Add clarifying comment in RoundNumberToIncrementAsIfPositive

ptomato · Ms2ger · commit d852c7daa9b4 · 2025-05-02T17:16:25.000+02:00
While going over this code I was very confused by this line. I've added
a comment to explain it.
diff --git a/polyfill/lib/ecmascript.mjs b/polyfill/lib/ecmascript.mjs
@@ -4038,6 +4038,8 @@ export function RoundNumberToIncrementAsIfPositive(quantity, increment, mode) {
     r1 = quotient;
     r2 = quotient.add(1);
   }
+  // Similar to the comparison in RoundNumberToIncrement, but multiplied by an
+  // extra sign to make sure we treat it as positive
   const cmp = remainder.times(2).abs().compare(increment) * (quantity.lt(0) ? -1 : 1);
   const even = r1.isEven();
   const rounded = quotient.times(increment).eq(quantity)

Original file line number	Diff line number	Diff line change
`@@ -4038,6 +4038,8 @@ export function RoundNumberToIncrementAsIfPositive(quantity, increment, mode) {`
`4038`	`4038`	`r1 = quotient;`
`4039`	`4039`	`r2 = quotient.add(1);`
`4040`	`4040`	`}`
	`4041`	`+ // Similar to the comparison in RoundNumberToIncrement, but multiplied by an`
	`4042`	`+ // extra sign to make sure we treat it as positive`
`4041`	`4043`	`const cmp = remainder.times(2).abs().compare(increment) * (quantity.lt(0) ? -1 : 1);`
`4042`	`4044`	`const even = r1.isEven();`
`4043`	`4045`	`const rounded = quotient.times(increment).eq(quantity)`