add --create flag

[tradiff]

Improve the initial setup experience by allowing the user to run bundle exec turbo_tests --create to create the databases. Also add documentation regarding this new onboarding process. This may help with #12 being less of a hurdle for users coming over from parallel_tests, as well as brand new users.

[ilyazub]

@travistx Thank you for your contribution and for explaining the DX problem!

What if we'll just update the documentation like in my comment below?

[ilyazub]

I'm not sure if it should be added to the Runner.

I understand it'd be nicer to reduce the number of steps on the user side. But in this case, it seems, that wrapping two commands in a bash/rake command fits better.

[ilyazub]

Create test databases before running tests

1. Start TEST_ENV_NUMBER from 1

export PARALLEL_TEST_FIRST_IS_1=true

2. Create databases

bundle exec rake db:create RAILS_ENV=test

[tradiff]

That doesn't create the necessary test databases. That will just create a single "_test" database, not one database per cpu.

Here is your suggestion:

❯ export PARALLEL_TEST_FIRST_IS_1=true
❯ bundle exec rake db:create RAILS_ENV=test
Database 'myapp_test' already exists

Here is my suggestion with this PR:

❯ bundle exec turbo_tests --create
Database 'myapp_test5' already exists
Database 'myapp_test9' already exists
Database 'myapp_test10' already exists
Database 'myapp_test1' already exists
Database 'myapp_test3' already exists
Database 'myapp_test7' already exists
Database 'myapp_test8' already exists
Database 'myapp_test6' already exists
Database 'myapp_test2' already exists
Database 'myapp_test4' already exists

The way to do this without any changes to turbo_tests is first install the parallel_test gem as a direct dependency, and then run this:

❯ export PARALLEL_TEST_FIRST_IS_1=true
❯ bundle exec rake parallel:create
Database 'myapp_test3' already exists
Database 'myapp_test1' already exists
Database 'myapp_test9' already exists
Database 'myapp_test2' already exists
Database 'myapp_test8' already exists
Database 'myapp_test5' already exists
Database 'myapp_test6' already exists
Database 'myapp_test10' already exists
Database 'myapp_test4' already exists
Database 'myapp_test7' already exists

But the problem with this is it it requires having the parallel_tests gem installed as a direct dependency. And this is a direct dependency that is only used for the purpose of this one-time command. With my PR, the user is no longer required to install parallel_tests as a direct dependency. They can just install turbo_tests which acts as their gateway to parallel_tests.

[bf4]

seems reasonable to document this even if not done automatically?

[rsanheim]

any word on this? seems like a worthwhile addition that will make first time setup easier

[pboling]

It looks like this gem is going to have parallel_tests as a direct hard dependency going forward, but regardless this would still be useful to keep the commands within the same namespace, as it is odd to use some commands of parallel_tests, and others of turbo_tests.