Allow scenarios without dependency changes

[trentmwillis]

Currently, the ScenarioManager checks to ensure that there are dependency managers which are only created if you specify some sort of dependency change in your scenarios.

However, I have a use-case where I would like to run multiple different scenarios without changing any dependencies. This currently results in a No dependency manager adapter error being thrown. I can workaround this by specifying an empty dependency change (e.g., npm: {}), but this feels hacky.

So, I have two questions:

1. Why is there a requirement that dependency managers must be present currently?
2. Can we remove that requirement? It seems like answer should be yes since I can hack around it now anyway.

[rwjblue]

Yes. It should not be required. It makes sense to have various scenarios (possibly with the project default deps) for different commands and stuff.

[trentmwillis]

Sounds good, will open a PR then.

[kategengler]

@trentmwillis Is this still desired?

[trentmwillis]

I found a way to do what I want, but I feel like this could still be beneficial, just haven't had the time to do it

[rwjblue]

I believe this is possible now (and a scenario without dependency changes is part of the default addon blueprint).

Closing...

[kategengler]

I think what was meant was a scenario without either npm or bower. @mixonic also asked about this recently in slack.

[trentmwillis]

Yes, the original issue was to have different scenarios (say with different commands), but without any dependency changes.

[mixonic]

Specifically I've found myself in the ember-resolver and in a client app wanting to run scenarios that are based on ENV variables. No dependencies to change, just different commands to run.

[rwjblue]

Hmm. I guess I don't fully grok what y'all mean.

The following config does not do any dependency changes and has a custom command per-scenario:

module.exports = [
  { 
    name: 'default',
    command: 'ember test'
    npm: {},
    bower: {}
  },
  { 
    name: 'special-sauce',
    command: 'SPECIAL_SAUCE=true ember test'
    npm: {},
    bower: {}
  }
]

What am I missing?

[rwjblue]

(reopening because it seems that I must be misunderstanding...)

[trentmwillis]

@rwjblue your example is correct, but you should able to do this without needing to specify npm or bower fields. In other words, you should be able to specify a scenario like so without an error:

{ 
  name: 'special-sauce',
  command: 'SPECIAL_SAUCE=true ember test'
}

[rwjblue]

AHA! OK! Sorry, I was over-focusing on the fact that it was possible and didn't realize we were mostly just talking about the ergonomics. Turns out that it is important to read the actual description fully 😞 . Sorry for the run around...

I think we can just remove the error when there are no managers: #143.

[trentmwillis]

No worries! Thanks for opening the PR :)