Test that ENOENT errors are ENOENTS

This is a test that would have caught the regression in stat uid
handling, because any call to an async function should not throw, and
any call to a sync function in these cases should throw the expected
ENOENT error.

Author: isaacs

test/enoent.js

@@ -0,0 +1,46 @@
+// this test makes sure that various things get enoent, instead of
+// some other kind of throw.
+
+var t = require('tap')
+var g = require('../')
+var file = 'this file does not exist even a little bit'
+var methods = [
+  ['open', 'r'],
+  ['readFile'],
+  ['stat'],
+  ['lstat'],
+  ['utimes', new Date(), new Date()],
+  ['readdir']
+]
+
+// any version > v6 can do readdir(path, options, cb)
+if (process.version.match(/^v([6-9]|[1-9][0-9])\./)) {
+  methods.push(['readdir', {}])
+}
+
+t.plan(methods.length)
+methods.forEach(function (method) {
+  t.test(method[0], runTest(method))
+})
+
+function runTest (args) { return function (t) {
+  var method = args.shift()
+  args.unshift(file)
+  var methodSync = method + 'Sync'
+  t.isa(g[methodSync], 'function')
+  t.throws(function () {
+    g[methodSync].apply(g, args)
+  }, { code: 'ENOENT' })
+  // add the callback
+  args.push(verify(t))
+  t.isa(g[method], 'function')
+  t.doesNotThrow(function () {
+    g[method].apply(g, args)
+  })
+}}
+
+function verify (t) { return function (er) {
+  t.isa(er, Error)
+  t.equal(er.code, 'ENOENT')
+  t.end()
+}}