> It has the same fundamental function.

No, it doesn't.

> JS just has the concept of "false-ish", which you'll likely already know as a JS developer.

Ruby has a concept of false-ish (which is narrower than JS’s), but Ruby’s “compact” isn't about false-ish-ness, Filtering out false-ish values is .select(&:itself), not .compact

Maybe my feelings here are colored by PHP being my primary lang, but I read both functions purpose as "remove the empty values from this array" with a language-level difference on what "empty" is defined as. PHP's "empty" includes both nulls and false-y values.

Whether you want to call it the "same" function or "similar" function, lodash's excellent docs reveal its functionality quite handily if someone's confused by it.

The ruby method removes "nil", not "false". The ruby method has absolutely nothing to do with false whatsoever, while lodash makes explicit reference to it. The ruby method is intended to just remove holes in arrays, not remove values. JavaScript has the concept of holes in arrays, but that's not what the lodash function is about.

They're 2 different functions/methods with 2 different ideas behind them. They're absolutely not each other's equivalent in their respective language.