Feature request: query-string strip (`pick`, `exclude`)

[zhangciwu]

To eliminate unneeded params, preserve only needed

queryString.strip('http://example.com/?a=1&b=2', [ 'a' ] )
// result : http://example.com/?a=1

It would be helpful when page has many redudant params (like statistic params) and want to get a cleaner one

---

Better function names from @Uzlopak:

queryString.pick('http://example.com/?a=1&b=2', [ 'a' ] )
// result : http://example.com/?a=1


queryString.exclude('http://example.com/?a=1&b=2', [ 'a' ] )
// result : http://example.com/?b=2

[Uzlopak]

strip is not a very obvious naming. Do you keep the ones you name or do you drop the ones you name?

pick or exclude should better names for this type of operation.

[zhangciwu]

@Uzlopak strip is inspired by python string strip (remove spaces at two ends)
this word means 'remove all coverings from.'

And yes, it's not suit for exact function name for its inaccuracy，pick or exclude are better choices. (Maybe both can be implement)

[Uzlopak]

The python strip equivalent in javacscript would be trim

[sindresorhus]

I would name it .removeElements()

[zhangciwu]

For a better implementation, this could preserve the order of url queries, cause input and output are both strings, which has order.

[Uzlopak]

I would still prefer pick and exclude as removeElements could imply that you make not an idempotent operation.

[BenoitSerrano]

Just opened a PR here that provides what you want : #261 ;)

[zhangciwu]

@BenoitSerrano Good job! How about considering the order?

For a better implementation, this could preserve the order of url queries, cause input and output are both strings, which has order.

[Uzlopak]

@zhangciwu
@BenoitSerrano

I read the code, and I think it is reversing the order, by doing

return Object.assign({[currentKey]: query[currentKey]}, accumulator);

To conserve the order I suppose you would actually have to do it the other way round.

like
return Object.assign(accumulator, {[currentKey]: query[currentKey]});
or
return Object.assign({}, accumulator, {[currentKey]: query[currentKey]});

But i didnt test it...

[zhangciwu]

@Uzlopak In ES2020 Object do preserve insertion order, but early versions(ES3/5/6-2019) there is no limitation (or partial limitation), so it may have different result for different browser/node/other runtime

With this proposal, under most circumstances, for..in, Object.keys / values / entries, and JSON.stringify are guaranteed to iterate in order over:
(1) Numeric array keys
(2) non-Symbol keys, in insertion order
(3) Symbol keys, in insertion order

Relate: https://stackoverflow.com/questions/30076219/does-es6-introduce-a-well-defined-order-of-enumeration-for-object-properties

[BenoitSerrano]

Updated it, it now preserves the parameters order ;)

[Uzlopak]

looks good for me