fs: adjust default `length` for `fs.readSync` and fsPromises/`read`

Makes default length reasonable when nonzero offset is set.

PR-URL: https://github.com/nodejs/node/pull/42128
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

1 files changed, 9 insertions, 5 deletions

diff --git a/lib/fs.js b/lib/fs.js
index b8a5cefa1b..611eaaa90c 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -604,7 +604,7 @@ function read(fd, buffer, offset, length, position, callback) {
 
   if (arguments.length <= 3) {
     // Assume fs.read(fd, options, callback)
-    let options = {};
+    let options = ObjectCreate(null);
     if (arguments.length < 3) {
       // This is fs.read(fd, callback)
       // buffer will be the callback
@@ -621,7 +621,7 @@ function read(fd, buffer, offset, length, position, callback) {
       buffer = Buffer.alloc(16384),
       offset = 0,
       length = buffer.byteLength - offset,
-      position
+      position = null
     } = options);
   }
 
@@ -686,10 +686,14 @@ function readSync(fd, buffer, offset, length, position) {
   validateBuffer(buffer);
 
   if (arguments.length <= 3) {
-    // Assume fs.read(fd, buffer, options)
-    const options = offset || {};
+    // Assume fs.readSync(fd, buffer, options)
+    const options = offset || ObjectCreate(null);
 
-    ({ offset = 0, length = buffer.byteLength, position } = options);
+    ({
+      offset = 0,
+      length = buffer.byteLength - offset,
+      position = null
+    } = options);
   }
 
   if (offset == null) {