From 88052bf9fda3545416808ff61b3bce4ab40f1ed8 Mon Sep 17 00:00:00 2001
From: Chris Thielen <github@sandgnat.com>
Date: Thu, 8 Sep 2016 23:07:08 -0500
Subject: [PATCH] feat(redirect): Error after 20+ redirected transitions

---
 src/transition/transition.ts  |  5 +++++
 test/core/stateServiceSpec.ts | 15 +++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/src/transition/transition.ts b/src/transition/transition.ts
index a142c6683..6ba36c58c 100644
--- a/src/transition/transition.ts
+++ b/src/transition/transition.ts
@@ -551,6 +551,11 @@ export class Transition implements IHookRegistry {
   error() {
     let state: State = this.$to();
 
+    let redirects = 0, trans: Transition = this;
+    while((trans = trans.redirectedFrom()) != null) {
+      if (++redirects > 20) return `Too many Transition redirects (20+)`;
+    }
+
     if (state.self.abstract)
       return `Cannot transition to abstract state '${state.name}'`;
     if (!Param.validates(state.parameters(), this.params()))
diff --git a/test/core/stateServiceSpec.ts b/test/core/stateServiceSpec.ts
index 112af09f1..a219acdee 100644
--- a/test/core/stateServiceSpec.ts
+++ b/test/core/stateServiceSpec.ts
@@ -62,6 +62,21 @@ describe('stateService', function () {
       .then(done, done);
     }));
 
+    it('should error after 20+ redirects', (done) => {
+      let errors = [];
+      $transitions.onEnter({ entering: "D" }, trans => trans.router.stateService.target('D'));
+      $transitions.onError({}, trans => { errors.push(trans.error()) });
+
+      $state.defaultErrorHandler(function() {});
+
+      $state.go("D").catch(err => {
+        expect(errors.length).toBe(21);
+        expect(err.message).toContain('Too many Transition redirects');
+        done();
+      });
+    })
+
+
     it("should not update the URL in response to synchronizing URL", ((done) => {
       $loc.setUrl('/a/b/c');
       spyOn($loc, 'setUrl').and.callThrough();