From b1c8fa39d6703d42f234a0082a478e4b0925b81e Mon Sep 17 00:00:00 2001
From: Liam DeBeasi <liamdebeasi@users.noreply.github.com>
Date: Mon, 26 Aug 2019 11:33:11 -0400
Subject: [PATCH] fix(swipe-back): account for negative step values (#19188)

fixes #19181
---
 core/src/utils/gesture/swipe-back.ts | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/core/src/utils/gesture/swipe-back.ts b/core/src/utils/gesture/swipe-back.ts
index 5c7a96afd6..3ac10df3a3 100644
--- a/core/src/utils/gesture/swipe-back.ts
+++ b/core/src/utils/gesture/swipe-back.ts
@@ -37,7 +37,13 @@ export const createSwipeBackGesture = (
       realDur = Math.min(dur, 540);
     }
 
-    onEndHandler(shouldComplete, stepValue, realDur);
+    /**
+     * TODO: stepValue can sometimes return a negative
+     * value, but you can't have a negative time value
+     * for the cubic bezier curve (at least with web animations)
+     * Not sure if the negative step value is an error or not
+     */
+    onEndHandler(shouldComplete, (stepValue <= 0) ? 0.01 : stepValue, realDur);
   };
 
   return createGesture({