node-server-timing

Record server timings and respond via a Server Timing header.

Express Example

const { Express : ExpressTiming } = require('../index');

const express = require('express');
const app     = express();

app.use(ExpressTiming.init());

app.get('/', (req, res) => {
    req.startTiming('foo', 'Doing the foo');
    req.startTiming('bar', 'Barring the bar');
    req.startTiming('baz', 'Just bazin');

    setTimeout(() => {
        res.stopTiming('bar');
    }, 100);

    setTimeout(() => {
        res.stopTiming('baz');
    }, 300);

    setTimeout(() => {
        res.stopTiming('foo');

        res.send('Hello World!');
    }, 500);
});

app.listen(3000, () => {
    console.log('Example app listening on port 3000!')
});

The express middleware adds the startTiming and stopTiming methods onto both the req and res so they can be used interchangeably.

The startTiming method accepts two arguments:

• key The key of the timing. This can be used when you stop the timer.
• description A short description of the timer. This defaults to the key if not provided.

The startTiming method also returns the timer with a handy stop and clear method on it:

const timer = req.startTiming('foo');

// same as executing req.startTiming('foo');
timer.stop();
// removes the timer
timer.clear();

The stopTiming method only accepts a single argument:

• key The key used to start a timer.