Why is there an underflow fault in BigNumber if value % 1 == true?

[regexyl]

I've been using BigNumber.from() to convert integers to BigNumbers, but they all throw an error except for BigNumber.from(0).

The errors thrown are all the same regardless of the integer input:

Error: underflow (fault="underflow", operation="BigNumber.from", value=0.6931471805599453, code=NUMERIC_FAULT, version=bignumber/5.2.0)

The conversions that have caused this underflow error are, e.g.:
BigNumber.from(100);
BigNumber.from("100");
BigNumber.from("1e18")

I'm not too sure what is causing this issue. Is it due to the following line of code below? And why does L244 of bignumber.ts throw an underflow fault if value % 1 == true?

// bignumber.ts

if (typeof(value) === "number") {
    if (value % 1) { // why?
        throwFault("underflow", "BigNumber.from", value);
    }

    if (value >= MAX_SAFE || value <= -MAX_SAFE) {
        throwFault("overflow", "BigNumber.from", value);
    }

    return BigNumber.from(String(value));
}

Thanks for your help! :)

[ricmoo]

Are you sure those first two are causing underflow? I can use your first two examples and they work fine. The BigNumber class does not handle e-notation (it can be confused with hex too easily, although that might be relaxed in the future).

The underflow error you are getting indicates you are passing 0.6931471805599453 into it, which is indeed an arithmetic underflow error. Use console.log before your calls to BigNumber.from To verify you are passing in what you think you are. Hoisting and masking might mean you are calling it with unexpected values.

[ricmoo]

(The v % 1 is equivalent to the C fmod which can be used to determine if there is a non-integer component in the IEEE 754 JavaScript number; it will be true if the mantissa has non-zero components inside the exponent’s base)

[regexyl]

Thanks @ricmoo , that cleared things up! I just realized it was calling an external rogue function which was trying to convert Math.LN2 into a BigNumber (that resulted in the 0.6931471805599453 value). I should have gone deeper into the error logs.