$state.href() returns null instead of throwing.

Author: nateabele

src/state.js

@@ -269,12 +269,8 @@ function $StateProvider(   $urlRouterProvider,   $urlMatcherFactory) {
     $state.href = function (stateOrName, params, options) {
       options = extend({ lossy: true }, options || {});
       var state = findState(stateOrName);
-      var nav = options.lossy ? state.navigable : state;
-
-      if (!nav || !nav.url) throw new Error("State '" + state + "' " + (
-        options.lossy ? "does not have a URL or navigable parent" : "is not navigable"
-      ));
-      return nav.url.format(normalize(state.params, params || {}));
+      var nav = (state && options.lossy) ? state.navigable : state;
+      return (nav && nav.url) ? nav.url.format(normalize(state.params, params || {})) : null;
     };
 
     function resolveState(state, params, paramsAreFiltered, inherited, dst) {

src/stateDirectives.js

@@ -18,11 +18,13 @@ function $StateRefDirective($state) {
         if (newVal) params = newVal;
         if (!nav) return;
 
-        try {
-          element[0][attr] = $state.href(ref.state, params, { lossy: true });
-        } catch (e) {
+        var newHref = $state.href(ref.state, params, { lossy: true });
+
+        if (!newHref) {
           nav = false;
+          return false;
         }
+        element[0][attr] = newHref;
       };
 
       if (ref.paramExpr) {

test/stateSpec.js

@@ -256,12 +256,8 @@ describe('state', function () {
 
   describe('.href()', function () {
     it('aborts on un-navigable states', inject(function ($state) {
-      expect(function() { $state.href("A"); }).toThrow(
-        "State 'A' does not have a URL or navigable parent"
-      );
-      expect(function() { $state.href("about.sidebar", null, { lossy: false }); }).toThrow(
-        "State 'about.sidebar' is not navigable"
-      );
+      expect($state.href("A")).toBeNull();
+      expect($state.href("about.sidebar", null, { lossy: false })).toBeNull();
     }));
 
     it('generates a parent state URL when lossy is true', inject(function ($state) {