In JavaScript, when using module systems like CommonJS or ES modules, plugin and preset files are not allowed to directly export objects. They can only export functions. This limitation is enforced to maintain consistency and avoid potential issues related to object exports.
To understand this better, let’s consider an example where we have a plugin file called “myPlugin.js” and it needs to export a configuration object. Instead of directly exporting the object, we need to wrap it in a function and export that function. This allows the receiving module to execute the function and get the desired object as a result.
myPlugin.js:
// Plugin code...
function getPluginConfig() {
return {
// Configuration object...
};
}
module.exports = getPluginConfig;
By exporting the getPluginConfig function, the object can be obtained by executing the function in the importing module. For example:
import getPluginConfig from ‘./myPlugin.js’;
const pluginConfig = getPluginConfig();
// Use the obtained object…
This way, plugin/preset files can only export functions, ensuring that the receiving module executes the function to obtain the desired configuration object. It adds an extra layer of abstraction and encapsulation, preventing direct object exports.