utimeSync truncates millisecond timestamps to nearest second

[srackham]

Deno statSync returns millisecond resolution but utimeSync truncates to seconds resolution.

Platform:

$ uname -a
Linux gnome-1804 4.15.0-99-generic #100-Ubuntu SMP Wed Apr 22 20:32:56 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

$ deno --version
deno 0.42.0
v8 8.2.308
typescript 3.8.3

In lieu of the REPL (#5063) I ran the following code:

const encoder = new TextEncoder();
const data = encoder.encode("foobar");

Deno.writeFileSync("test.txt", data);
console.log(`mtime: ${Deno.statSync("test.txt").mtime!.getTime()}`);
const newTime = 1588561654321;
console.log(`updating mtime to ${newTime}`);
Deno.utimeSync("test.txt", new Date(newTime), new Date(newTime));
console.log(`mtime: ${Deno.statSync("test.txt").mtime!.getTime()}`);

Output (the updated mtime is truncated to the nearest second):

mtime: 1588564365265
updating mtime to 1588561654321
mtime: 1588561654000

The Node.js utimesSync API does not exhibit this behaviour and sets millisecond timestamp resolution:

$ node --version
v13.14.0

$ node
Welcome to Node.js v13.14.0.
Type ".help" for more information.
> fs.writeFileSync('test.txt', 'foobar');
undefined
> fs.statSync('test.txt').mtime.getTime();
1588561704180
> fs.utimesSync('test.txt', new Date(1588561576064), new Date(1588561576064));
undefined
> fs.statSync('test.txt').mtime.getTime();
1588561576064
>