hexFrom in @ckb-ccc/core/barrel not producing valid hex strings when an empty array is provided

[Officeyutong]

console.log(hexFrom([])); // outputs "0x"
console.log(hexFrom(new Uint8Array([]))); // outputs "0x"

hexFrom will return 0x which is an invalid hex string when an empty array was provided as argument, since bytesTo returns empty string when zero-length bytes was provided.

Illegal hex string like 0x will be refused by BigInt and leads to an exception.

Minimum reproduce: https://github.com/Officeyutong/ckb-ccc-core-hex-from-reproduce

A PR has been made to fix this issue #90

[Officeyutong]

Not an issue. See #90 (comment)