Address review of enforced: option implementation

- change_foreign_key now raises ArgumentError when :enforced is omitted,
  matching rails/rails#57377's PG behavior. Without the guard, the bare
  call `change_foreign_key :foo, :bar` would silently emit `... DISABLE`
  via the `enforced ? 'ENABLE' : 'DISABLE'` ternary on nil.
- Docstring on change_foreign_key documents the accepted opts (:enforced
  plus identifying keys) and the side effect that bare DISABLE/ENABLE
  also flip VALIDATED — surfaced previously only in the commit message.
- visit_ForeignKeyDefinition uses o.enforced? (the predicate added on
  ForeignKeyDefinition by rails/rails#57377) for parity with !o.validate?
  on the next line.
- New specs:
  - change_foreign_key without :enforced raises ArgumentError
  - change_foreign_key identified by name: form
  - add_reference foreign_key: { enforced: false, validate: false }
  - inline t.foreign_key inside create_table
  - enforced: false + deferrable: :deferred round-trip
  - completeness assertion (key?(:validate) == false) on the "enables a
    DISABLEd FK" spec, confirming ENABLE VALIDATE state after bare ENABLE
- Trim duplicative spec comments per the project's terse-comments norm.

To be squashed into 748a42a once CI is green.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: yahonda

lib/active_record/connection_adapters/oracle_enhanced/schema_creation.rb

@@ -101,11 +101,10 @@ def add_column_options!(sql, options)
           def visit_ForeignKeyDefinition(o)
             super.dup.tap do |sql|
               sql << " DEFERRABLE INITIALLY #{o.deferrable.to_s.upcase}" if o.deferrable
-              enforced = o.options.fetch(:enforced, true)
-              sql << " DISABLE" unless enforced
+              sql << " DISABLE" unless o.enforced?
               if !o.validate?
                 sql << " NOVALIDATE"
-              elsif !enforced
+              elsif !o.enforced?
                 sql << " VALIDATE"
               end
             end

lib/active_record/connection_adapters/oracle_enhanced/schema_statements.rb

@@ -823,7 +823,15 @@ def validate_foreign_key(from_table, to_table = nil, **options) # :nodoc:
           validate_constraint(from_table, fk_name_to_validate)
         end
 
+        # Accepted options: +:enforced+ (the only mutable axis) plus the identifying
+        # keys +:column+, +:name+, +:to_table+ passed through to +foreign_key_for!+.
+        # ALTER ... MODIFY CONSTRAINT name DISABLE/ENABLE follows Oracle's defaults:
+        # bare DISABLE leaves the constraint at DISABLE NOVALIDATE, and bare ENABLE
+        # at ENABLE VALIDATE; introspection reflects those side effects on +:validate+.
         def change_foreign_key(from_table, to_table = nil, **options) # :nodoc:
+          unless options.key?(:enforced)
+            raise ArgumentError, "change_foreign_key requires at least one option (e.g. enforced:)"
+          end
           enforced = options[:enforced]
           fk_name = foreign_key_for!(from_table, to_table: to_table, **options.except(:enforced)).name
           execute "ALTER TABLE #{quote_table_name(from_table)} MODIFY CONSTRAINT #{quote_column_name(fk_name)} #{enforced ? 'ENABLE' : 'DISABLE'}"

spec/active_record/connection_adapters/oracle_enhanced/schema_dumper_spec.rb

@@ -402,7 +402,6 @@ def drop_test_posts_table
       end
 
       dumped = dump_table_schema "test_comments"
-      # validate: true is the Rails default and is not emitted; only enforced: false appears.
       expect(dumped).to match(/add_foreign_key "test_comments", "test_posts".*enforced: false/)
       expect(dumped).not_to match(/validate: /)
 

spec/active_record/connection_adapters/oracle_enhanced/schema_statements_spec.rb

@@ -1951,19 +1951,13 @@ class ::TestComment < ActiveRecord::Base
       expect(fk.options.key?(:validate)).to be(false)
     end
 
-    # `enforced:` and `validate:` are independent options mapping to Oracle's
-    # 4-state constraint model. See the matrix in
-    # OracleEnhanced::SchemaCreation#visit_ForeignKeyDefinition.
-
     it "creates DISABLE VALIDATE when enforced: false is given (validate defaults to true)" do
       schema_define do
         add_foreign_key :test_comments, :test_posts, enforced: false
       end
       fk = ActiveRecord::Base.lease_connection.foreign_keys(:test_comments).first
       expect(fk.options[:enforced]).to be(false)
       expect(fk.options.key?(:validate)).to be(false)
-      # DISABLE VALIDATE blocks DML on the table (ORA-25128). Users who want
-      # PostgreSQL-NOT-ENFORCED semantics must pass `validate: false` as well.
       expect do
         TestComment.create(body: "test", test_post_id: 1)
       end.to raise_error(/ORA-25128/)
@@ -1997,6 +1991,7 @@ class ::TestComment < ActiveRecord::Base
       end
       fk = ActiveRecord::Base.lease_connection.foreign_keys(:test_comments).first
       expect(fk.options.key?(:enforced)).to be(false)
+      expect(fk.options.key?(:validate)).to be(false)
       expect do
         TestComment.create(body: "test", test_post_id: 1)
       end.to raise_error(/ORA-02291/)
@@ -2009,13 +2004,66 @@ class ::TestComment < ActiveRecord::Base
       end
       fk = ActiveRecord::Base.lease_connection.foreign_keys(:test_comments).first
       expect(fk.options[:enforced]).to be(false)
-      # ALTER ... MODIFY CONSTRAINT name DISABLE drops the VALIDATED state too,
-      # so introspection reports validate: false alongside enforced: false.
       expect(fk.options[:validate]).to be(false)
       expect do
         TestComment.create(body: "test", test_post_id: 1)
       end.not_to raise_error
     end
+
+    it "raises ArgumentError when change_foreign_key is called without :enforced" do
+      schema_define do
+        add_foreign_key :test_comments, :test_posts
+      end
+      expect do
+        ActiveRecord::Base.lease_connection.change_foreign_key :test_comments, :test_posts
+      end.to raise_error(ArgumentError, /change_foreign_key requires at least one option/)
+    end
+
+    it "toggles enforced via change_foreign_key identified by name:" do
+      schema_define do
+        add_foreign_key :test_comments, :test_posts, name: "comments_posts_fk"
+        change_foreign_key :test_comments, name: "comments_posts_fk", enforced: false
+      end
+      fk = ActiveRecord::Base.lease_connection.foreign_keys(:test_comments).first
+      expect(fk.options[:enforced]).to be(false)
+    end
+
+    it "honors enforced: false on add_reference foreign_key option hash" do
+      schema_define do
+        drop_table :test_comments, if_exists: true
+        create_table :test_comments, force: true do |t|
+          t.string :body, limit: 4000
+        end
+        add_reference :test_comments, :test_post, foreign_key: { enforced: false, validate: false }
+      end
+      fk = ActiveRecord::Base.lease_connection.foreign_keys(:test_comments).first
+      expect(fk.options[:enforced]).to be(false)
+      expect(fk.options[:validate]).to be(false)
+    end
+
+    it "honors enforced: false on inline t.foreign_key inside create_table" do
+      schema_define do
+        drop_table :test_comments, if_exists: true
+        create_table :test_comments, force: true do |t|
+          t.string :body, limit: 4000
+          t.references :test_post
+          t.foreign_key :test_posts, enforced: false, validate: false
+        end
+      end
+      fk = ActiveRecord::Base.lease_connection.foreign_keys(:test_comments).first
+      expect(fk.options[:enforced]).to be(false)
+      expect(fk.options[:validate]).to be(false)
+    end
+
+    it "round-trips enforced: false combined with deferrable: :deferred" do
+      schema_define do
+        add_foreign_key :test_comments, :test_posts, enforced: false, validate: false, deferrable: :deferred
+      end
+      fk = ActiveRecord::Base.lease_connection.foreign_keys(:test_comments).first
+      expect(fk.options[:enforced]).to be(false)
+      expect(fk.options[:validate]).to be(false)
+      expect(fk.options[:deferrable]).to eq(:deferred)
+    end
   end
 
   describe "check constraints" do