PubSubInterceptor

PubSubInterceptor = (next) => PubSubInterceptorFn

Defined in: packages/pubsub/src/types.ts:202

A connectrpc-style interceptor for pubsub transport operations.

Interceptors form a middleware chain around transport publish, delivery, and lifecycle operations. Each interceptor receives a next function and returns a new function that can run logic before and/or after calling next.

const logger: PubSubInterceptor = (next) => async (ctx) => {
  if (ctx.operation === "publish" || ctx.operation === "handle") {
    const start = performance.now();
    try {
      return await next(ctx);
    } finally {
      console.log(`${ctx.operation}: ${performance.now() - start}ms`);
    }
  }
  return next(ctx);
};

// Narrowing on operation:
const metrics: PubSubInterceptor = (next) => async (ctx) => {
  if (ctx.operation === "committed") {
    counter.increment("committed");
  }
  return next(ctx);
};

Parameters

next

PubSubInterceptorFn

Returns

PubSubInterceptorFn