fix: date-time string validation to fail validating for date-only strings instead of throwing a TypeError

lib/compile/formats.js

@@ -90,6 +90,8 @@ function date(str) {
 
 
 function time(str, full) {
+  if (str === undefined) return false;
+
   var matches = str.match(TIME);
   if (!matches) return false;
 

spec/tests/rules/format.json

@@ -100,6 +100,22 @@
       }
     ]
   },
+  {
+    "description": "validation of date-time strings",
+    "schema": {"format": "date-time"},
+    "tests": [
+      {
+        "description": "a valid date-time string",
+        "data": "1963-06-19T12:13:14Z",
+        "valid": true
+      },
+      {
+        "description": "an invalid date-time string",
+        "data": "1963-06-19",
+        "valid": false
+      }
+    ]
+  },
   {
     "description": "validation of uuid strings",
     "schema": {"format": "uuid"},