merged _.match

test/collections.js

@@ -266,16 +266,8 @@
     result = _.where(list, {b: 2});
     equal(result.length, 2);
     equal(result[0].a, 1);
-
-    result = _.where(list, {a: 1}, true);
-    equal(result.b, 2, 'Only get the first object matched.')
-    result = _.where(list, {a: 1}, false);
-    equal(result.length, 3);
-
     result = _.where(list, {});
     equal(result.length, list.length);
-    result = _.where(list, {}, true);
-    equal(result, list[0]);
   });
 
   test('findWhere', function() {

test/objects.js

@@ -578,15 +578,23 @@
     ok(returned == 6 && intercepted == 6, 'can use tapped objects in a chain');
   });
 
-  test('has', function () {
-     var obj = {foo: 'bar', func: function () {} };
-     ok (_.has(obj, 'foo'), 'has() checks that the object has a property.');
-     ok (_.has(obj, 'baz') == false, "has() returns false if the object doesn't have the property.");
-     ok (_.has(obj, 'func'), 'has() works for functions too.');
-     obj.hasOwnProperty = null;
-     ok (_.has(obj, 'foo'), 'has() works even when the hasOwnProperty method is deleted.');
-     var child = {};
-     child.prototype = obj;
-     ok (_.has(child, 'foo') == false, 'has() does not check the prototype chain for a property.')
+  test("has", function () {
+    var obj = {foo: "bar", func: function () {} };
+    ok(_.has(obj, "foo"), "has() checks that the object has a property.");
+    ok(_.has(obj, "baz") == false, "has() returns false if the object doesn't have the property.");
+    ok(_.has(obj, "func"), "has() works for functions too.");
+    obj.hasOwnProperty = null;
+    ok(_.has(obj, "foo"), "has() works even when the hasOwnProperty method is deleted.");
+    var child = {};
+    child.prototype = obj;
+    ok(_.has(child, "foo") == false, "has() does not check the prototype chain for a property.")
   });
+
+  test("match", function() {
+    var moe     = {name: 'Moe Howard',   hair: true},
+        curly   = {name: 'Curly Howard', hair: false},
+        stooges = [moe, curly];
+    ok(_.find(stooges, _.match({hair: false})) === curly, "returns a predicate that can be used by finding functions.")
+    ok(_.find(stooges, _.match(moe)) === moe, "can be used to locate an object exists in a collection.")
+  })
 })();

underscore.js

@@ -238,19 +238,14 @@
 
   // Convenience version of a common use case of `filter`: selecting only objects
   // containing specific `key:value` pairs.
-  _.where = function(obj, attrs, first) {
-    return _[first ? 'find' : 'filter'](obj, function(value) {
-      for (var key in attrs) {
-        if (attrs[key] !== value[key]) return false;
-      }
-      return true;
-    });
+  _.where = function(obj, attrs) {
+    return _.filter(obj, _.match(attrs));
   };
 
   // Convenience version of a common use case of `find`: getting the first object
   // containing specific `key:value` pairs.
   _.findWhere = function(obj, attrs) {
-    return _.where(obj, attrs, true);
+    return _.find(obj, _.match(attrs));
   };
 
   // Return the maximum element or (element-based computation).
@@ -1106,6 +1101,18 @@
     };
   };
 
+  // Returns a predicate for checking whether an object has a given set of `key:value` pairs.
+  _.match = function(attrs) {
+    return function(obj) {
+      if (obj === attrs) return true; //avoid comparing an object to itself.
+      for (var key in attrs) {
+        if (attrs[key] !== obj[key])
+          return false;
+      }
+      return true;
+    }
+  };
+
   // Run a function **n** times.
   _.times = function(n, iterator, context) {
     var accum = Array(Math.max(0, n));