feat: 🎸 implement concurrency() class method decorator

src/concurrencyDecorator.ts

@@ -0,0 +1,18 @@
+import {concurrency as _concurrency} from './concurrency';
+
+/**
+ * A class method decorator that limits the concurrency of the method to the
+ * given number of parallel executions. All invocations are queued and executed
+ * in the order they were called.
+ */
+export function concurrency<This, Args extends any[], Return>(limit: number) {
+  return (
+    target: (this: This, ...args: Args) => Promise<Return>,
+    context?: ClassMethodDecoratorContext<This, (this: This, ...args: Args) => Promise<Return>>,
+  ) => {
+    const limiter = _concurrency(limit);
+    return async function (this: This, ...args: Args): Promise<Return> {
+      return limiter(async () => await target.call(this, ...args));
+    };
+  };
+};

src/index.ts

@@ -2,6 +2,7 @@ export * from './base64';
 export * from './Cache';
 export * from './codeMutex';
 export * from './concurrency';
+export {concurrency as concurrencyDecorator} from './concurrencyDecorator';
 export * from './dataUri';
 export * from './Defer';
 export * from './fanout';