make isPromise support null as a parameter

mochajs · Oct 15, 2018 · f6c4ecf · f6c4ecf
1 parent 01171b1
commit f6c4ecf
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/lib/utils.js b/lib/utils.js
@@ -660,7 +660,7 @@ exports.stackTraceFilter = function() {
  * @returns {boolean} Whether or not `value` is a Promise
  */
 exports.isPromise = function isPromise(value) {
-  return typeof value === 'object' && typeof value.then === 'function';
+  return typeof value === 'object' && value && typeof value.then === 'function';
 };
 
 /**