Unexpected behavior of Buffer.from( num.toString(16), "hex" )

[fider]

Info:
Version: v8.10.0
Platform: Windows 10, 64-bit
Subsystem: buffer module: Buffer.from

Code:

let hex_string = ('abc').toString(16);
let b = Buffer.from( hex_string, 'hex' );

Problem:
b == <Buffer ab> and I expect that b == <Buffer 0a bc>

Details and explanation:
When calling Buffer.from( ... , 'hex') with hex string that have odd number of characters (in case when no leading zero provided) I expect Buffer.from to add leading zero in case of hex encoding, so "1" will be recognized as "01".

Use case example:

Buffer.from( someNumber.toString(16), 'hex' ); 

I expect that in above example I do not have to append on my own leading "0" in case when toString(16) returns odd number of characters.

Other solution I see (instead of fixing Buffer.from) is to update toString(16), but in my opinion fix should implemented inside Buffer.from.

[vsemozhetbyt]

FWIW, this behavior seems documented:

• 'hex' - Encode each byte as two hexadecimal characters.

[bnoordhuis]

Yes, it's the documented behavior. 'hex' has always behaved this way and it's not something we'll change, that would be massively backwards incompatible.

[jrasanen]

I think Uint8Array from V8 does this conversion. So before calling it, we should do the left padding with zeroes?