[BUG] Using esbuild to generate an ESM .mjs bundle #295
Description
when trying to run this library as an ESM, for instance using esbuild to generate a .mjs file. It fails tu run on AWS lambda with this error:
2025-11-10T21:22:36.250Z undefined ERROR Uncaught Exception
{
"errorType": "Error",
"errorMessage": "Dynamic require of \"querystring\" is not supported",
"stack": [
"Error: Dynamic require of \"querystring\" is not supported",
" at file:///var/task/api.mjs:1:388",
" at <anonymous> (/var/node_modules/lambda-api/lib/request.js:8:12)",
" at file:///var/task/api.mjs:1:499",
" at <anonymous> (/var/node_modules/lambda-api/index.js:8:17)",
" at file:///var/task/api.mjs:1:499",
" at <anonymous> (/var/apps/api/shells/input/api-gateway-shell.ts:3:23)",
" at ModuleJob.run (node:internal/modules/esm/module_job:343:25)",
" at async onImport.tracePromise.__proto__ (node:internal/modules/esm/loader:647:26)",
" at async _tryAwaitImport (file:///var/runtime/index.mjs:1098:16)",
" at async _tryRequire (file:///var/runtime/index.mjs:1156:86)"
]
}By adding this
banner: {
js: "import { createRequire } from 'module'; const require = createRequire(import.meta.url);",
},to your esbuild build configuration, or manually adding that line at the top of the output bundled file it works on AWS Lambda using ESM and an MJS entrypoint file.