source: imaps-frontend/node_modules/import-fresh/index.js@ d565449

'use strict';
const path = require('path');
const resolveFrom = require('resolve-from');
const parentModule = require('parent-module');

module.exports = moduleId => {
        if (typeof moduleId !== 'string') {
                throw new TypeError('Expected a string');
        }

        const parentPath = parentModule(__filename);

        const cwd = parentPath ? path.dirname(parentPath) : __dirname;
        const filePath = resolveFrom(cwd, moduleId);

        const oldModule = require.cache[filePath];
        // Delete itself from module parent
        if (oldModule && oldModule.parent) {
                let i = oldModule.parent.children.length;

                while (i--) {
                        if (oldModule.parent.children[i].id === filePath) {
                                oldModule.parent.children.splice(i, 1);
                        }
                }
        }

        delete require.cache[filePath]; // Delete module from cache

        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

        return parent === undefined ? require(filePath) : parent.require(filePath); // In case cache doesn't have parent, fall back to normal require
};