Apply suggestions from review

Co-Authored-By: NEileen M. Uchitelle <eileencodes@users.noreply.github.com>

activerecord/lib/active_record/internal_metadata.rb

@@ -7,8 +7,8 @@ module ActiveRecord
   # This class is used to create a table that keeps track of values and keys such
   # as which environment migrations were run in.
   #
-  # It is possible to enable or disable this functionality by setting the
-  # adapter configuration option `use_metadata_table` to false
+  # This is enabled by default. To disable this functionality set
+  # `use_metadata_table` to false in your database configuration.
   class InternalMetadata < ActiveRecord::Base # :nodoc:
     class << self
       def enabled?

activerecord/lib/active_record/migration.rb

@@ -190,10 +190,11 @@ def initialize(current: nil, stored: nil)
     end
   end
 
-  class EnvironmentStorageError < ActiveRecordError #:nodoc:
+  class EnvironmentStorageError < ActiveRecordError # :nodoc:
     def initialize
       msg = +"You are attempting to store the environment in a database where metadata is disabled.\n"
-      msg << "Check your database configuration to see if this is inteded."
+      msg << "Check your database configuration to see if this is intended."
+      super(msg)
     end
   end
 

activerecord/test/cases/migration_test.rb

@@ -641,13 +641,26 @@ def test_internal_metadata_stores_environment_when_other_data_exists
   end
 
   def test_internal_metadata_not_used_when_not_enabled
-    ActiveRecord::InternalMetadata.stub(:enabled?, false) do
-      migrations_path = MIGRATIONS_ROOT + "/valid"
+    ActiveRecord::InternalMetadata.drop_table
+    original_config = ActiveRecord::Base.connection.instance_variable_get("@config")
 
-      migrator = ActiveRecord::MigrationContext.new(migrations_path, @schema_migration)
-      migrator.up
-      assert_not ActiveRecord::InternalMetadata[:environment]
-    end
+    modified_config = original_config.dup.merge(use_metadata_table: false)
+
+    ActiveRecord::Base.connection
+      .instance_variable_set("@config", modified_config)
+
+    assert_not ActiveRecord::InternalMetadata.enabled?
+    assert_not ActiveRecord::InternalMetadata.table_exists?
+
+    migrations_path = MIGRATIONS_ROOT + "/valid"
+    migrator = ActiveRecord::MigrationContext.new(migrations_path, @schema_migration)
+    migrator.up
+
+    assert_not ActiveRecord::InternalMetadata[:environment]
+    assert_not ActiveRecord::InternalMetadata.table_exists?
+  ensure
+    ActiveRecord::Base.connection.instance_variable_set("@config", original_config)
+    ActiveRecord::InternalMetadata.create_table
   end
 
   def test_proper_table_name_on_migration

guides/source/configuring.md

@@ -1260,7 +1260,12 @@ Change the username and password in the `development` section as appropriate.
 
 #### Configuring Metadata Storage
 
-By default Rails will store information about your environment and schema in an internal table. If you do not want this table to be created, and are willing to give up the protections it provides (useful when working with a shared database and a database user that can not create tables).
+By default Rails will store information about your Rails environment and schema
+in an internal table named `ar_internal_metadata`.
+
+To turn this off per connection, set `use_metadata_table` in your database
+configuration. This is useful when working with a shared database and/or
+database user that cannot create tables.
 
 ```yaml
 development: