Guardrails & Execution Safety

Volten includes built-in execution checks to prevent common asynchronous pitfalls:

1. Double next() Prevention

Calling next() multiple times in the same middleware causes undefined behavior and race conditions in many frameworks. Volten detects this and throws InvalidNextCallError:

app.use(async (ctx, next) => {
  await next();
  await next(); // Throws InvalidNextCallError!
});

2. Calling next() After Response Sent

If a response has already concluded (ctx.sent === true), invoking next() is rejected to prevent invalid wire writes:

app.use(async (ctx, next) => {
  ctx.send("Completed");
  await next(); // Throws InvalidNextCallError!
});

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