The following is the code which looks int the node_modules
folder by default
Module.prototype.load = function(filename) {
debug('load ' + JSON.stringify(filename) +
' for module ' + JSON.stringify(this.id));
assert(!this.loaded);
this.filename = filename;
this.paths = Module._nodeModulePaths(path.dirname(filename));
var extension = path.extname(filename) || '.js';
if (!Module._extensions[extension]) extension = '.js';
Module._extensions[extension](this, filename);
this.loaded = true;
};
So, following is the exact search pattern:
Node.JS looks to see if the given module is a core module.
(e.g. http
, fs
, etc.) Always takes the precedence in the loading
modules.
If the given module is not a core modules(e.g. http
, fs
, etc.), Node.js will then begin to search for a directory named, node_modules
.
It will start in the current directory (relative to the currently-executing file in Node.JS) and then work its way up the folder hierarchy, checking each level for a node_modules folder.
Once Node.JS finds the node_modules
folder, it will then attempt to load the given module either as a (.js) JavaScript file or as a named sub-directory; if it finds the named sub-directory, it will then attempt to load the file in various ways. So, for example
If you make a request to load the module, "utils" and its a directory not a .js file then:
Node.JS will search a hierarchical directory for node_modules
and utils
in the following ways:
./node_modules/utils.js
./node_modules/utils/index.js
./node_modules/utils/package.json
If Node.JS still can't find the file in above steps, Node.js will then start to look into the directory paths from environment variables i.e. NODE_PATH
set on your machine(obviously set by Node.JS installer file if you are on windows)
Not Found in all the above steps then, prints a stack trace to stder
E.g.: Error:
Cannot find module 'yourfile'
For more information: link is here even the cyclic require() is explained very well..
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