internal.computeValue() throws if keys is not present under certain circumstances

[saadtazi]

Repro step:

// this works
mingo._internal().computeValue({l1: {l2: [{l3: [{ a: 666}]}]}}, '$l1.l2.l3.a');

// this throws an exception
mingo._internal().computeValue({l1: {l2: [{l3: [{ a: 666}]}, {l4: 'some prop'}]}}, '$l1.l2.l3.a');

Thrown exception:

TypeError: Cannot read property 'a' of undefined
    at getValue (path/to/project/node_modules/mingo/dist/mingo.js:3545:13)
    at _loop (path/to/project/node_modules/mingo/dist/mingo.js:3617:15)
    at resolve (path/to/project/node_modules/mingo/dist/mingo.js:3625:16)
    at path/to/project/node_modules/mingo/dist/mingo.js:3605:16
    at Array.map (native)
    at _loop (path/to/project/node_modules/mingo/dist/mingo.js:3604:21)
    at resolve (path/to/project/node_modules/mingo/dist/mingo.js:3625:16)
    at Object.computeValue (path/to/project/node_modules/mingo/dist/mingo.js:3840:12)
    at repl:1:19
    at sigintHandlersWrap (vm.js:22:35)

It seems like computeValue is trying to find a property a in 'some prop'.

[kofrasa]

Thanks for the report.

Looks like a validation bug in the resolve() function most likely from not returning early given null or undefined input.

Maybe you can take a stab at this too if you are keen.