Rxjs: Why is the pluck deprecated?

[jakovljevic-mladen]

I saw this commit and I'm wondering why pluck is deprecated? I couldn't find any issue where this is discussed.
By the logic behind the explanation about using optional chaining, this means that you can easily deprecate lot's of other simple operators like startWith, endWith, timestamp and so on, because it's always possible to use pipe + something in case of these. I just wonder what's the reason behind deprecating this operator.

[kolodny]

pluck('prop') is a shorthand for map(x => x.prop), the main advantage to using pluck was the path traversal safety, meaning you can do

pluck('foo', 'bar', 'baz')

and this would be fine even if the emitted value didn't have a foo property. Contrast this with
map(x => x.foo.bar.baz) which will error if the emitted value doesn't have a foo property

With optional chaining this advantage is no longer true since you can now do

map(x => x?.foo?.bar?.baz)

And it will be as safe as the pluck usage. Note that having proper TypeScript typing for pluck is quite complex and not as robust as the map usage which is a major reason to prefer the map method

[cartant]

FWIW, deprecated parts of the API won't necessarily be removed in the very next major version of the library. ATM, one of the things on which we are working is improving the deprecation messages to make them easier to understand and to include links to the documentation to explain what is being deprecated and when it's likely to be removed. IMO, pluck won't be removed from the API until version 8 or later.

[jakovljevic-mladen]

Thanks for the clarifications @kolodny, @cartant. I like this operator and I use it a lot because it's easier (and more clean IMO) to write pluck than map.