fix: validate fd in JS land + add test

Author: vladfrangu

lib/internal/util.js

@@ -9,6 +9,7 @@ const {
   ErrorCaptureStackTrace,
   FunctionPrototypeCall,
   FunctionPrototypeSymbolHasInstance,
+  NumberIsInteger,
   NumberParseInt,
   ObjectDefineProperties,
   ObjectDefineProperty,
@@ -901,6 +902,10 @@ const handleTypes = ['TCP', 'TTY', 'UDP', 'FILE', 'PIPE', 'UNKNOWN'];
 handleTypes[-1] = 'INVALID';
 
 function guessHandleType(fd) {
+  if (!NumberIsInteger(fd)) {
+    return 'INVALID';
+  }
+
   const type = _guessHandleType(fd);
   return handleTypes[type];
 }

test/pseudo-tty/test-os-guessHandleType.js

@@ -0,0 +1,15 @@
+'use strict';
+
+require('../common');
+const { strictEqual } = require('assert');
+const { guessHandleType } = require('os');
+
+strictEqual(guessHandleType(0), 'TTY', 'stdin reported to not be a tty, but it is');
+strictEqual(guessHandleType(1), 'TTY', 'stdout reported to not be a tty, but it is');
+strictEqual(guessHandleType(2), 'TTY', 'stderr reported to not be a tty, but it is');
+
+strictEqual(guessHandleType(-1), 'INVALID', '-1 reported to be a tty, but it is not');
+strictEqual(guessHandleType(55555), 'UNKNOWN', '55555 reported to be a tty, but it is not');
+strictEqual(guessHandleType(2 ** 31), 'INVALID', '2^31 reported to be a tty, but it is not');
+strictEqual(guessHandleType(1.1), 'INVALID', '1.1 reported to be a tty, but it is not');
+strictEqual(guessHandleType('1'), 'INVALID', '\'1\' reported to be a tty, but it is not');