@digitak/grubber/utilities/addJsExtensions.js

Parse code files and patch it without having to use an AST

import Parser from "../Parser.js";
// import { createRequire } from "module"
/**
 * @param resolve callback that take a module endpoint as entry and the right .js file that is imported
 */
export default function addJsExtensions(content, resolve) {
    const dependencies = new Parser(content, "es").findDependencies();
    let result = "";
    let offset = 0;
    for (const dependency of dependencies) {
        const imported = dependency.groups[2].trim();
        const patchedImport = resolve(imported);
        if (patchedImport !== imported) {
            result +=
                content.slice(offset, dependency.start) +
                    dependency.slice.replace(imported, patchedImport);
            offset = dependency.end;
        }
    }
    result += content.slice(offset);
    return result;
}