE LOWER(p2.identifier) = LOWER(projects.identifier || '_' || counter.rn)
+        );
+    SQL
+  end
+end

db/migrate/tables/projects.rb

@@ -49,7 +49,7 @@ def self.table(migration) # rubocop:disable Metrics/AbcSize
 
       t.index :lft, name: "index_projects_on_lft"
       t.index :rgt, name: "index_projects_on_rgt"
-      t.index :identifier, unique: true
+      t.index "LOWER(identifier)", unique: true, name: "index_projects_on_lower_identifier"
       t.index %i[lft rgt]
     end
   end

spec/features/projects/create_spec.rb

@@ -594,6 +594,7 @@
 
       fill_in "Name", with: "Flight Planning Algorithm"
       find("body").click
+      expect(page).to have_field "Identifier", with: "FPA"
 
       expect(page).to have_field "Identifier", with: "FPA"
       fill_in "Identifier", with: "3INVALID"

spec/models/project_spec.rb

@@ -606,5 +606,4 @@
       end
     end
   end
-
 end