Import external dependencies into Postman

import-external-dependencies.js

const CACHE_KEY = '__importCache'
const importCacheLayer = pm.environment.has(CACHE_KEY)
  ? pm.environment
  : pm.collectionVariables.has(CACHE_KEY)
    ? pm.collectionVariables
    : pm.globals.has(CACHE_KEY)
      ? pm.globals
      : pm.variables;
  
const __import = (url, options = { timeout: 20_000}) => {
  const moduleCacheKey = `${CACHE_KEY}:${url}`;
  if (importCacheLayer.has(moduleCacheKey)) {
    return Promise.resolve(new Function(importCacheLayer.get(moduleCacheKey))());
  }

  return new Promise((resolve, reject) => {
    const fetchTimeout = setTimeout(() => {
      reject(new Error(`timeout waiting for import: ${url}`));
    }, options.timeout);

    pm.sendRequest(url, (err, res) => {
      if (err) {
        reject(err);
        clearTimeout(fetchTimeout);
        return;
      }

      const contents = res.text();
      if (JSON.parse(importCacheLayer.get(CACHE_KEY) || 0)) {
        importCacheLayer.set(moduleCacheKey, contents);
      }

      resolve(new Function(contents)());
      clearTimeout(fetchTimeout);
    });
  });
};

(async function main() {
  await __import('https://cdn.jsdelivr.net/npm/js-yaml');
  console.log(jsyaml.load(`---
    hi: there`));
})();