1 files changed, 57 insertions, 5 deletions
diff --git a/scripts/regenerate-schema b/scripts/regenerate-schema
index f1018403395..75ee0c33bea 100755
--- a/scripts/regenerate-schema
+++ b/scripts/regenerate-schema
@@ -2,6 +2,7 @@
 
 # frozen_string_literal: true
 
+require 'optparse'
 require 'open3'
 require 'fileutils'
 require 'uri'
@@ -27,16 +28,37 @@ class SchemaRegenerator
   # directory when it runs.
   SCHEMA_MIGRATIONS_DIR = 'db/schema_migrations/'
 
+  def initialize(options)
+    @rollback_testing = options.delete(:rollback_testing)
+  end
+
   def execute
     Dir.chdir(File.expand_path('..', __dir__)) do
+      # Note: `db:drop` must run prior to hiding migrations.
+      #
+      # Executing a Rails DB command e.g., `reset`, `drop`, etc. triggers running the initializers.
+      # During the initialization, the default values for `application_settings` need to be set.
+      # Depending on the presence of migrations, the default values are either faked or inserted.
+      #
+      # 1. If no migration is detected, all the necessary columns are in place from `db/structure.sql`.
+      # The default values can be inserted into `application_settings` table.
+      #
+      # 2. If a migration is detected, at least one column may be missing from `db/structure.sql`
+      # and needs to be added through the detected migration. In this case, the default values are faked.
+      # If not, an error would be raised e.g., "NoMethodError: undefined method `some_setting`"
+      #
+      # See https://gitlab.com/gitlab-org/gitlab/-/merge_requests/135085#note_1628210334 for more info.
+      #
+      drop_db
       checkout_ref
       checkout_clean_schema
       hide_migrations
       remove_schema_migration_files
       stop_spring
-      reset_db
+      setup_db
       unhide_migrations
       migrate
+      rollback if @rollback_testing
     ensure
       unhide_migrations
     end
@@ -156,9 +178,15 @@ class SchemaRegenerator
   end
 
   ##
-  # Run rake task to reset the database.
-  def reset_db
-    run %q(bin/rails db:reset RAILS_ENV=test)
+  # Run rake task to drop the database.
+  def drop_db
+    run %q(bin/rails db:drop RAILS_ENV=test)
+  end
+
+  ##
+  # Run rake task to setup the database.
+  def setup_db
+    run %q(bin/rails db:setup RAILS_ENV=test)
   end
 
   ##
@@ -168,6 +196,15 @@ class SchemaRegenerator
   end
 
   ##
+  # Run rake task to rollback migrations.
+  def rollback
+    (untracked_schema_migrations + committed_schema_migrations).sort.reverse_each do |filename|
+      version = filename[/\d+\Z/]
+      run %(bin/rails db:rollback:main db:rollback:ci RAILS_ENV=test VERSION=#{version})
+    end
+  end
+
+  ##
   # Run the given +cmd+.
   #
   # The command is colored green, and the output of the command is
@@ -224,4 +261,19 @@ class SchemaRegenerator
   end
 end
 
-SchemaRegenerator.new.execute
+if $PROGRAM_NAME == __FILE__
+  options = {}
+
+  OptionParser.new do |opts|
+    opts.on("-r", "--rollback-testing", String, "Enable rollback testing") do
+      options[:rollback_testing] = true
+    end
+
+    opts.on("-h", "--help", "Prints this help") do
+      puts opts
+      exit
+    end
+  end.parse!
+
+  SchemaRegenerator.new(options).execute
+end