node.js require() cache - possible to invalidate?

Question

From the node.js documentation:

Modules are cached after the first time they are loaded. This means (among other things) that every call to require(\'

Answer 1

Yes, you can access the cache via require.cache[moduleName] where moduleName is the name of the module you wish to access. Deleting an entry by calling delete require.cache[moduleName] will cause require to load the actual file.

This is how you would remove all cached files associated with the module:

/**
 * Removes a module from the cache
 */
function purgeCache(moduleName) {
    // Traverse the cache looking for the files
    // loaded by the specified module name
    searchCache(moduleName, function (mod) {
        delete require.cache[mod.id];
    });

    // Remove cached paths to the module.
    // Thanks to @bentael for pointing this out.
    Object.keys(module.constructor._pathCache).forEach(function(cacheKey) {
        if (cacheKey.indexOf(moduleName)>0) {
            delete module.constructor._pathCache[cacheKey];
        }
    });
};

/**
 * Traverses the cache to search for all the cached
 * files of the specified module name
 */
function searchCache(moduleName, callback) {
    // Resolve the module identified by the specified name
    var mod = require.resolve(moduleName);

    // Check if the module has been resolved and found within
    // the cache
    if (mod && ((mod = require.cache[mod]) !== undefined)) {
        // Recursively go over the results
        (function traverse(mod) {
            // Go over each of the module's children and
            // traverse them
            mod.children.forEach(function (child) {
                traverse(child);
            });

            // Call the specified callback providing the
            // found cached module
            callback(mod);
        }(mod));
    }
};

Usage would be:

// Load the package
var mypackage = require('./mypackage');

// Purge the package from cache
purgeCache('./mypackage');

Since this code uses the same resolver require does, just specify whatever you would for require.

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"Unix was not designed to stop its users from doing stupid things, as that would also stop them from doing clever things." – Doug Gwyn

I think that there should have been a way for performing an explicit uncached module loading.