Middleware to turn off caching

It's possible that you've got bugs in an old HTML or JavaScript file, and with a cache, some users will be stuck with those old versions. This will (try to) abolish all client-side caching.

var nocache = require('nocache')
app.use(nocache())

This sets four headers, disabling a lot of browser caching:

• Cache-Control: no-store, no-cache, must-revalidate, proxy-revalidate
• Pragma: no-cache
• Expires: 0
• Surrogate-Control: no-store

If you want to crush the ETag header as well, you can:

app.use(nocache({ noEtag: true }))

Caching has some real benefits, and you lose many of them here. Browsers won't cache resources with this enabled, although some performance is retained if you keep ETag support. It's also possible that you'll introduce new bugs and you'll wish people had old resources cached, but that's less likely.