feat(filterFilter): compare object with custom toString() to primitive

Closes #10464
Closes #10548

Author: Martin R. Hufsky

src/ng/filter/filter.js

@@ -54,6 +54,9 @@
  *   - `false|undefined`: A short hand for a function which will look for a substring match in case
  *     insensitive way.
  *
+ *     Primitive values are converted to strings. Objects are not compared against primitives,
+ *     unless they have a custom `toString` method (e.g. `Date` objects).
+ *
  * @example
    <example>
      <file name="index.html">
@@ -156,6 +159,10 @@ function filterFilter() {
   };
 }
 
+function hasCustomToString(obj) {
+  return isFunction(obj.toString) && obj.toString !== Object.prototype.toString;
+}
+
 // Helper functions for `filterFilter`
 function createPredicateFn(expression, comparator, matchAgainstAnyProp) {
   var shouldMatchPrimitives = isObject(expression) && ('$' in expression);
@@ -165,8 +172,8 @@ function createPredicateFn(expression, comparator, matchAgainstAnyProp) {
     comparator = equals;
   } else if (!isFunction(comparator)) {
     comparator = function(actual, expected) {
-      if (isObject(actual) || isObject(expected)) {
-        // Prevent an object to be considered equal to a string like `'[object'`
+      if (isObject(expected) || (isObject(actual) && !hasCustomToString(actual))) {
+        // Should not compare primitives against objects, unless they have custom `toString` method
         return false;
       }
 

test/ng/filter/filterSpec.js

@@ -472,6 +472,29 @@ describe('Filter: filter', function() {
     });
 
 
+    it('should consider custom `toString()` in non-strict comparison', function() {
+      var obj = new Date(1970, 0);
+      var items = [{test: obj}];
+      expect(filter(items, '1970').length).toBe(1);
+      expect(filter(items, 1970).length).toBe(1);
+
+      obj = {};
+      obj.toString = function() { return 'custom'; };
+      items = [{test: obj}];
+      expect(filter(items, 'custom').length).toBe(1);
+    });
+
+
+    it('should not throw on missing `toString()` in non-strict comparison', function() {
+      var obj = Object.create(null);
+      var items = [{test: obj}];
+      expect(function() {
+        filter(items, 'foo');
+      }).not.toThrow();
+      expect(filter(items, 'foo').length).toBe(0);
+    });
+
+
     it('as equality when true', function() {
       var items = ['misko', 'adam', 'adamson'];
       var expr = 'adam';