The `assert_serializer` test helper was added in 0.9.0.apha1[1],
and was not included in 0.10.
This patch brings back the `assert_serializer` test helper. This is the last
revision[2] that has the helper. The original helper was used as base.
[1]: https://github.com/rails-api/active_model_serializers/pull/596
[2]: 610aeb2e92
- Create the AssertSerializer
- Use the Test namespace
- Make the tests pass on the Rails master
- Rails 5 does not include `assert_template` but we need this on the tests of
the helper.
- This add the `rails-controller-testing` to keep support on `assert_template`.
- Only load test helpers in the test environment
c0b99c980c