From 27cb9b60a3399955c8df1405090b81d22be4315e Mon Sep 17 00:00:00 2001
From: Nicholas Jamieson <nicholas@cartant.com>
Date: Thu, 17 May 2018 18:41:10 +1000
Subject: [PATCH] fix(TestScheduler): restore run changes upon error

---
 src/internal/testing/TestScheduler.ts | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/src/internal/testing/TestScheduler.ts b/src/internal/testing/TestScheduler.ts
index 329b3f3319..60474b3078 100644
--- a/src/internal/testing/TestScheduler.ts
+++ b/src/internal/testing/TestScheduler.ts
@@ -378,14 +378,15 @@ export class TestScheduler extends VirtualTimeScheduler {
       expectObservable: this.expectObservable.bind(this),
       expectSubscriptions: this.expectSubscriptions.bind(this),
     };
-    const ret = callback(helpers);
-    this.flush();
-
-    TestScheduler.frameTimeFactor = prevFrameTimeFactor;
-    this.maxFrames = prevMaxFrames;
-    this.runMode = false;
-    AsyncScheduler.delegate = undefined;
-
-    return ret;
+    try {
+      const ret = callback(helpers);
+      this.flush();
+      return ret;
+    } finally {
+      TestScheduler.frameTimeFactor = prevFrameTimeFactor;
+      this.maxFrames = prevMaxFrames;
+      this.runMode = false;
+      AsyncScheduler.delegate = undefined;
+    }
   }
 }