2 const path = require('path');
3 const resolveFrom = require('resolve-from');
4 const parentModule = require('parent-module');
6 module.exports = moduleId => {
7 if (typeof moduleId !== 'string') {
8 throw new TypeError('Expected a string');
11 const parentPath = parentModule(__filename);
13 const filePath = resolveFrom(path.dirname(parentPath), moduleId);
15 const oldModule = require.cache[filePath];
16 // Delete itself from module parent
17 if (oldModule && oldModule.parent) {
18 let i = oldModule.parent.children.length;
21 if (oldModule.parent.children[i].id === filePath) {
22 oldModule.parent.children.splice(i, 1);
27 delete require.cache[filePath]; // Delete module from cache
29 const parent = require.cache[parentPath]; // If `filePath` and `parentPath` are the same, cache will already be deleted so we won't get a memory leak in next step
31 return parent === undefined ? require(filePath) : parent.require(filePath); // In case cache doesn't have parent, fall back to normal require