find location of packages outside of node_modules, support packages without package.json

[JeroenVinke]

fixes #567

@AStoker i'd like to hear your thoughts on the following. We need the root folder of a package (kept in description.location and looks something like c:/development/my-app/node_modules/my-plugin/) for two things:

1. to look for (and read) the package.json of the package (which is used to determine the loader configuration)
2. to determine what bundle to put files in. In other words, to prevent files from ending up in app-bundle.js when they should have ended up in vendor-bundle.js (or other)

Currently the root folder of packages inside the node_modules folder is determined as follows. You resolve the path of the package (as defined in aurelia.json) which could be c:/development/my-app/node_modules/my-plugin/dist/ and traverse up the folder tree until you hit the node_modules. The path until the first segment after node_modules is then used as the package root folder (c:/development/my-app/node_modules/my-plugin).

When you keep packages outside the node_modules folder, this trick does not work because there is no standard folder name like node_modules to look for in the path. So as far as I know there is no reliable way of knowing what the root folder of the package is when the package is not inside the node_modules folder.

So this PR enforces that if you define dependencies outside the node_modules folder, that you must define a packageRoot :

          {
            "name": "jquery",
            "path": "../external_modules/jquery/dist",
            "packageRoot": "../external_modules/jquery",
            "main": "jquery.min"
          }

[AStoker]

I like that idea. I won't have time to really look into it until Monday though (gone over the weekend). So in your example, it would search up external_modules the same way it would search up node_modules?

[JeroenVinke]

It wouldn't traverse the directory tree to find the package root like it does with node_modules as that's not necessary when the user defines the packageRoot in aurelia.json

[AStoker]

Gotcha, I'm tracking now. Sounds reasonable to me!

[JeroenVinke]

@EisenbergEffect I believe this is good to go.

I decided to add another fix to this PR, because they depend on each other. So this fixes:

• Error when bundling resources from outside node_modules #567
• Support packages without package.json file #575

When you merge this, could you also merge aurelia/framework#762?

[AStoker]

@EisenbergEffect, sorry to bump. Could we get this in?