ebdrup/moduleconfig

loading configuration files for node modules

moduleconfig

loading configuration files for node modules. If you are building a node module that needs a configuration file, that the user of the module creates, you have come to the right place.

You are building a module MyModule with a user config file

The module MyModule has a configuration, by convention this configuration specified in in the file config.js.

• In project Main the module MyModule is required.
• In project Main the module ExternalModule is also required.
• ExternalModule also requires MyModule

This means that when the module ExternalModule uses MyModule the configuration should be loaded from Main/node_modules/ExternalModule/config.js, and when the project Main uses the module MyModule the configuration should be loaded from Main/config.js

Problem

Because Main and ExternalModule both require the same version of MyModule. npm only installs MyModule in Main/node_modules/MyModule. MyModule is not installed in Main/node_modules/ExternalModule/node_modules/MyModule.

Therefore the require-ing MyModule from the code ExternalModule in does not load the correct config. It loads the config from Main/config.js and not from Main/node_modules/ExternalModule/config.js as it should. The Main projects config overrides the ExternalModule config.

Solution

Use moduleconfig in the module MyModule

MyModule.js is the main file pointed to by the package.json in the MyModule module

var moduleConfig = require("moduleconfig");
module.exports = moduleConfig(["config.js"], function(configFilePath){
	return instantiateMyModulefromConfig(require(configFilePath));
});

You will have to implement the instantiateMyModulefromConfig function yourself.

This will mean that this:

var myModule = require("MyModule");

will return an myModule based on Main/node_modules/ExternalModule/config.js when MyModule is required from a javascript file anywhere in the path Main/node_modules/ExternalModule/...

and it will return an myModule based on Main/config.js when MyModule is required by code in Main.

License

MIT