Fix aggregate group id

[davimacedo]

Close #5989

[davimacedo]

@dplewis I will still add a test case.

[davimacedo]

@dplewis it should be good now

[codecov]

Codecov Report

Merging #5994 into master will decrease coverage by 0.02%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #5994      +/-   ##
==========================================
- Coverage   93.68%   93.65%   -0.03%     
==========================================
  Files         156      156              
  Lines       10926    10926              
==========================================
- Hits        10236    10233       -3     
- Misses        690      693       +3

Impacted Files	Coverage Δ
src/Adapters/Storage/Mongo/MongoStorageAdapter.js	92.23% <100%> (-0.71%)	⬇️
src/RestWrite.js	93.56% <0%> (ø)	⬆️

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[acinader]

this is funny and could be an advertisement against javascript :).

this solution looks good to me, but is hard to read.

Here's my take at a test that is easier to read:

_.isNil(v) || _.isEmpty(v) && !_.isNumber(v);

here's a test of it: https://runkit.com/arthur/reallyempty

def not asking you to change it, but I just couldn't resist trying to futz with it ;).

I'd be surprised if there isn't a more concise test, but I tried.

[davimacedo]

It is really weird. What we want to do in that line is actually return null if:

• it is null
• it is undefined
• it is an empty string
• it is an object with no keys
• it is an array with no elements

I suspect there is no beautiful way to do this :)

Your solution fails for boolean. Se here: https://runkit.com/adavimacedo/5d6ca8163db2fb001a475448