discourse/spec/components/migration/safe_migrate_spec.rb
Guo Xiang Tan 40fa96777d
FEATURE: Post deployment migrations. (#6406)
This moves us away from the delayed drops pattern which
was problematic on two counts. First, it uses a hardcoded "delay for"
duration which may be too short for certain deployment strategies.
Second, delayed drop doesn't ensure that it only runs after
the latest application code has been deployed. If the migration runs
and the application code fails to deploy, running the migration after
"delay for" has been met will cause the application to blow up.

The new strategy allows post deployment migrations to be skipped if the
env `SKIP_POST_DEPLOYMENT_MIGRATIONS` is provided.

```
SKIP_POST_DEPLOYMENT_MIGRATIONS=1 rake db:migrate
-> deploy app servers
SKIP_POST_DEPLOYMENT_MIGRATIONS=0 rake db:migrate
```

To aid with the generation of a post deployment migration, a generator
has been added. Simply run `rails generate post_migration`.
2018-10-08 15:47:38 +08:00

126 lines
3.0 KiB
Ruby

require 'rails_helper'
require_dependency 'migration/safe_migrate'
describe Migration::SafeMigrate do
before do
Migration::SafeMigrate::SafeMigration.disable_safe!
end
after do
Migration::SafeMigrate.disable!
Migration::SafeMigrate::SafeMigration.enable_safe!
end
def capture_stdout
old_stdout = $stdout
io = StringIO.new
$stdout = io
yield
io.string
ensure
$stdout = old_stdout
end
def migrate_up(path)
migrations = ActiveRecord::MigrationContext.new(path).migrations
ActiveRecord::Migrator.new(:up, migrations, migrations.first.version).run
end
it "bans all table removal" do
Migration::SafeMigrate.enable!
path = File.expand_path "#{Rails.root}/spec/fixtures/db/migrate/drop_table"
output = capture_stdout do
expect(lambda do
migrate_up(path)
end).to raise_error(StandardError)
end
expect(output).to include("rails g post_migration")
expect { User.first }.not_to raise_error
expect(User.first).not_to eq(nil)
end
it "bans all table renames" do
Migration::SafeMigrate.enable!
path = File.expand_path "#{Rails.root}/spec/fixtures/db/migrate/rename_table"
output = capture_stdout do
expect(lambda do
migrate_up(path)
end).to raise_error(StandardError)
end
expect { User.first }.not_to raise_error
expect(User.first).not_to eq(nil)
expect(output).to include("rails g post_migration")
end
it "bans all column removal" do
Migration::SafeMigrate.enable!
path = File.expand_path "#{Rails.root}/spec/fixtures/db/migrate/remove_column"
output = capture_stdout do
expect(lambda do
migrate_up(path)
end).to raise_error(StandardError)
end
expect(output).to include("rails g post_migration")
expect(User.first).not_to eq(nil)
expect { User.first.username }.not_to raise_error
end
it "bans all column renames" do
Migration::SafeMigrate.enable!
path = File.expand_path "#{Rails.root}/spec/fixtures/db/migrate/rename_column"
output = capture_stdout do
expect(lambda do
migrate_up(path)
end).to raise_error(StandardError)
end
expect(output).to include("rails g post_migration")
expect(User.first).not_to eq(nil)
expect { User.first.username }.not_to raise_error
end
it "supports being disabled" do
Migration::SafeMigrate.enable!
Migration::SafeMigrate.disable!
path = File.expand_path "#{Rails.root}/spec/fixtures/db/migrate/drop_table"
output = capture_stdout do
migrate_up(path)
end
expect(output).to include("drop_table(:users)")
end
describe 'for a post deployment migration' do
it 'should not ban unsafe migrations' do
user = Fabricate(:user)
Migration::SafeMigrate::SafeMigration.enable_safe!
path = File.expand_path "#{Rails.root}/spec/fixtures/db/post_migrate/drop_table"
output = capture_stdout do
migrate_up(path)
end
expect(output).to include("drop_table(:users)")
expect(user.reload).to eq(user)
end
end
end