test.js

{
    function makeBody(body, ex, im){
         return `function (${im}) {
            ${body}
            return ${ex};
        }`   
    }
    const im_re = /(?:^|\s|;)import +(\S[\S\s]*?) +from +"(\S+)" *;/;
    const ex_re = /(?:^|\s|;)export +default +(\S+);$/;

    function loadModule(modules) {
        //file을 모듈로 만드는건 그냥 나중에 구현하도록 하자.
    }
    const modules = {
        a: {
            dep: ['b','c'],
            body: makeBody('console.log(b(), c());', '', 'b,c'),
            c: false
        },
        b: {
            dep: [],
            body: makeBody('var f = function () {return 2}', 'f', ''),
            c: false   
        },
        c: {
            dep: [],
            body: makeBody('var f = function () {return 3}', 'f', ''),
            c: false
        },
        d: {
            dep: ['b'],
            body: makeBody('console.log(b())', '', 'b'),
            c: false
        }
    }
    function makeModule(ms) {
        return Object.entries(ms).reduce((res, [name, m]) => {
            res +=`__mo['${name}'] = ${m.body};`
            return res;
        }, '');
    }
    function makeDep(name, m, dep) {
        if (dep.includes(name)) {
            throw new Error('circle dependency.')
        }
        const d = [...dep, name]
        if (m.c) {
            return `__ca['${name}']`;
        }
        const res = `__ca['${name}']=__mo['${name}'](${m.dep.map((dm)=>makeDep(dm, modules[dm], d)).join(',')})`
        m.c = true;
        return res;
    }
    function makeAllDep(ms) {
        return Object.entries(ms).reduce((res, [name, m]) => {
            return m.c ? res : `${res};${makeDep(name, m, [])}`
        }, '');
    }
    function build(ms) {
        return `(function(){var __mo={},__ca={};${makeModule(ms)};${makeAllDep(ms)}})()`
    }
    build(modules);
}