rounding errors are not catched properly

[jlaurens]

Hi

almostEqual tests for absolute tolerance such that small values are always considered equal whereas big values are not.

With actual function

function almostEqual (left, right, tol) {
  return Math.abs(left - right) <= tol
}

the tests will pass when left === tol and right === 0 which may be weird, but is will not pass for big numbers.

Instead,

function almostEqual (left, right, tol) {
  return Math.abs(left - right) <= tol * (Math.abs(left)+Math.abs(right)+1) // the +1 for small
}

will pass only on rounding errors, whatever the magnitude of arguments is, either known in advance or not.

Thanks