Dynamic import ESM based dependency in Typescript CJS based repo #1077
Description
Runtime
node.js
Runtime version
20.16.0
Module version
25.3.1
Last module version without issue
No response
Used with
No response
Any other relevant information
No response
What are you trying to achieve or the steps to reproduce?
I have CJS based repo written in Typescript which needs to use ESM-only dependency. I do it by dynamically importing that dependency. Code works correctly when run, but fails to compile during test run.
I use lab with typescript
option as advised by docs. In my tsconfig.json
I use compilerOptions.module: "Node16"
to enable native ECMAScript module support (as per Typescript docs). When running test I get
Unexpected token 'export'
Reason is found in typescript.js file, which is used when typescript
option is passed. Mentioned line overrides repos tsconfig option and disables possibility to dynamically import ESM dependency. When I comment out that override, code compiles correctly during test run.
I am not sure whether it is a bug or intended behaviour. If it is intended what is designed way to run my scenario?
How to reproduce?
package.json
{
"name": "lab-test",
"version": "1.0.0",
"main": "./dist/src/index.js",
"scripts": {
"dist": "rm -rf dist && tsc",
"start": "node ./dist/src/index.js",
"test": "lab --typescript"
},
"files": ["dist", "src"],
"license": "ISC",
"devDependencies": {
"@hapi/code": "^9.0.3",
"@hapi/lab": "^25.3.1",
"@types/node": "^20.16.0",
"typescript": "^5.6.2"
},
"dependencies": {
"p-map": "^7.0.2"
}
}
tsconfig.json
{
"compilerOptions": {
"module": "Node16",
"moduleResolution": "Node16",
"target": "ES2023",
"outDir": "dist/",
"rootDir": "./",
"noEmit": false
},
"files": ["src/utils.ts", "src/index.ts"]
}
src/index.ts
import { isPMapImported } from './utils';
isPMapImported();
src/utils.ts
export const isPMapImported = async () => {
// p-map is ESM only dependency
const Pmap = (await import('p-map')).default;
console.log('Is Pmap imported: ', !!Pmap);
}
test/utils.ts
import * as Lab from "@hapi/lab";
import { expect } from "@hapi/code";
import { isPMapImported } from "../src/utils";
const lab = Lab.script();
const { describe, it, before } = lab;
export { lab };
describe("experiment", () => {
before(() => {});
it("is p-map imported", async () => {
await isPMapImported();
// assertion doesn't matter as compilation error will happen
expect(true).to.be.true();
});
});
When running:
npm run dist && npm run start
(runs dist index.js) I get logIs Pmap imported: true
npm run test
I get compilation error
When I comment out line 29 in node_modules/@hap/lab/lib/modules/typescript.js and run npm run test
I get log Is Pmap imported: true
and test succeeds
What was the result you got?
Compilation error
Failed tests:
1) experiment is p-map imported:
Unexpected token 'export'
at wrapSafe (node:internal/modules/cjs/loader:1281:20)
at Module._compile (node:internal/modules/cjs/loader:1321:27)
at Object.require.extensions.<computed> [as .js] (/Users/leszek_pawlega/git/lab-test/node_modules/@hapi/lab/lib/modules/transform.js:41:28)
at Module.load (node:internal/modules/cjs/loader:1208:32)
at Function.Module._load (node:internal/modules/cjs/loader:1024:12)
at Module.require (node:internal/modules/cjs/loader:1233:19)
at require (node:internal/modules/helpers:179:18)
at /Users/leszek_pawlega/git/src/isPMapImported.ts:3:17
at isPMapImported (/Users/leszek_pawlega/git/src/isPMapImported.ts:3:17)
at /Users/leszek_pawlega/git/test/isPMapImported.ts:14:5
at Immediate.<anonymous> (/Users/leszek_pawlega/git/lab-test/node_modules/@hapi/lab/lib/runner.js:659:21)
What result did you expect?
Test will pass
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