feat: Allow ConditionalHandler to set the expected value

src/util/handlers/ConditionalHandler.ts

@@ -8,22 +8,27 @@ import { AsyncHandler } from './AsyncHandler';
  * After that all input will be rejected.
  * Once the value has been matched this behaviour will be cached,
  * so changing the value again afterwards will not enable this handler again.
+ *
+ * If `handleStorage` is set to `true`,
+ * this handler will set the value itself in the given storage after the source handler successfully resolved.
  */
 export class ConditionalHandler<TIn, TOut> extends AsyncHandler<TIn, TOut> {
   private readonly source: AsyncHandler<TIn, TOut>;
   private readonly storage: KeyValueStorage<string, unknown>;
   private readonly storageKey: string;
   private readonly storageValue: unknown;
+  private readonly handleStorage: boolean;
 
   private finished: boolean;
 
   public constructor(source: AsyncHandler<TIn, TOut>, storage: KeyValueStorage<string, unknown>, storageKey: string,
-    storageValue: unknown) {
+    storageValue: unknown, handleStorage = false) {
     super();
     this.source = source;
     this.storage = storage;
     this.storageKey = storageKey;
     this.storageValue = storageValue;
+    this.handleStorage = handleStorage;
 
     this.finished = false;
   }
@@ -35,11 +40,21 @@ export class ConditionalHandler<TIn, TOut> extends AsyncHandler<TIn, TOut> {
 
   public async handleSafe(input: TIn): Promise<TOut> {
     await this.checkCondition();
-    return this.source.handleSafe(input);
+    const result = await this.source.handleSafe(input);
+    if (this.handleStorage) {
+      await this.storage.set(this.storageKey, this.storageValue);
+      this.finished = true;
+    }
+    return result;
   }
 
   public async handle(input: TIn): Promise<TOut> {
-    return this.source.handle(input);
+    const result = await this.source.handle(input);
+    if (this.handleStorage) {
+      await this.storage.set(this.storageKey, this.storageValue);
+      this.finished = true;
+    }
+    return result;
   }
 
   /**