Analyze "module" exports of high-impact npm packages

readme.txt

$ node check.mjs
High-impact npm packages: 7007
Packages with exports: 1126
Packages with "module" exports: 44
- tslib
- uuid
- @emotion/memoize
- es-module-lexer
- @emotion/unitless
- @emotion/hash
- underscore
- @emotion/is-prop-valid
- @emotion/utils
- @emotion/serialize
- @emotion/cache
- @emotion/sheet
- @emotion/weak-memoize
- react-select
- @emotion/react
- @emotion/babel-plugin
- @emotion/use-insertion-effect-with-fallbacks
- idb
- @emotion/styled
- @floating-ui/dom
- @floating-ui/core
- @emotion/css
- @azure/msal-common
- react-error-boundary
- mitt
- @floating-ui/react-dom
- react-textarea-autosize
- react-i18next
- @azure/msal-browser
- zustand
- @azure/msal-node
- @floating-ui/utils
- vuex
- @fortawesome/fontawesome-svg-core
- @firebase/messaging
- swr
- use-debounce
- i18next-browser-languagedetector
- redux-saga
- react-virtualized-auto-sizer
- dexie
- @emotion/babel-preset-css-prop
- @polkadot/util
- @polkadot/api
Packages with "module" export before "import": 34
Packages with "module" export before "default": 5

check.mjs

import {npmHighImpact} from 'npm-high-impact'
import {readFileSync, existsSync, writeFileSync} from "node:fs";

void main();

async function main() {
    const pkgs = await getPackages();
    const exports = pkgs.filter(pkg =>
        hasExports(pkg, (obj => {
            return true;
        }))
    );
    const moduleExport = pkgs.filter(pkg =>
        hasExports(pkg, (obj => {
            return "module" in obj;
        }))
    );
    const moduleBeforeImport = pkgs.filter(pkg =>
        hasExports(pkg, (obj => {
            const keys = Object.keys(obj);
            const moduleIndex = keys.indexOf("module");
            const importIndex = keys.indexOf("import");
            if (moduleIndex >= 0 && importIndex >= 0) {
                return moduleIndex < importIndex;
            }
            return false;
        }))
    );
    const moduleBeforeDefault = pkgs.filter(pkg =>
        pkg.type === "module" &&
        hasExports(pkg, (obj => {
            const keys = Object.keys(obj);
            const moduleIndex = keys.indexOf("module");
            const defaultIndex = keys.indexOf("default");
            if (moduleIndex >= 0 && defaultIndex >= 0) {
                return moduleIndex < defaultIndex;
            }
            return false;
        }))
    );
    console.log(`High-impact npm packages: ${npmHighImpact.length}`);
    console.log(`Packages with exports: ${exports.length}`);
    console.log(`Packages with "module" exports: ${moduleExport.length}`);
    for (const pkg of moduleExport) {
        console.log(`- ${pkg.name}`);
    }
    console.log(`Packages with "module" export before "import": ${moduleBeforeImport.length}`);
    console.log(`Packages with "module" export before "default": ${moduleBeforeDefault.length}`);
}

/**
 * @return {Promise<object[]>}
 */
async function getPackages() {
    const pkgsFile = "pkgs.json";
    let pkgs = {};
    if (existsSync(pkgsFile)) {
        pkgs = JSON.parse(readFileSync(pkgsFile, "utf-8"));
    }
    for (const name of npmHighImpact) {
        if (name in pkgs) {
            continue;
        }
        console.log(`fetching ${name}`);
        const res = await fetch(`https://registry.npmjs.com/${name}/latest`);
        pkgs[name] = await res.json();
        writeFileSync(pkgsFile, JSON.stringify(pkgs));
    }
    return Object.values(pkgs);
}

/**
 * @callback hasExports~fn
 * @param {object} obj
 * @return {boolean}
 */
/**
 * @param {object} pkg
 * @param {hasExports~fn} fn
 * @return {boolean}
 */
function hasExports(pkg, fn) {
    if (!("exports" in pkg)) {
        return false;
    }
    function recurse(obj) {
        if (obj === null) {
            return false;
        }
        if (typeof obj !== "object") {
            return false;
        }
        const r = fn(obj);
        if (r) {
            return true;
        }
        for (const val of Object.values(obj)) {
            if (recurse(val)) {
                return true;
            }
        }
        return false;
    }
    return recurse(pkg.exports);
}