Added ignored_databases option

CHANGELOG.md

@@ -1,5 +1,7 @@
 ## 1.7.1 (unreleased)
 
+- Added `ignored_databases` option
+- Added warning for unsupported adapter
 - Updated instructions for removing a column to append to `ignored_columns`
 
 ## 1.7.0 (2024-01-05)

README.md

@@ -797,6 +797,14 @@ By default, checks are disabled when migrating down. Enable them with:
 StrongMigrations.check_down = true
 ```
 
+## Multiple Databases
+
+Disable all functionality for specific databases with: [unreleased]
+
+```ruby
+StrongMigrations.ignored_databases += [:catalog]
+```
+
 ## Custom Messages
 
 To customize specific messages, create an initializer with:

lib/strong_migrations.rb

@@ -29,7 +29,7 @@ class << self
       :target_postgresql_version, :target_mysql_version, :target_mariadb_version,
       :enabled_checks, :lock_timeout, :statement_timeout, :check_down, :target_version,
       :safe_by_default, :target_sql_mode, :lock_timeout_retries, :lock_timeout_retry_delay,
-      :alphabetize_schema
+      :alphabetize_schema, :ignored_databases
     attr_writer :lock_timeout_limit
   end
   self.auto_analyze = false
@@ -40,6 +40,7 @@ class << self
   self.safe_by_default = false
   self.check_down = false
   self.alphabetize_schema = false
+  self.ignored_databases = []
 
   # private
   def self.developer_env?

lib/strong_migrations/checker.rb

@@ -28,6 +28,8 @@ def self.safety_assured
     end
 
     def perform(method, *args)
+      return if !enabled?
+      check_adapter
       check_version_supported
       set_timeouts
       check_lock_timeout
@@ -131,6 +133,28 @@ def version_safe?
 
     private
 
+    def enabled?
+      return true if StrongMigrations.ignored_databases.empty?
+
+      # Active Record 6.0 supports multiple databases
+      # but connection.pool.spec.name always returns "primary"
+      # in migrations with rails db:migrate
+      if ActiveRecord::VERSION::STRING.to_f < 6.1
+        # error class is not shown in db:migrate output so ensure message is descriptive
+        raise StrongMigrations::Error, "StrongMigrations.ignored_databases is not supported for Active Record < 6.1"
+      end
+
+      !StrongMigrations.ignored_databases.map(&:to_s).include?(connection.pool.db_config.name)
+    end
+
+    def check_adapter
+      if adapter.instance_of?(Adapters::AbstractAdapter)
+        # TODO raise error in 2.0
+        # TODO add database name for Active Record 6.1+
+        warn "[strong_migrations] Unsupported adapter: #{connection.adapter_name}. Use StrongMigrations.ignored_databases to silence this warning."
+      end
+    end
+
     def check_version_supported
       return if defined?(@version_checked)
 

lib/strong_migrations/migrator.rb

@@ -6,8 +6,10 @@ def ddl_transaction(migration, *args)
       # handle MigrationProxy class
       migration = migration.send(:migration) if migration.respond_to?(:migration, true)
 
-      # retry migration since the entire transaction needs to be rerun
       checker = migration.send(:strong_migrations_checker)
+      return super unless checker.send(:enabled?)
+
+      # retry migration since the entire transaction needs to be rerun
       checker.retry_lock_timeouts(check_committed: true) do
         # failed transaction reverts timeout, so need to re-apply
         checker.timeouts_set = false

test/multiple_databases_test.rb

@@ -40,6 +40,30 @@ def test_target_version_unsupported
     end
   end
 
+  def test_ignored_databases
+    skip unless multiple_dbs?
+
+    with_ignored_databases([:animals]) do
+      with_database(:primary) do
+        assert_unsafe ExecuteArbitrarySQL
+      end
+      with_database(:animals) do
+        assert_safe ExecuteArbitrarySQL
+      end
+    end
+  end
+
+  def test_ignored_databases_unsupported
+    skip if multiple_dbs?
+
+    with_ignored_databases([:animals]) do
+      error = assert_raises(StrongMigrations::Error) do
+        assert_safe ExecuteArbitrarySQL
+      end
+      assert_equal "StrongMigrations.ignored_databases is not supported for Active Record < 6.1", error.message
+    end
+  end
+
   private
 
   def with_database(database, &block)
@@ -59,6 +83,13 @@ def with_database(database, &block)
     ActiveRecord::Base.establish_connection(previous_db_config) if previous_db_config
   end
 
+  def with_ignored_databases(databases)
+    StrongMigrations.ignored_databases = databases
+    yield
+  ensure
+    StrongMigrations.ignored_databases = []
+  end
+
   def multiple_dbs?
     ActiveRecord::VERSION::STRING.to_f >= 6.1
   end