[jcranmer]

In practice, JavaScript has 32-bit signed integers and 64-bit floating-point numbers as distinct types (look into any JS engine, and you'll see a distinction between the two being made), even if they both surface as a single "number" type. You can also see the distinction in the way that bitwise operators coerce numbers to integers, even though the arithmetic operators coerce to floats in theory.

[recursive]

The spec describes the behavior of converting to and from 32-bit signed for the purposes of the bitwise operators. https://tc39.es/ecma262/#sec-toint32