Implements matches with tests #12

Author: serkanyersen

src/underscore.py

@@ -1276,6 +1276,24 @@ def property(self):
         """
         return self._wrap(lambda obj, *args: obj[self.obj])
 
+    def matches(self):
+        """
+        Returns a predicate for checking whether an object has a given
+        set of `key:value` pairs.
+        """
+        def ret(obj, *args):
+            if self.obj is obj:
+                return True  # avoid comparing an object to itself.
+
+            for key in self.obj:
+                if self.obj[key] != obj[key]:
+                    return False
+
+            return True
+
+        return self._wrap(ret)
+
+
     def times(self, func, *args):
         """ Run a function **n** times.
         """

tests/test_objects.py

@@ -132,6 +132,13 @@ def test_invert(self):
         self.assertEqual(set(r), set('Larry Moe Curly'), 'can invert an object')
         self.assertEqual(_.invert(_.invert(obj)), obj, "two inverts gets you back where you started")
 
+    def test_matches(self):
+        moe = {"name": 'Moe Howard', "hair": True};
+        curly = {"name": 'Curly Howard', "hair": False};
+        stooges = [moe, curly]
+        self.assertTrue(_.find(stooges, _.matches({"hair": False})) == curly, "returns a predicate that can be used by finding functions.")
+        self.assertTrue(_.find(stooges, _.matches(moe)) == moe, "can be used to locate an object exists in a collection.")
+
 if __name__ == "__main__":
     print ("run these tests by executing `python -m unittest discover` in unittests folder")
     unittest.main()