Removes a module and all of its dependents from the require cache
npm install invalidate-module 
Removes a module and all of its dependents from the require cache, so that
subsequent requires of that module or any of its dependents will return new
copies.
Useful for implementing a hot-reloading environment for Node.js programs in
watch mode.
e.g. iterating on a static site generator that uses server side rendered
React components for templating.
``
npm install invalidate-module
Start the module dependencies tracking by requiring invalidate-module.
`js`
const invalidate = require('invalidate-module');
Call invalidate() with the absolute path of a module to remove it and itsrequire.cache
dependents from .
`js`
invalidate(require.resolve('./my-module'));
Note that you must provide the absolute path of the module, so use something
like [require.resolve()][r] or [path.resolve()][p].
Example when used with a watcher like [chokidar][c]:
index.jsjs
const chokidar = require('chokidar');
const path = require('path');
const invalidate = require('invalidate-module');
const watcher = chokidar.watch('.', { ignoreInitial: true });
require('./a');
watcher.on('all', (event, filename) => {
invalidate(path.resolve(filename));
require('./a');
});
`
a.jsjs`
require('./b');
console.log('this is module a');
b.jsjs`
console.log('this is module b');
Running index.js will call require('./a') which prints:`
this is module b
this is module a
If you make this change to a.js and save:`js`
require('./b');
console.log('this is module a v2');
The watcher callback will fire and invalidate a.js so that require('./a')
loads the new version and this gets logged:
this is module a v2
Because b.js is still in require.cache, the require('./b') does nothing.
If you make this change to b.js and save:`js`
console.log('this is module b v2');
b.js and its dependent a.js will be invalidated and it will log:`
this is module b v2
this is module a v2
At the time of requiring this module, node's require() is monkey-patched soinvalidate()
that subsequent calls will add the caller module and the required module to a
graph. When you call on a module, it deletes the module fromrequire.cache and then it uses the graph to get the module's dependents andrequire.cache
deletes them from as well.
Running with env vars DEBUG=invalidate-module will log the modules that arerequire.cache`.
deleted from
[c]: https://github.com/paulmillr/chokidar
[p]: https://nodejs.org/api/path.html#path_path_resolve_paths
[r]: https://nodejs.org/api/globals.html#globals_require_resolve