Import assertions are not getting stripped out of dynamic import

[tinovyatkin]

Import assertions are mandatory in dynamic import of JSON modules also, starting Node 16.14 - see https://nodejs.org/docs/latest-v16.x/api/esm.html#import-assertions

But they are resulting in error on previous versions of Node, and so, should be stripped when target is below 16.14 (just like with standard import).

I.e.:

// source
const { default: barData } =
  await import('./bar.json', { assert: { type: 'json' } });

// should stay like this with `target: 'node16.14'`, but should be converted into following with `target: 'node16.13.2`:
const { default: barData } = await import('./bar.json');

[evanw]

This appears to be working correctly:

$ echo "import('./bar.json', { assert: { type: 'json' } })" | esbuild --target=node16.14
import("./bar.json", { assert: { type: "json" } });

$ echo "import('./bar.json', { assert: { type: 'json' } })" | esbuild --target=node16.13.2
import("./bar.json");

Are you sure you are using the latest version? What are the steps to reproduce the issue?

[tinovyatkin]

Hmm, maybe there is something in details then. I do bundle actually:

Source file, import-test.ts:

import staticImport from 'test.json' assert { type: 'json' };
console.log('static import transpiles well', staticImport);

export const schemaDocument = (
  await import(process.env.SCHEMA_LOCATION!, { assert: { type: 'json' } })
).default;

Bundle:

$ npx esbuild --bundle ./import-test.ts --target=node16.13.2 --format=esm --external:test.json
// ./import-test.ts
import staticImport from "test.json";
console.log('static import transpiles well', staticImport);
var schemaDocument = (await import(process.env.SCHEMA_LOCATION, { assert: { type: "json" } })).default;
export {
  schemaDocument
};

$ npx esbuild --bundle ./import-test.ts --target=node16.14 --format=esm --external:test.json
// ./import-test.ts
import staticImport from "test.json" assert { type: "json" };
console.log('static import transpiles well', staticImport);
var schemaDocument = (await import(process.env.SCHEMA_LOCATION, { assert: { type: "json" } })).default;
export {
  schemaDocument
};

[hyrious]

It seems esbuild cannot handle non-string tokens as the first param of import().
(live link).

import(a, { assert: { type: 'json' } })

[evanw]

Ah, that makes sense. Looks like I missed one of the cases. Will fix.