fs: accept all valid utf8 values in fast paths

Signed-off-by: Hamid Reza Ghavami <hamidr.ghavami@gmail.com>

Author: hamidrezaghavami

lib/fs.js

@@ -57,6 +57,13 @@ const {
   O_SYMLINK,
 } = constants;
 
+function isUtf8Encoding(encoding) {
+  return encoding === 'utf8' ||
+         encoding === 'utf-8' ||
+         encoding === 'UTF8' ||
+         encoding === 'UTF-8';
+}
+
 const pathModule = require('path');
 const { isArrayBufferView } = require('internal/util/types');
 
@@ -611,13 +618,18 @@ function readFileSync(path, options) {
   validateReadFileBufferOptions(options);
   const hasUserBuffer = options.buffer !== undefined;
 
+<<<<<<< HEAD
   if ((options.encoding === 'utf8' || options.encoding === 'utf-8') &&
       !hasUserBuffer) {
     if (isInt32(path)) {
       // V8 does not report -0 as an int32, so it would reach the binding as a
       // path instead of a file descriptor.
       path |= 0;
     } else {
+=======
+  if (isUtf8Encoding(options.encoding) && !hasUserBuffer) {
+    if (!isInt32(path)) {
+>>>>>>> fccaa919c21 (fs: accept all valid utf8 values in fast paths)
       path = getValidatedPath(path);
     }
     return binding.readFileUtf8(path, stringToFlags(options.flag));
@@ -3015,12 +3027,17 @@ function writeFileSync(path, data, options) {
   const flag = options.flag || 'w';
 
   // C++ fast path for string data and UTF8 encoding
+<<<<<<< HEAD
   if (typeof data === 'string' && (options.encoding === 'utf8' || options.encoding === 'utf-8')) {
     if (isInt32(path)) {
       // V8 does not report -0 as an int32, so it would reach the binding as a
       // path instead of a file descriptor.
       path |= 0;
     } else {
+=======
+  if (typeof data === 'string' && isUtf8Encoding(options.encoding)) {
+    if (!isInt32(path)) {
+>>>>>>> fccaa919c21 (fs: accept all valid utf8 values in fast paths)
       path = getValidatedPath(path);
     }
 
@@ -3320,7 +3337,7 @@ if (isWindows) {
 }
 
 function encodeRealpathResult(result, options) {
-  if (!options || !options.encoding || options.encoding === 'utf8')
+  if (!options || !options.encoding || isUtf8Encoding(options.encoding))
     return result;
   const asBuffer = Buffer.from(result);
   if (options.encoding === 'buffer') {