nextPage/previousPage -- console.log('2' + 1) vs console.log('2' - 1) discussion.

[jeremym]

A developer on my current project had the task of building out a core table for us to reuse. The code was clean; everything worked great; overall we are very happy with this table (compared to some tables I've used during my 7-year love affair with React).

A bug came up and the cause wasn't quite evident.

• His nextPage button was sometimes broken -- previousPage worked fine; nextPage would fail, but only if not preceded by a previousPage). The cause was 2-fold (well, 3 fold if you count the fact that TS probably would have identified the issue immediately -- this particular project isn't one of our TS projects).

1. His goToPage Select component was using event.target.value (a string), which works fine (but, sets paginationTableState's pageIndex to a string value, like "5").

2. previousPage and nextPage setPageIndex internal functional update doesn't coerce that current page state value to a base-10 number.

  previousPage: () => {
    return table.setPageIndex(old => old - 1)
  },

  nextPage: () => {
    return table.setPageIndex(old => {
      return old + 1
    })
  },

I just looked to see the type on pageIndex in PaginationState, and sure enough, pageIndex: number (so we would have gotten a warning about this on our Typescript projects), but would there be harm in coercing old to a number in gotoPage, or even to take all functionalUpdaters, when executed, and coerce the returned value into a base 10 number? (nobody is using HEX values for page indexes are they?)

The overloading of the + in JS was the reason previousPage worked and nextPage didn't:

console.log('2' + 1); // output = 21
console.log('2' - 1); // output = 1

Again... all of this isn't an issue for typescript projects, and it did cause some good discussions with our dev team, but I thought I'd point it out, and wouldn't mind hearing some thoughts on the functionalUpdate pattern on this project.

Love the code when glancing through it -- so easy to read and understand quickly. Great job!!