Why a mismatch between errno 34 and code ENOENT

Question

So if I run this simple call in node.js v0.6.7 on OS X 10.6.8 with a bogus path, I get an error, as expected.

var fs = require("fs");
fs.stat("/tmp/foo", function(error, stat) {
    return console.log(error);
});

It prints this output:

{ [Error: ENOENT, no such file or directory '/tmp/foo'] errno: 34, code: 'ENOENT', path: '/tmp/foo' }

My question is, according to /usr/include/sys/errno.h on my system, ENOENT should have code 2, so why is this error saying errno 34 (ERANGE in errno.h), but pairing it with the error message from ENOENT?

Answer 1

node.js translates system errnos to internal "errnos" (see deps/uv/include/uv.h and uv_translate_sys_error in deps/uv/src/unix/error.c or deps/uv/src/win/error.c for a mapping) as to achieve a common representation for error-conditions under Windows and Unix.

34 is the node.js-errno for ENOENT, so everything is alright.

Answer 2

It seems that node.js changed the errno with 0.12.0. ENOENT is -2now.

So it is probably better to check for code === 'ENOENT'