Run results for: Uint8Array to String

Test name	Executions per second
✓ strapply_strconcat	5,256 Ops/sec
strapply_arrconcat	5,225 Ops/sec
strapply_arrpush	4,640 Ops/sec
strspread_arrconcat	373 Ops/sec
strspread_arrpush	369 Ops/sec
strspread_strconcat	368 Ops/sec

Script Preparation code:

uint8Array = Uint8Array.from([...Array(2 ** 16)].map(() => Math.floor(Math.random() * (2 ** 8))));
CHUNK_SZ = 0x8000;

function strapply_arrpush(uint8Array) {
  const c = [];
  for (let i = 0; i < uint8Array.length; i += CHUNK_SZ) {
    c.push(
      String.fromCharCode.apply(null, uint8Array.subarray(i, i + CHUNK_SZ))
    );
  }
  return c.join("");
}

function strapply_arrconcat(uint8Array) {
  let c = [];
  for (let i = 0; i < uint8Array.length; i += CHUNK_SZ) {
    c = c.concat(
      String.fromCharCode.apply(null, uint8Array.subarray(i, i + CHUNK_SZ))
    );
  }
  return c;
}

function strapply_strconcat(uint8Array) {
  let s = "";
  for (let i = 0; i < uint8Array.length; i += CHUNK_SZ) {
    s += (
      String.fromCharCode.apply(null, uint8Array.subarray(i, i + CHUNK_SZ))
    );
  }
  return s;
}

function strspread_arrpush(uint8Array) {
  const c = [];
  for (let i = 0; i < uint8Array.length; i += CHUNK_SZ) {
    c.push(
      String.fromCharCode(...uint8Array.subarray(i, i + CHUNK_SZ))
    );
  }
  return c.join("");
}

function strspread_arrconcat(uint8Array) {
  let c = [];
  for (let i = 0; i < uint8Array.length; i += CHUNK_SZ) {
    c = c.concat(
      String.fromCharCode(...uint8Array.subarray(i, i + CHUNK_SZ))
    );
  }
  return c;
}

function strspread_strconcat(uint8Array) {
  let s = "";
  for (let i = 0; i < uint8Array.length; i += CHUNK_SZ) {
    s += (
      String.fromCharCode(...uint8Array.subarray(i, i + CHUNK_SZ))
    );
  }
  return s;
}

Tests:

strapply_arrpush
strapply_arrpush(uint8Array)
strapply_arrconcat
strapply_arrconcat(uint8Array)
strapply_strconcat
strapply_strconcat(uint8Array)
strspread_arrpush
strspread_arrpush(uint8Array)
strspread_arrconcat
strspread_arrconcat(uint8Array)
strspread_strconcat
strspread_strconcat(uint8Array)

Run results for: Uint8Array to String

Benchmark of various methods used to convert a Uint8Array to a string value

strapply_arrpush

strapply_arrconcat

strapply_strconcat

strspread_arrpush

strspread_arrconcat

strspread_strconcat