From 8c2a57878b04d0bda67096b2cbc0f2736b8db27d Mon Sep 17 00:00:00 2001
From: adasilva <adasilva@grubhub.com>
Date: Wed, 14 Mar 2018 14:30:38 -0400
Subject: [PATCH] fix(service-worker): fix LruList bugs (#22769)

'remove' method not removing url from state.map
'accessed' method not removing 'previous' reference from existing  node when it becomes the head

Fixes #22218
Fixes #22768

PR Close #22769
---
 packages/service-worker/worker/src/data.ts | 25 ++++++----------------
 1 file changed, 6 insertions(+), 19 deletions(-)

diff --git a/packages/service-worker/worker/src/data.ts b/packages/service-worker/worker/src/data.ts
index 5608611888..e1d98f2951 100644
--- a/packages/service-worker/worker/src/data.ts
+++ b/packages/service-worker/worker/src/data.ts
@@ -99,25 +99,7 @@ class LruList {
     }
 
     const url = this.state.tail;
-
-    // Special case if this is the last node.
-    if (this.state.head === this.state.tail) {
-      // When removing the last node, both head and tail pointers become null.
-      this.state.head = null;
-      this.state.tail = null;
-    } else {
-      // Normal node removal. All that needs to be done is to clear the next pointer
-      // of the previous node and make it the new tail.
-      const block = this.state.map[url] !;
-      const previous = this.state.map[block.previous !] !;
-      this.state.tail = previous.url;
-      previous.next = block.next;
-    }
-
-    // In any case, this URL is no longer tracked, so remove it from the count and the
-    // map of tracked URLs.
-    delete this.state.map[url];
-    this.state.count--;
+    this.remove(url);
 
     // This URL has been successfully evicted.
     return url;
@@ -145,6 +127,8 @@ class LruList {
       const next = this.state.map[node.next !] !;
       next.previous = null;
       this.state.head = next.url;
+      node.next = null;
+      delete this.state.map[url];
       this.state.count--;
       return true;
     }
@@ -167,6 +151,9 @@ class LruList {
       this.state.tail = node.previous !;
     }
 
+    node.next = null;
+    node.previous = null;
+    delete this.state.map[url];
     // Count the removal.
     this.state.count--;