Add a query method to allow chaining from ember-pouchdb/query

[guillett]

First, thanks a lot for the tool set you put together.

I feel like query in ember-pouch is broken. I amend your tests and the relational context is lost (querying smasher also returns tacoSoup)
cf.

• https://github.com/guillett/ember-pouch/commit/c26990553795099e5ec3526886072eeaeb09250b and
• https://travis-ci.org/guillett/ember-pouch/builds/188955834

This issue lead me here where I would like to add a query method to call from ember-pouchdb instead of the db.find() which can returned not relationally valid data.

I am currently giving it a go and will probably create a PR soon.

[broerse]

Not sure if this test is bitten by a ember-data bug with coalesceFindRequests: true

emberjs/data#4463

Perhaps test with coalesceFindRequests: false to check if this is the case. See https://github.com/jlami/ember-bug-empty-data/blob/master/app/adapters/application.js#L5

If this is not the bug looking forward to a PR.

[guillett]

I had another look and try to add a query method. However, my knowledge base in CouchDB and my time are too limited at the moment.

As said previously, I have a test case there (https://github.com/guillett/ember-pouch/commit/c26990553795099e5ec3526886072eeaeb09250b?w=0).

Naively, I tried to use start/end keys to limit the search to a given type (working part of findAll) and a selector (working part of query) but I didn't manage to make that work.

I shamelessly put my attempt there (https://github.com/guillett/relational-pouch/commit/1e761268e7108ea2270d71291dd1c018a9eea580).

Happy to get feedback and guidance.
Thanks,

[afinne]

I just realised that there have been discussions on this in #3 also.