feat(sum,sumBy): add a feature handling bigint values to original library

[dayongkr]

Overview

I added the feature to original library.

If the array is empty, it is impossible to distinguish between bigint and number, so I implemented it to always return 0 when the array is empty.

Therefore, in the overloading signature of sumBy, it is specified that if the return type of getValue is bigint, the function may return either a bigint or a number.

close #742

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Name	Status	Preview	Comments	Updated (UTC)
es-toolkit	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Oct 30, 2024 1:33am

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.13%. Comparing base (247fb77) to head (0be3f57).

Additional details and impacted files

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  Coverage   99.13%   99.13%           
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  Files         296      296           
  Lines        2645     2649    +4     
  Branches      772      774    +2     
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+ Hits         2622     2626    +4     
  Misses         22       22           
  Partials        1        1           

[dayongkr]

After discussing it in the Discord channel, we decided not to support BigInt in our sum and sumBy functions.

Instead, we’ll implement separate functions, such as sumBigInt and sumBigIntBy.

Here’s why:

We want to maintain a property like sum([a,b,c]) + sum([d,e,f]) === sum([a,b,c,d,e,f]).
However, with BigInt support, this property would break.
For example, sum([]) + sum([1n,2n]) would throw an error, while sum([...[], ...[1n,2n]]) would return 3n, thus violating the intended property.