npm link local modules nodejs scripts.

postinstall.js

const assert = require('assert');
const {promisify} = require('util');
const fs = require('fs');
const {resolve} = require('path');

//
const symlink = promisify(fs.symlink);
const stat = promisify(fs.stat);
const mkdir = promisify(fs.mkdir);

// Is path exists
async function isExists(p) {
  try {
    await stat(p);
    return true;
  } catch (error) {
    return false;
  }
}

// ensure folder exists.
async function ensureFolder(folder) {
  if (!(await isExists(folder))) {
      await mkdir(folder);
      console.log({folder});
    }
}

// ---

const rootDir = resolve(__dirname, '..');
const NODE_MODULES = resolve(rootDir, 'node_modules');

const modulesMap = {
  '@wisetc/styledComponents': resolve(rootDir, '../testproject/dist'),
}

async function linkModules() {
  assert(process.platform === 'win32', 'Only windows platform support now.');
  const dirType = 'dir'; // 'junction'

  const promises = [];
  for (const module in modulesMap) {
    const target = modulesMap[module];
    const linkPath = resolve(NODE_MODULES, module);
    const folderName = resolve(linkPath, '..');
    await ensureFolder(folderName);
    console.log({linkPath, target});

    promises.push(symlink(target, linkPath, dirType));
  }

  const results = await Promise.all(promises);
  return results;
}

async function main() {
  try {
    await linkModules();
    console.log('done');
  } catch (error) {
    console.error(error.message);
  }
}

main();