Provide option for collect and merge all found configurations

It would be useful to provide the ability to continue searching and collecting configuration files, merging them together instead of finding one and stopping.

Something like this?: collectAndMerge: boolean, default: false

To make this a fully fledged feature it would also be great to provide two modifiers:

1. collectionFilter ( configs ) => configs, default: return configs
2. mergeStrategy ( configs ) => config, default: configs.reduce(( config, next ) => Object.assign(config, next))

The default order for priority of merge should probably be closest directory to furthest, first config found to last.

Like this:

/path/to/module/package.json { a: 1 }
/path/to/module/.modulerc { a: 2, b: 2 }
/path/to/.modulerc { a: 3, b: 3, c: 3 }
/.modulerc { a: 4, b: 4, c: 4, d: 4 }

{ a: 1, b: 2, c: 3, d: 4 }

This would mirror the .gitconfig pattern, where it loads the global config, and overrides it with the local directory config. Only this would be more powerful because you can collect directories in between, allowing organizational directories, etc.

[sudo-suhas]

@olsonpm I hear what you are saying. For me, it is 55:45 in favour of the feature. Because it would be nice to have this feature if somebody needs it. eslint is a good example of an use case. This was brought up earlier as well and the reason for not including it was that it was not clear what the logic for merging config files would be. Similar to the recent rewrite which added customisability, this could be done too.

[chrisblossom]

@one-humble-cranberry you can use cosmiconfig today without any changes needed. I’ve made a very basic example of how you can accomplish this: chrisblossom/cosmiconfig-all-example.