Support for sum and sumBy in compat layer

[dayongkr]

It will help for solving this #742 .

[raon0211]

Actually, I think we should support bigints in our original library. There is no easy way to handle them in native JavaScript. What do you think?

Of course, we need compatibility layers for sum and sumBy, too...

[dayongkr]

Actually, I think we should support bigints in our original library. There is no easy way to handle them in native JavaScript. What do you think?

Of course, we need compatibility layers for sum and sumBy, too...

I am not adding new functionality to Lodash.

Although handling of bigInt arrays is not explicitly mentioned in Lodash’s test cases, it is already supported due to the way its internal implementation works.

[dayongkr]

If it’s about performing calculations with a mix of number and bigInt, I also agree that it would be better to add this functionality to the original library!

[raon0211]

Actually, we intentionally don't mix numbers and bigints in JavaScript; for example, 0 + 1n throws. So we should exclusively handle arrays which have only numbers or only bigints.

I thought handling bigint arrays in the original sum function was needed...

[dayongkr]

It seems like I misunderstood the intention of the first question. If you’re asking whether the feature that handling an array with a single type(number or bigint) is needed in our original library, I agree.

At first, I’ll implement the compatibility version, and if no one else attempts to implement it in original version, I’ll add it to the original library tomorrow.

[dayongkr]

Actually, we intentionally don't mix numbers and bigints in JavaScript; for example, 0 + 1n throws. So we should exclusively handle arrays which have only numbers or only bigints.

I thought handling bigint arrays in the original sum function was needed...

I momentarily overlooked that it was big"int". So, I thought you were asking for a feature to perform typecasting and calculations, but I made a brief mistake.