fs: silently swallow error if cb is omitted

Commit a804347 makes fs function rethrow errors when the callback is omitted. While the right thing to do, it's a change from the old v0.8 behavior where such errors were silently ignored. To give users time to upgrade, temporarily disable that and replace it with a function that warns once about the deprecated behavior. Fixes #5005.
nodejs · Mar 13, 2013 · a9f277e · a9f277e
1 parent 110cacd
commit a9f277e
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Showing 2 changed files with 44 additions and 2 deletions.
diff --git a/lib/fs.js b/lib/fs.js
@@ -77,16 +77,53 @@ function rethrow() {
   };
 }
 
+// TODO Replace with rethrow() in v0.12.
+var swallow = null;
+
 function maybeCallback(cb) {
-  return typeof cb === 'function' ? cb : rethrow();
+  if (typeof cb === 'function') {
+    return cb;
+  }
+
+  if (typeof swallow !== 'function') {
+    var backtrace = null;
+
+    if (process.noDeprecation !== true) {
+      // Warn once and give the user a stack trace that points to the callee.
+      var errmsg = 'Silent fs error swallowing is deprecated and will be ' +
+                   'removed in v0.12';
+      if (process.throwDeprecation !== true &&
+          process.traceDeprecation !== true) {
+        errmsg += '\n' +
+                  'Use --trace-deprecation or --throw-deprecation to get ' +
+                  'a stack trace.';
+      }
+      backtrace = new Error(errmsg);
+    }
+
+    swallow = function() {
+      if (backtrace === null) return;
+      var err = backtrace;
+      backtrace = null;
+      if (process.throwDeprecation) {
+        throw err;
+      }
+      console.error(err.message);
+      if (process.traceDeprecation) {
+        console.error(err.stack);
+      }
+    };
+  }
+
+  return swallow;
 }
 
 // Ensure that callbacks run in the global context. Only use this function
 // for callbacks that are passed to the binding layer, callbacks that are
 // invoked from JS already run in the proper scope.
 function makeCallback(cb) {
   if (typeof cb !== 'function') {
-    return rethrow();
+    return maybeCallback(null);
   }
 
   return function() {

diff --git a/test/simple/test-fs-readfile-error.js b/test/simple/test-fs-readfile-error.js
@@ -24,6 +24,11 @@ var assert = require('assert');
 var exec = require('child_process').exec;
 var path = require('path');
 
+if (process.versions.node.indexOf('0.10') === 0) {
+  console.log('Skipping test, fs debug stack traces are disabled in v0.10.');
+  return;
+}
+
 var callbacks = 0;
 
 function test(env, cb) {