fix suggestions

ex.txt

@@ -0,0 +1 @@
+Hello world

index.mjs

@@ -0,0 +1,22 @@
+import fs from "fs/promises";
+
+async function test() {
+  let path = './ex.txt';
+
+  let buf = Buffer.alloc(4);
+  let handle;
+  try {
+    handle = await fs.open(path);
+    {
+      let buf = Buffer.alloc(4);
+      let { bytesRead, buffer } = await handle.read(buf);
+    //   let { bytesRead, buffer } = await handle.read(buf, {}); // It is behavior I would expect.
+      console.log(bytesRead);
+      console.log(buffer);
+      console.log(buf);
+    }
+  } finally {
+    await handle?.close();
+  }
+}
+test();

lib/internal/fs/promises.js

@@ -670,7 +670,7 @@ async function read(handle, bufferOrParams, offset, length, position) {
     validateInteger(offset, 'offset', 0);
   }
 
-  length = length ?? buffer.byteLength - offset;
+  length ??= buffer.byteLength - offset;
 
   if (length === 0)
     return { __proto__: null, bytesRead: length, buffer };