assert: use util.inspect() to create error messages

Currently, JSON.stringify() is used to create error messages on failed assertions. This causes an error when stringifying objects with circular references. This commit switches out JSON.stringify() for util.inspect(), which can handle circular references. PR-URL: #668 Reviewed-By: Julien Gilli <[email protected]> Reviewed-By: Bert Belder <[email protected]> Reviewed-By: Chris Dickinson <[email protected]>
nodejs · Jan 31, 2015 · 40e29dc · 40e29dc
1 parent bc2c85c
commit 40e29dc
Show file tree

Hide file tree

Showing 2 changed files with 20 additions and 28 deletions.
diff --git a/lib/assert.js b/lib/assert.js
@@ -58,19 +58,6 @@ assert.AssertionError = function AssertionError(options) {
 // assert.AssertionError instanceof Error
 util.inherits(assert.AssertionError, Error);
 
-function replacer(key, value) {
-  if (util.isUndefined(value)) {
-    return '' + value;
-  }
-  if (util.isNumber(value) && !isFinite(value)) {
-    return value.toString();
-  }
-  if (util.isFunction(value) || util.isRegExp(value)) {
-    return value.toString();
-  }
-  return value;
-}
-
 function truncate(s, n) {
   if (util.isString(s)) {
     return s.length < n ? s : s.slice(0, n);
@@ -80,9 +67,9 @@ function truncate(s, n) {
 }
 
 function getMessage(self) {
-  return truncate(JSON.stringify(self.actual, replacer), 128) + ' ' +
+  return truncate(util.inspect(self.actual), 128) + ' ' +
          self.operator + ' ' +
-         truncate(JSON.stringify(self.expected, replacer), 128);
+         truncate(util.inspect(self.expected), 128);
 }
 
 // At present only the three keys mentioned above are used and

diff --git a/test/parallel/test-assert.js b/test/parallel/test-assert.js
@@ -249,36 +249,41 @@ a.throws(makeBlock(a.deepEqual, args, []));
 assert.ok(gotError);
 
 
-// #217
+var circular = {y: 1};
+circular.x = circular;
+
 function testAssertionMessage(actual, expected) {
   try {
     assert.equal(actual, '');
   } catch (e) {
     assert.equal(e.toString(),
-        ['AssertionError:', expected, '==', '""'].join(' '));
+        ['AssertionError:', expected, '==', '\'\''].join(' '));
     assert.ok(e.generatedMessage, "Message not marked as generated");
   }
 }
-testAssertionMessage(undefined, '"undefined"');
+
+testAssertionMessage(undefined, 'undefined');
 testAssertionMessage(null, 'null');
 testAssertionMessage(true, 'true');
 testAssertionMessage(false, 'false');
 testAssertionMessage(0, '0');
 testAssertionMessage(100, '100');
-testAssertionMessage(NaN, '"NaN"');
-testAssertionMessage(Infinity, '"Infinity"');
-testAssertionMessage(-Infinity, '"-Infinity"');
+testAssertionMessage(NaN, 'NaN');
+testAssertionMessage(Infinity, 'Infinity');
+testAssertionMessage(-Infinity, '-Infinity');
 testAssertionMessage('', '""');
-testAssertionMessage('foo', '"foo"');
+testAssertionMessage('foo', '\'foo\'');
 testAssertionMessage([], '[]');
-testAssertionMessage([1, 2, 3], '[1,2,3]');
-testAssertionMessage(/a/, '"/a/"');
-testAssertionMessage(/abc/gim, '"/abc/gim"');
-testAssertionMessage(function f() {}, '"function f() {}"');
+testAssertionMessage([1, 2, 3], '[ 1, 2, 3 ]');
+testAssertionMessage(/a/, '/a/');
+testAssertionMessage(/abc/gim, '/abc/gim');
+testAssertionMessage(function f() {}, '[Function: f]');
+testAssertionMessage(function () {}, '[Function]');
 testAssertionMessage({}, '{}');
-testAssertionMessage({a: undefined, b: null}, '{"a":"undefined","b":null}');
+testAssertionMessage(circular, '{ y: 1, x: [Circular] }');
+testAssertionMessage({a: undefined, b: null}, '{ a: undefined, b: null }');
 testAssertionMessage({a: NaN, b: Infinity, c: -Infinity},
-    '{"a":"NaN","b":"Infinity","c":"-Infinity"}');
+    '{ a: NaN, b: Infinity, c: -Infinity }');
 
 // #2893
 try {