checks.rb in strong_migrations-1.3.0

- old
+ new

@@ -30,11 +30,13 @@
     def check_add_column(*args)
       options = args.extract_options!
       table, column, type = args
       default = options[:default]
 
-      if !default.nil? && !adapter.add_column_default_safe?
+      # Active Record has special case for uuid columns that allows function default values
+      # https://github.com/rails/rails/blob/v7.0.3.1/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb#L92-L93
+      if !default.nil? && (!adapter.add_column_default_safe? || (volatile = (postgresql? && type.to_s == "uuid" && default.to_s.include?("()") && adapter.default_volatile?(default))))
         if options[:null] == false
           options = options.except(:null)
           append = "
 
 Then add the NOT NULL constraint in separate migrations."
@@ -42,13 +44,14 @@
 
         raise_error :add_column_default,
           add_command: command_str("add_column", [table, column, type, options.except(:default)]),
           change_command: command_str("change_column_default", [table, column, default]),
           remove_command: command_str("remove_column", [table, column]),
-          code: backfill_code(table, column, default),
+          code: backfill_code(table, column, default, volatile),
           append: append,
-          rewrite_blocks: adapter.rewrite_blocks
+          rewrite_blocks: adapter.rewrite_blocks,
+          default_type: (volatile ? "volatile" : "non-null")
       elsif default.is_a?(Proc) && postgresql?
         # adding a column with a VOLATILE default is not safe
         # https://www.postgresql.org/docs/current/sql-altertable.html#SQL-ALTERTABLE-NOTES
         # functions like random() and clock_timestamp() are VOLATILE
         # check for Proc to match Active Record
@@ -224,13 +227,21 @@
                 command_str(:add_check_constraint, [table, "#{expr_column} IS NOT NULL", {name: constraint_name, validate: false}])
               else
                 safety_assured_str(add_code)
               end
 
+            validate_constraint_code =
+              if safe_with_check_constraint
+                down_code = "#{add_constraint_code}\n    #{command_str(:change_column_null, [table, column, true])}"
+                "def up\n    #{validate_constraint_code}\n  end\n\n  def down\n    #{down_code}\n  end"
+              else
+                "def change\n    #{validate_constraint_code}\n  end"
+              end
+
             raise_error :change_column_null_postgresql,
               add_constraint_code: add_constraint_code,
-              validate_constraint_code: "def change\n    #{validate_constraint_code}\n  end"
+              validate_constraint_code: validate_constraint_code
           end
         elsif mysql? || mariadb?
           unless adapter.strict_mode?
             raise_error :change_column_null_mysql
           end
@@ -407,12 +418,17 @@
       end
 
       "#{command} #{str_args.join(", ")}"
     end
 
-    def backfill_code(table, column, default)
+    def backfill_code(table, column, default, function = false)
       model = table.to_s.classify
-      "#{model}.unscoped.in_batches do |relation| \n      relation.update_all #{column}: #{default.inspect}\n      sleep(0.01)\n    end"
+      if function
+        # update_all(column: Arel.sql(default)) also works in newer versions of Active Record
+        "#{model}.unscoped.in_batches do |relation| \n      relation.where(#{column}: nil).update_all(\"#{column} = #{default}\")\n      sleep(0.01)\n    end"
+      else
+        "#{model}.unscoped.in_batches do |relation| \n      relation.update_all #{column}: #{default.inspect}\n      sleep(0.01)\n    end"
+      end
     end
 
     def new_table?(table)
       @new_tables.include?(table.to_s)
     end