util: handle symbols properly in format()

Currently, if util.format() is called with a string as its first argument, and a Symbol as one of the subsequent arguments, an exception is thrown due to an attempted implicit string conversion. This commit causes Symbols to be explicitly converted. Fixes: #927 PR-URL: #931 Reviewed-By: Domenic Denicola <[email protected]>
nodejs · Feb 24, 2015 · ed3b057 · ed3b057
1 parent da730c7
commit ed3b057
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Showing 2 changed files with 11 additions and 1 deletion.
diff --git a/lib/util.js b/lib/util.js
@@ -30,7 +30,7 @@ exports.format = function(f) {
     }
   });
   for (var x = args[i]; i < len; x = args[++i]) {
-    if (x === null || typeof x !== 'object') {
+    if (x === null || (typeof x !== 'object' && typeof x !== 'symbol')) {
       str += ' ' + x;
     } else {
       str += ' ' + inspect(x);

diff --git a/test/parallel/test-util-format.js b/test/parallel/test-util-format.js
@@ -1,6 +1,7 @@
 var common = require('../common');
 var assert = require('assert');
 var util = require('util');
+var symbol = Symbol('foo');
 
 assert.equal(util.format(), '');
 assert.equal(util.format(''), '');
@@ -14,6 +15,15 @@ assert.equal(util.format('test'), 'test');
 // CHECKME this is for console.log() compatibility - but is it *right*?
 assert.equal(util.format('foo', 'bar', 'baz'), 'foo bar baz');
 
+// ES6 Symbol handling
+assert.equal(util.format(symbol), 'Symbol(foo)');
+assert.equal(util.format('foo', symbol), 'foo Symbol(foo)');
+assert.equal(util.format('%s', symbol), 'Symbol(foo)');
+assert.equal(util.format('%j', symbol), 'undefined');
+assert.throws(function() {
+  util.format('%d', symbol);
+}, TypeError);
+
 assert.equal(util.format('%d', 42.0), '42');
 assert.equal(util.format('%d', 42), '42');
 assert.equal(util.format('%s', 42), '42');