macOS append mode test

append.js

var fs = require("fs");
console.log(process.version);
var f = fs.openSync("testfile", "w");
fs.writeSync(f, "a=1\nb=2\n");
fs.closeSync(f);
f = fs.openSync("testfile", "a");
fs.writeSync(f, new Uint8Array([99, 61, 51]), 0, 3, 8);
fs.closeSync(f);
var result = fs.readFileSync("testfile", { encoding: "utf-8" });
var success = result === "a=1\nb=2\nc=3";
console.log(result, success ? "success" : "failure");