add basic uv-errmap test

test/parallel/test-uv-errmap.js

@@ -0,0 +1,24 @@
+// Flags: --expose-internals
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const {
+  getSystemErrorMap,
+  _errnoException
+} = require('util');
+
+const { internalBinding } = require('internal/test/binding');
+const uv = internalBinding('uv');
+const uvKeys = Object.keys(uv);
+
+const errMap = getSystemErrorMap();
+
+uvKeys.forEach((key) => {
+  if (!key.startsWith('UV_'))
+    return;
+
+  const err = _errnoException(uv[key]);
+  const name = uv.errname(uv[key]);
+  assert.strictEqual(errMap.get(err.errno)[0], name);
+});