Modernise some JS

[ChrisLane]

• Use const wherever possible
• Use arrow functions since they're a bit cleaner looking
• Use .then instead of await. await is cleaner in some cases but using it everywhere seems a bit silly, making everything synchronous :P

Side note: csv not being immutable, needing to load the file twice due to filtering/mapping operations is annoying #ImmutableByDefault

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[ChrisLane]

Obviously this is personal preference. :shrug:

[mishajw]

Side note: csv not being immutable, needing to load the file twice due to filtering/mapping operations is annoying #ImmutableByDefault

Hmm, not sure if the CSV objects are mutable or not, but I don't think we modify them at all. AFAIU, the filter/map/etc. functions are the standard list functions, and don't mutate the underlying object. We only load each CSV once though - there are two, latest.csv and line.csv - maybe that's the problem you saw?

[ChrisLane]

Side note: csv not being immutable, needing to load the file twice due to filtering/mapping operations is annoying #ImmutableByDefault

Hmm, not sure if the CSV objects are mutable or not, but I don't think we modify them at all. AFAIU, the filter/map/etc. functions are the standard list functions, and don't mutate the underlying object. We only load each CSV once though - there are two, latest.csv and line.csv - maybe that's the problem you saw?

Ah yep, I read them both as being latest.csv so that will have been the issue, however, filter will return a new collection but the objects within that collection still reference the same as before I think. If it's just primitives then the whole thing will be new.

[ChrisLane]

WOOP WOOP! :tada: