Prefer Lodash get

[GLosch]

The problem

In code reviews, a common request is to use Lodash _.get in place of referencing deeply nested data structures like foo.bar.moreFoo.moreBar to avoid potential JavaScript errors that would break the page. Implementing the prefer-get rule here would take care of this.

[rfarine]

No qualms with this at all. Sounds good to me. 👍

[kangax]

How deep is too deep or would that be determined on a per-project basis?

[GLosch]

default depth is 3, which sounds like a reasonable baseline to me

[kangax]

I'm generally for it although to play devil's advocate:

1. deep nesting could be an indication of a code smell (code reaching "far beyond" its concerns/responsibilities; law of Demeter)
2. if the errors are swallowed silently, it's not always a good thing

Having said that, there's definitely valid cases for deep access (e.g. retrieving something from a dumb but deeply nested data structure) where get could be useful.

One more thing — in our codebase I see quite a few occurrences of triple nesting such as
this.props.fetchChurnItems(...), state.churnItems.loading, props.currentLocation.uuid, and so on. I wouldn't want any of these wrapped in _.get. It feels like I'd want to use _.get in very specific cases where there's 4+ nesting and only on a pure data structure.

[GLosch]

Yeah, great points, @kangax. For some added context, the use case that brought this up in the first place was our Contentful entries. A common resource like a hero image url could come back nested as follows: fields.section.fields.background.fields.file.url.

...and that's following normal practices for Contentful data modeling.

Error handling/alerting is a different question though, and probably something better left to the application engineers to determine.

[GLosch]

re: that thread in quincy-2337, it would be great if this lint config also enforced importing lodash as _ and using functions prefixed with _, e.g. _.get() instead of importing the named function and using it like get()

[nason]

Thats a slightly different conversation @GLosch -- this one is talking about preferring get for lookups in deeply nested objects.

What you're talking about is importing the whole lodash module vs importing specific modules as necessary. I disagree with you on this one -- let's open up a new issue to discuss?

[nason]

Opened #5 for that discussion ^ /cc @GLosch @thinkaxelthink

[GLosch]

awesome, thanks