Support schema dumper

Author: yahonda

activerecord/lib/active_record/connection_adapters/postgresql/column.rb

@@ -26,13 +26,11 @@ def auto_incremented_by_db?
         end
 
         def virtual?
-          # We assume every generated column is virtual, no matter the concrete type
-          # PostgreSQL 18 supports virtual generated columns that are not stored
-          @generated.present? # TODO: Consider false positives
+          @generated == "s" || @generated == "v"
         end
 
         def virtual_stored?
-          virtual? && @generated == "s"
+          @generated == "s"
         end
 
         def has_default?

activerecord/lib/active_record/connection_adapters/postgresql/schema_dumper.rb

@@ -76,7 +76,11 @@ def prepare_column_options(column)
 
             if @connection.supports_virtual_columns? && column.virtual?
               spec[:as] = extract_expression_for_virtual_column(column)
-              spec[:stored] = true # TODO: Consider virtual one and add tests for it
+              if column.virtual_stored?
+                spec[:stored] = true
+              elsif column.virtual? and !column.virtual_stored?
+                spec[:stored] = false
+              end
               spec = { type: schema_type(column).inspect }.merge!(spec)
             end
 

activerecord/test/cases/adapters/postgresql/virtual_column_test.rb

@@ -19,6 +19,8 @@ def setup
         t.virtual :name_octet_length, type: :integer, as: "OCTET_LENGTH(name)", stored: true
         t.integer :column1
         t.virtual :column2, type: :integer, as: "column1 + 1", stored: true
+        t.virtual :column3, type: :integer, as: "column1 + 2", stored: false # only if PostgreSQL >= 18.0
+        t.virtual :column4, type: :integer, as: "column1 + 3" # only if PostgreSQL >= 18.0
       end
       VirtualColumn.create(name: "Rails")
     end
@@ -102,6 +104,8 @@ def test_schema_dumping
       assert_match(/t\.virtual\s+"name_length",\s+type: :integer,\s+as: "length\(\(name\)::text\)", stored: true$/i, output)
       assert_match(/t\.virtual\s+"name_octet_length",\s+type: :integer,\s+as: "octet_length\(\(name\)::text\)", stored: true$/i, output)
       assert_match(/t\.virtual\s+"column2",\s+type: :integer,\s+as: "\(column1 \+ 1\)", stored: true$/i, output)
+      assert_match(/t\.virtual\s+"column3",\s+type: :integer,\s+as: "\(column1 \+ 2\)", stored: false$/i, output)
+      assert_match(/t\.virtual\s+"column4",\s+type: :integer,\s+as: "\(column1 \+ 3\)", stored: false$/i, output)
     end
 
     def test_build_fixture_sql