Rails 5.1 run system tests and normal tests with one command

bin/rails test:system test

Specifying test:system before test will run both system and ordinary tests. The opposite order will only run the ordinary tests however.

rails test:all (Rails 6.1+)

Rails 6.1 introduces a new command - rails test:all.

It runs all test files in the test directory, including system tests.

Here is a link to PR. And also a link to the docs (please, scroll down to yellow box).