How to handle the endianness with UInt8 in a DataView?

Question

It seems like there is nothing to handle endianness when working with UInt8. For example, when dealing with UInt16, you can set if you want little or big endian:

dataview.setUint16(byteOffset, value [, littleEndian])

vs

dataview.setUint8(byteOffset, value)

I guess this is because endianness is dealing with the order of the bytes and if I'm inserting one byte at a time, then I need to order them myself.

So how do I go about handling endianness myself? I'm creating a WAVE file header using this spec: http://soundfile.sapp.org/doc/WaveFormat/

The first part of the header is "ChunkID" in big endian and this is how I do it:

dataView.setUint8(0, 'R'.charCodeAt());
dataView.setUint8(1, 'I'.charCodeAt());
dataView.setUint8(2, 'F'.charCodeAt());
dataView.setUint8(3, 'F'.charCodeAt());

The second part of the header is "ChunkSize" in small endian and this is how I do it:

dataView.setUint8(4, 172);

Now I suppose that since the endianness of those chunks is different then I should be doing something different in each chunk. What should I be doing different in those two instances?

Cheers!

EDIT

I'm asking this question, because the wav file I'm creating is invalid (according to https://indiehd.com/auxiliary/flac-validator/). I suspect this is because I'm not handling the endianness correctly. This is the full wave file:

const fs = require('fs');

const BITS_PER_BYTE = 8;
const BITS_PER_SAMPLE = 8;
const SAMPLE_RATE = 44100;
const NB_CHANNELS = 2;
const SUB_CHUNK_2_SIZE = 128;

const chunkSize = 36 + SUB_CHUNK_2_SIZE;
const blockAlign = NB_CHANNELS * (BITS_PER_SAMPLE / BITS_PER_BYTE);
const byteRate = SAMPLE_RATE * blockAlign;

const arrayBuffer = new ArrayBuffer(chunkSize + 8)
const dataView = new DataView(arrayBuffer);

// The RIFF chunk descriptor
// ChunkID
dataView.setUint8(0, 'R'.charCodeAt());
dataView.setUint8(1, 'I'.charCodeAt());
dataView.setUint8(2, 'F'.charCodeAt());
dataView.setUint8(3, 'F'.charCodeAt());
// ChunkSize
dataView.setUint8(4, chunkSize);
// Format
dataView.setUint8(8, 'W'.charCodeAt());
dataView.setUint8(9, 'A'.charCodeAt());
dataView.setUint8(10, 'V'.charCodeAt());
dataView.setUint8(11, 'E'.charCodeAt());

// The fmt sub-chunk
// Subchunk1ID
dataView.setUint8(12, 'f'.charCodeAt());
dataView.setUint8(13, 'm'.charCodeAt());
dataView.setUint8(14, 't'.charCodeAt());
// Subchunk1Size
dataView.setUint8(16, 16);
// AudioFormat
dataView.setUint8(20, 1);
// NumChannels
dataView.setUint8(22, NB_CHANNELS);
// SampleRate
dataView.setUint8(24, ((SAMPLE_RATE >> 8) & 255));
dataView.setUint8(25, SAMPLE_RATE & 255);
// ByteRate
dataView.setUint8(28, ((byteRate >> 8) & 255));
dataView.setUint8(29, byteRate & 255);
// BlockAlign
dataView.setUint8(32, blockAlign);
// BitsPerSample
dataView.setUint8(34, BITS_PER_SAMPLE);

// The data sub-chunk
// Subchunk2ID
dataView.setUint8(36, 'd'.charCodeAt());
dataView.setUint8(37, 'a'.charCodeAt());
dataView.setUint8(38, 't'.charCodeAt());
dataView.setUint8(39, 'a'.charCodeAt());
// Subchunk2Size
dataView.setUint8(40, SUB_CHUNK_2_SIZE);
// Data
for (let i = 0; i < SUB_CHUNK_2_SIZE; i++) {
    dataView.setUint8(i + 44, i);
}

Answer 1

A single byte (uint8) doesn't have any endianness, endianness is a property of a sequence of bytes.

According to the spec you linked, the ChunkSize takes space for 4 bytes - with the least significant byte first (little endian). If your value is only one byte (not larger than 255), you would just write the byte at offset 4 as you did. If the 4 bytes were in big endian order, you'd have to write your byte at offset 7.

I would however recommend to simply use setUint32:

dataView.setUint32(0, 0x52494646, false); // RIFF
dataView.setUint32(4, 172       , true);
dataView.setUint32(8, 0x57415645, false) // WAVE