Toisu! middleware runner

For Node.js versions less than 14 please use the 2.x line of releases.

Toisu! runs middlewares in sequence, waiting for promises from middlwares to resolve (when promises are returned) before continuing to the next. This module contains a function which does this sequential middleware execution. This logic has been placed in its own module since both toisu and toisu-router use it. Other modules intended to work with Toisu! might also find it useful.

usage

Middleware may either be a function which runs synchronously, or one that returns a promise. A mixture of synchronous and asynchronous functions may be used. Note though, that the runner returns a promise and will always resolve asynchronously.

With plain old promises:

import runner from '@toisu/middleware-runner';

// context will be used as the `this` value for middlewares.
runner.call(context, req, res, middlewares)
  .then(responding => {
    // responding is true when either the response headers are sent, or the
    // response is no longer writable for some reason.
  })
  .catch(err => {
    // Run when a middleware threw.
  });

With async-await:

import runner from '@toisu/middleware-runner';

async function example() {
  let responding;

  try {
    responding = await runner.call(context, req, res, middlwares);
  } catch (e) {
    // Handle errors.
    return;
  }

  // responding is true when either the response headers are sent, or the
  // response is no longer writable for some reason.
}