From e7f4dccfc3de2e3829ee09a5e9b439c9c52660f9 Mon Sep 17 00:00:00 2001
From: Fred Cox <mcfedr@gmail.com>
Date: Sat, 2 Feb 2019 16:23:16 +0200
Subject: [PATCH] Clear sequentialize cache when empty to remove chance of
 memory leaks (#26)

---
 spec/common/misc/sequentialize.spec.ts |  4 ++--
 src/misc/sequentialize.ts              | 17 ++++++++---------
 2 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/spec/common/misc/sequentialize.spec.ts b/spec/common/misc/sequentialize.spec.ts
index 8bb2701cb2..86e846b38e 100644
--- a/spec/common/misc/sequentialize.spec.ts
+++ b/spec/common/misc/sequentialize.spec.ts
@@ -120,7 +120,7 @@ class Foo {
     calls = 0;
 
     @sequentialize((args) => 'bar' + args[0])
-    bar(a: any) {
+    bar(a: number) {
         this.calls++;
         return new Promise((res) => {
             setTimeout(() => {
@@ -130,7 +130,7 @@ class Foo {
     }
 
     @sequentialize((args) => 'baz' + args[0])
-    baz(a: any) {
+    baz(a: number) {
         this.calls++;
         return new Promise((res) => {
             setTimeout(() => {
diff --git a/src/misc/sequentialize.ts b/src/misc/sequentialize.ts
index b9501a8ad2..221b9da23b 100644
--- a/src/misc/sequentialize.ts
+++ b/src/misc/sequentialize.ts
@@ -6,7 +6,6 @@
  *
  * Results are not cached, once the promise has returned, the next call will result in a fresh call
  *
- * WARNING: The decorator's scope is singleton, so using it on transient objects can lead to memory leaks.
  * Read more at https://github.com/bitwarden/jslib/pull/7
  */
 export function sequentialize(cacheKey: (args: any[]) => string) {
@@ -26,20 +25,20 @@ export function sequentialize(cacheKey: (args: any[]) => string) {
 
         return {
             value: function(...args: any[]) {
-                const argsCacheKey = cacheKey(args);
                 const cache = getCache(this);
+                const argsCacheKey = cacheKey(args);
                 let response = cache.get(argsCacheKey);
                 if (response != null) {
                     return response;
                 }
 
-                response = originalMethod.apply(this, args).then((val: any) => {
-                    cache.delete(argsCacheKey);
-                    return val;
-                }).catch((err: any) => {
-                    cache.delete(argsCacheKey);
-                    throw err;
-                });
+                response = originalMethod.apply(this, args)
+                    .finally(() => {
+                        cache.delete(argsCacheKey);
+                        if (cache.size === 0) {
+                            caches.delete(this);
+                        }
+                    });
 
                 cache.set(argsCacheKey, response);
                 return response;