#2629 Throw error when identifier is a non-string value

RELEASE-NOTES.md

@@ -11,6 +11,7 @@
 - **Segment* - `horizontal segments` in IE will no longer stretch to the natural width of child imgs #2550 [flexbug #1](https://github.com/philipwalton/flexbugs#1-minimum-content-sizing-of-flex-items-not-honored)
 - **Sticky** - Fixed `sticky` element that cannot fit in viewport not scrolling correctly when fixed to viewport #2605
 - **Form** - Fixed issue with `minLength[1]` validation not behaving same as `minLength > 2` #2636.
+- **Form** - Form fields will now error when a non-string identifier is used
 
 **Additional Bugs**
 - **Popup** - `wide` and `very wide` popup will now limit themselves to normal popup widths on mobile so that they still appear on screen.

src/definitions/behaviors/form.js

@@ -495,6 +495,9 @@ $.fn.form = function(parameters) {
 
           field: function(identifier) {
             module.verbose('Checking for existence of a field with identifier', identifier);
+            if(typeof identifier !== 'string') {
+              module.error(error.identifier, identifier);
+            }
             if( $field.filter('#' + identifier).length > 0 ) {
               return true;
             }
@@ -1017,9 +1020,10 @@ $.fn.form.settings = {
   },
 
   error: {
-    oldSyntax : 'Starting in 2.0 forms now only take a single settings object. Validation settings converted to new syntax automatically.',
-    noRule    : 'There is no rule matching the one you specified',
-    method    : 'The method you called is not defined.'
+    oldSyntax  : 'Starting in 2.0 forms now only take a single settings object. Validation settings converted to new syntax automatically.',
+    identifier : 'You must specify a string identifier for each field',
+    noRule     : 'There is no rule matching the one you specified',
+    method     : 'The method you called is not defined.'
   },
 
   templates: {