fix(UrlMatcher): Array types: Pass empty arrays through in handler

fix(UrlMatcher): Fix broken pre-replace logic
Closes angular-ui#2222

src/urlMatcherFactory.js

@@ -261,7 +261,7 @@ UrlMatcher.prototype.exec = function (path, searchParams) {
     var param = this.params[paramName];
     var paramVal = m[i+1];
     // if the param value matches a pre-replace pair, replace the value before decoding.
-    for (j = 0; j < param.replace; j++) {
+    for (j = 0; j < param.replace.length; j++) {
       if (param.replace[j].from === paramVal) paramVal = param.replace[j].to;
     }
     if (paramVal && param.array === true) paramVal = decodePathArray(paramVal);
@@ -368,6 +368,7 @@ UrlMatcher.prototype.format = function (values) {
     } else {
       if (encoded == null || (isDefaultValue && squash !== false)) continue;
       if (!isArray(encoded)) encoded = [ encoded ];
+      if (encoded.length === 0) continue;
       encoded = map(encoded, encodeURIComponent).join('&' + name + '=');
       result += (search ? '&' : '?') + (name + '=' + encoded);
       search = true;
@@ -532,6 +533,7 @@ Type.prototype.$asArray = function(mode, isSearch) {
     // Wraps type (.is/.encode/.decode) functions to operate on each value of an array
     function arrayHandler(callback, allTruthyMode) {
       return function handleArray(val) {
+        if (isArray(val) && val.length === 0) return val;
         val = arrayWrap(val);
         var result = map(val, callback);
         if (allTruthyMode === true)

test/urlMatcherFactorySpec.js

@@ -272,6 +272,8 @@ describe("UrlMatcher", function () {
       expect(m.exec($location.path(), $location.search())).toEqual( { param1: undefined } );
       $location.url("/foo?param1=bar");
       expect(m.exec($location.path(), $location.search())).toEqual( { param1: 'bar' } ); // auto unwrap
+      $location.url("/foo?param1=");
+      expect(m.exec($location.path(), $location.search())).toEqual( { param1: undefined } );
       $location.url("/foo?param1=bar&param1=baz");
       if (angular.isArray($location.search())) // conditional for angular 1.0.8
         expect(m.exec($location.path(), $location.search())).toEqual( { param1: ['bar', 'baz'] } );
@@ -334,6 +336,29 @@ describe("UrlMatcher", function () {
       expect(m.format({ "param1[]": ['bar', 'baz'] })).toBe("/foo?param1[]=bar&param1[]=baz");
     }));
 
+    // Test for issue #2222
+    it("should return default value, if query param is missing.", inject(function($location) {
+      var m = new UrlMatcher('/state?param1&param2&param3&param5', {
+        params: {
+          param1 : 'value1',
+          param2 : {array: true, value: ['value2']},
+          param3 : {array: true, value: []},
+          param5 : {array: true, value: function() {return [];}}
+        }
+      });
+
+      var parsed = m.exec("/state");
+      var expected = {
+        "param1": 'value1',
+        "param2": ['value2'],
+        "param3": [],
+        "param5": []
+      };
+
+      expect(parsed).toEqualData(expected)
+      expect(m.params.$$values(parsed)).toEqualData(expected);
+    }));
+
     it("should not be wrapped by ui-router into an array if array: false", inject(function($location) {
       var m = new UrlMatcher('/foo?param1', { params: { param1: { array: false } } });