fs: use a default callback for fs.close()

jasnell · danielleadams · commit 655d19638a19 · 2021-02-16T09:12:41.000-05:00
The `fs.close()` function requires a callback. Most often the only thing that callback does is check and rethrow the error if one occurs. To eliminate common boilerplate, make the callback optional with a default that checks and rethrows the error as an uncaught exception. Signed-off-by: James M Snell <jasnell@gmail.com> PR-URL: #37174 Reviewed-By: Juan José Arboleda <soyjuanarbol@gmail.com> Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com> Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Darshan Sen <raisinten@gmail.com> Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com> Reviewed-By: Zijian Liu <lxxyxzj@gmail.com> Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
diff --git a/doc/api/fs.md b/doc/api/fs.md
@@ -1608,10 +1608,13 @@ This is the synchronous version of [`fs.chown()`][].
 
 See also: chown(2).
 
-## `fs.close(fd, callback)`
+## `fs.close(fd[, callback])`
 <!-- YAML
 added: v0.0.2
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/37174
+    description: A default callback is now used if one is not provided.
   - version: v10.0.0
     pr-url: https://github.com/nodejs/node/pull/12562
     description: The `callback` parameter is no longer optional. Not passing
@@ -1632,6 +1635,9 @@ to the completion callback.
 Calling `fs.close()` on any file descriptor (`fd`) that is currently in use
 through any other `fs` operation may lead to undefined behavior.
 
+If the `callback` argument is omitted, a default callback function that rethrows
+any error as an uncaught exception will be used.
+
 ## `fs.closeSync(fd)`
 <!-- YAML
 added: v0.1.21
diff --git a/lib/fs.js b/lib/fs.js
@@ -438,9 +438,14 @@ function readFileSync(path, options) {
   return buffer;
 }
 
-function close(fd, callback) {
+function defaultCloseCallback(err) {
+  if (err != null) throw err;
+}
+
+function close(fd, callback = defaultCloseCallback) {
   validateInt32(fd, 'fd', 0);
-  callback = makeCallback(callback);
+  if (callback !== defaultCloseCallback)
+    callback = makeCallback(callback);
 
   const req = new FSReqCallback();
   req.oncomplete = callback;
