feat(Ignitor): allow to set modulesRoot

[targos]

Proposed changes

Sometimes, appRoot is not necessarily the directory which contains
node_modules (for example when the AdonisJs app is in a subdirectory
of a bigger application.
ignitor.modulesRoot(location) allows to specify a different directory to
look for dependencies such as @adonisjs/ace.

Types of changes

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• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

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• I have read the CONTRIBUTING doc
• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works.
• I have added necessary documentation (if appropriate)

[targos]

Documentation PR: adonisjs/legacy-docs#290

[coveralls]

Coverage increased (+0.6%) to 93.827% when pulling 7e61fae on targos:modules-root into 8d4417b on adonisjs:develop.

[thetutlage]

Do you think, we should also change this line?

adonis-ignitor/src/Ignitor/index.js

Line 149 in 7e61fae

this._packageFile = require(path.join(this._appRoot, 'package.json'))

If your adonis code is not a separate app, I believe it will not have a package.json file too?

[targos]

@thetutlage I'm hesitant about this one. The package.json is used to put the "autoload" field for the app. It seemed weird to me to have this configuration element outside of appRoot.

For example, in the app I am developing, I created a second package.json just for this:

{
  "private": true,
  "name": "api",
  "autoload": {
    "App": "./app"
  }
}

This is not ideal, but the other way of doing it would mean that one cannot have two Adonis apps with a different autoload config. Perhaps that's a limitation that just needs to be accepted as such...

[thetutlage]

but the other way of doing it would mean that one cannot have two Adonis apps

Having 2 Adonis apps sharing the same underlying dependencies will not help much either, since they both will be using the same IoC container.

But I do get your point and it's fine to keep that line as it is.