buffer: improve .from() error details

This makes sure the original input is passed to the error in case no matching inputs are found. Instead of passing along all values, only valid or possibliy valid values are passed through. That way invalid values end up in the error case with the original input. PR-URL: #29675 Reviewed-By: Rich Trott <[email protected]>
nodejs · Jan 3, 2020 · 4df3652 · 4df3652
1 parent f570de8
commit 4df3652
Showing 1 changed file with 9 additions and 5 deletions.
diff --git a/lib/buffer.js b/lib/buffer.js
@@ -291,17 +291,21 @@ Buffer.from = function from(value, encodingOrOffset, length) {
       return fromArrayBuffer(value, encodingOrOffset, length);
 
     const valueOf = value.valueOf && value.valueOf();
-    if (valueOf !== null && valueOf !== undefined && valueOf !== value)
-      return Buffer.from(valueOf, encodingOrOffset, length);
+    if (valueOf != null &&
+        valueOf !== value &&
+        (typeof valueOf === 'string' || typeof valueOf === 'object')) {
+      return from(valueOf, encodingOrOffset, length);
+    }
 
     const b = fromObject(value);
     if (b)
       return b;
 
     if (typeof value[SymbolToPrimitive] === 'function') {
-      return Buffer.from(value[SymbolToPrimitive]('string'),
-                         encodingOrOffset,
-                         length);
+      const primitive = value[SymbolToPrimitive]('string');
+      if (typeof primitive === 'string') {
+        return fromString(primitive, encodingOrOffset);
+      }
     }
   }