NapCatQQ source snapshot

packages/napcat-common/src/fall-back.ts

@@ -0,0 +1,42 @@
+type Handler<T> = () => T | Promise<T>;
+type Checker<T> = (result: T) => T | Promise<T>;
+
+export class Fallback<T> {
+  private handlers: Handler<T>[] = [];
+  private checker: Checker<T>;
+
+  constructor (checker?: Checker<T>) {
+    this.checker = checker || (async (result: T) => result);
+  }
+
+  add (handler: Handler<T>): this {
+    this.handlers.push(handler);
+    return this;
+  }
+
+  // 执行处理程序链
+  async run (): Promise<T> {
+    const errors: Error[] = [];
+    for (const handler of this.handlers) {
+      try {
+        const result = await handler();
+        const data = await this.checker(result);
+        if (data) {
+          return data;
+        }
+      } catch (error) {
+        errors.push(error instanceof Error ? error : new Error(String(error)));
+      }
+    }
+    throw new AggregateError(errors, 'All handlers failed');
+  }
+}
+export class FallbackUtil {
+  static boolchecker<T>(value: T, condition: boolean): T {
+    if (condition) {
+      return value;
+    } else {
+      throw new Error('Condition is false, throwing error');
+    }
+  }
+}