fix(router): prevent double navs

ionic/components/nav/nav-controller.ts

@@ -229,8 +229,7 @@ export class NavController extends Ion {
     }
 
     if (this.isTransitioning()) {
-      console.debug('nav controller actively transitioning');
-      return Promise.reject();
+      return Promise.reject('nav controller actively transitioning');
     }
 
     this.setTransitioning(true, 500);
@@ -301,12 +300,11 @@ export class NavController extends Ion {
    */
   pop(opts = {}) {
     if (!opts.animateFirst && !this.canGoBack()) {
-      return Promise.reject();
+      return Promise.reject('pop cannot go back');
     }
 
     if (this.isTransitioning()) {
-      console.debug('nav controller actively transitioning');
-      return Promise.reject();
+      return Promise.reject('nav controller actively transitioning';
     }
 
     this.setTransitioning(true, 500);
@@ -422,7 +420,7 @@ export class NavController extends Ion {
    */
   insert(index, componentType, params = {}, opts = {}) {
     if (!componentType || index < 0) {
-      return Promise.reject();
+      return Promise.reject('invalid insert');
     }
 
     // push it onto the end
@@ -464,7 +462,7 @@ export class NavController extends Ion {
    */
   remove(index, opts = {}) {
     if (index < 0 || index >= this._views.length) {
-      return Promise.reject("Index out of range");
+      return Promise.reject("index out of range");
     }
 
     let viewToRemove = this._views[index];

ionic/components/nav/nav-router.ts

@@ -51,7 +51,7 @@ export class NavRouter extends RouterOutlet {
 
     // prevent double navigations to the same view
     var lastView = this.nav.last();
-    if (lastView && lastView.componentType === componentType && lastView.params.data === nextInstruction.params) {
+    if (this.nav.isTransitioning() || lastView && lastView.componentType === componentType && lastView.params.data === nextInstruction.params) {
       return Promise.resolve();
     }
 

ionic/components/tabs/tab.ts

@@ -102,15 +102,14 @@ export class Tab extends NavController {
     } else if (this.parent.preloadTabs) {
       this._loadTimer = setTimeout(() => {
         if (!this._loaded) {
-          let opts = {
+          this.load({
             animate: false,
             preload: true,
             postLoad: (viewCtrl) => {
               let navbar = viewCtrl.getNavbar();
               navbar && navbar.setHidden(true);
             }
-          };
-          this.load(opts);
+          }, function(){});
         }
       }, 1000 * this.index);
     }

ionic/components/tabs/test/advanced/index.ts

@@ -33,7 +33,7 @@ class SignIn {
 
   push() {
     setTimeout(() => {
-      this.nav.setRoot(TabsPage, null, { animate: true });
+      this.nav.push(TabsPage);
     }, 1000);
   }
 }