wallet-core: simplify/optimize async condition

1 files changed, 12 insertions, 12 deletions

diff --git a/packages/taler-wallet-core/src/util/promiseUtils.ts b/packages/taler-wallet-core/src/util/promiseUtils.ts
index d409686d9..23f1c06a5 100644
--- a/packages/taler-wallet-core/src/util/promiseUtils.ts
+++ b/packages/taler-wallet-core/src/util/promiseUtils.ts
@@ -23,6 +23,8 @@ export interface OpenedPromise<T> {
 /**
  * Get an unresolved promise together with its extracted resolve / reject
  * function.
+ *
+ * Recent ECMAScript proposals also call this a promise capability.
  */
 export function openPromise<T>(): OpenedPromise<T> {
   let resolve: ((x?: any) => void) | null = null;
@@ -39,22 +41,20 @@ export function openPromise<T>(): OpenedPromise<T> {
 }
 
 export class AsyncCondition {
-  private _waitPromise: Promise<void>;
-  private _resolveWaitPromise: (val: void) => void;
-  constructor() {
-    const op = openPromise<void>();
-    this._waitPromise = op.promise;
-    this._resolveWaitPromise = op.resolve;
-  }
+  private promCap?: OpenedPromise<void> = undefined;
+  constructor() {}
 
   wait(): Promise<void> {
-    return this._waitPromise;
+    if (!this.promCap) {
+      this.promCap = openPromise<void>();
+    }
+    return this.promCap.promise;
   }
 
   trigger(): void {
-    this._resolveWaitPromise();
-    const op = openPromise<void>();
-    this._waitPromise = op.promise;
-    this._resolveWaitPromise = op.resolve;
+    if (this.promCap) {
+      this.promCap.resolve();
+    }
+    this.promCap = undefined;
   }
 }