unicorn/numeric-separators-style Style
What it does
Enforces a convention of grouping digits using numeric separators.
Why is this bad?
Long numbers can become really hard to read, so cutting it into groups of digits, separated with a _, is important to keep your code clear. This rule also enforces a proper usage of the numeric separator, by checking if the groups of digits are of the correct size.
Example
javascript
const invalid = [1_23_4444, 1_234.56789, 0xab_c_d_ef, 0b10_00_1111, 0o1_0_44_21, 1_294_28771_2n];
const valid = [1_234_567, 1_234.567_89, 0xab_cd_ef, 0b1000_1111, 0o10_4421, 1_294_287_712n];