Votes aren't tests

5,572 votes didn't tell me whether a rounding fix was safe for prices.

Stack Overflow's top rounding answer offers an EPSILON option to make cases like 1.005 round correctly.

I ran it on 10,000 half-cent amounts, from 0.005 to 99.995, in node 20. Each is exactly halfway between two cents. I used round half up, with the expected result computed from the decimal string.

557 rounded too low. The plain formula got 572 wrong. A different formula got 0 wrong on the same set.

Limits: node 20 only; positive half-cent amounts; round half up. I didn't test other engines, negatives, non-midpoints or banker's rounding.

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