modules that neither export nor import shouldn't be wrapped in define-call

[jrieken]

Describe the bug

This is maybe controversial and something we can tackle on our end but it is different from how tsc behaves

Input code

namespace foo {
  someglobal.fn();
}

Config

{
  "$schema": "http://json.schemastore.org/swcrc",
  "exclude": "\\.js$",
  "jsc": {
    "parser": {
      "syntax": "typescript",
      "tsx": false,
      "decorators": true
    },
    "target": "es2020",
    "loose": false,
    "minify": {
      "compress": false,
      "mangle": false
    }
  },
  "module": {
    "type": "amd",
    "noInterop": true
  },
  "minify": false
}

Playground link

https://play.swc.rs/?version=1.2.203&code=H4sIAAAAAAAAA8tLzE0tLkhMTlVIy89XqOZSUCjOz01Nz8lPSszRS8vT0LTmqgUAxm2peCQAAAA%3D&config=H4sIAAAAAAAAA0WOTQ6DQAhG70JcNmpceoPewc1kxL84wwQw1RjvXqzR7sjj%2Bx7skIkfMDioYVBNdVFMQjG%2FoCgx5sR9IR%2FPHl6Aq5%2BXFi3dNPkkmaFJPNQ7JMeCfE6yRXWrRXRLKJ7HpBZTMdS5WfAFLXpiZ3KBWnnBw9aOe1QroVRlVVphJhJ8KmGMY7edek8hMYr8Vy728508zBWoXU6w%2Fz4wpwutCSO9oyJTeo7e0qv5BTnH4YgMAQAA

Expected behavior

With tsc the define-call is skipped because the code doesn't export or import anything.

https://www.typescriptlang.org/play?module=2#code/HYQwtgpgzgDiDGEAEAzA9mpBvAUEpUakA5gDZoBGIpAdCsABQCUA3DgL5A

Actual behavior

The code is wrapped in a define call making it hard ti transpile code that actually bootstraps the AMD logic

Version

1.2.203

Additional context

relates to, but not strictly needed for, microsoft/vscode#150025

[magic-akari]

Input

const hello = "world";
console.log(hello);

• rollup.js

define((function () { 'use strict';

	const hello = "world";
	console.log(hello);

}));

[kdy1]

I think we should follow behavior of tsc for ts-specific things

TSC: https://www.typescriptlang.org/play?#code/HYQwtgpgzgDiDGEAEAzA9mpBvAUEpUakA5gDZoBGIpAdCsABQCUA3DgL5A

[kdy1]

You can use isModule: "unknown" to make swc behave identical as tsc. (While allowing other files to be handled as module)

https://play.swc.rs/?version=1.2.203&code=H4sIAAAAAAAAA8tLzE0tLkhMTlVIy89XqOZSUCjOz01Nz8lPSszRS8vT0LTmqgUAxm2peCQAAAA%3D&config=H4sIAAAAAAAAA0WOTQ6CQAxG79KwNGBccgMX3sDNZKgIMu2kLRFCuLvFH9w1r9%2F32gUKjXdMAWq4m%2BW6qnplKj9QjQVLlrbSZ5QIB8ApDmODnr5ey14LR71GqBfIQRRlm3QmC5NHbM6oUbpsHjN1dAuD4gEajCzB5Qq1yYirr4O0aF5CPR1PRy8MzIp7JXXU3eZNHzllQdX%2FKlA7%2FJKruxI34waW9wfuDKlxIfGZDIXzfvQn%2FYo6vXybMNKD%2BEmwvgDqvBMKIQEAAA%3D%3D

But .swcrc does not support this field...

How do you invoke swc?

[magic-akari]

You can use isModule: "unknown" to make swc behave identical as tsc. (While allowing other files to be handled as module)

https://play.swc.rs/?version=1.2.203&code=H4sIAAAAAAAAA8tLzE0tLkhMTlVIy89XqOZSUCjOz01Nz8lPSszRS8vT0LTmqgUAxm2peCQAAAA%3D&config=H4sIAAAAAAAAA0WOTQ6CQAxG79KwNGBccgMX3sDNZKgIMu2kLRFCuLvFH9w1r9%2F32gUKjXdMAWq4m%2BW6qnplKj9QjQVLlrbSZ5QIB8ApDmODnr5ey14LR71GqBfIQRRlm3QmC5NHbM6oUbpsHjN1dAuD4gEajCzB5Qq1yYirr4O0aF5CPR1PRy8MzIp7JXXU3eZNHzllQdX%2FKlA7%2FJKruxI34waW9wfuDKlxIfGZDIXzfvQn%2FYo6vXybMNKD%2BEmwvgDqvBMKIQEAAA%3D%3D

But .swcrc does not support this field...

How do you invoke swc?

cannot agree more.
If there is neither an export nor an import in the file, TypeScript assumes it is a script.

[kdy1]

@magic-akari Do you mean we should support it in .swcrc?

[magic-akari]

@magic-akari Do you mean we should support it in .swcrc?

Sure. We can follow Babel config. https://babeljs.io/docs/en/options#sourcetype

---

FYI https://devblogs.microsoft.com/typescript/announcing-typescript-4-7/#control-over-module-detection

[jrieken]

@kdy1 Is https://swc.rs/docs/configuration/compilation#multiple-entries actually supported inside .swcrc? E.g declaring an array of configs in it I get errors complaining about invalid JSON

[kdy1]

Yes, but note that regex syntax is one of rust regex crate

[kdy1]

@jrieken Can you share your .swcrc?

[jrieken]

@kdy1 there you go. It looks like it failing as soon as I put the config-object into an array (e.g works when it's a top-level object)

[
	{
		"test": "\\.ts$",
		"jsc": {
			"parser": {
				"syntax": "typescript",
				"tsx": false,
				"decorators": true
			},
			"target": "es2020",
			"loose": false,
			"minify": {
				"compress": false,
				"mangle": false
			}
		},
		"module": {
			"type": "amd",
			"noInterop": true
		},
		"minify": false
	}
]

[kdy1]

Hmm....
Seems like deserialization itself is successful

[jrieken]

Funny... I see the error below running npx swc --config-file .swcrc src --copy-files --out-dir out in this branch (https://github.com/microsoft/vscode/tree/joh/swc)

jrieken@jrieken-m1-pro vscode % npx swc --config-file .swcrc src --copy-files --out-dir out
failed to process input file

Caused by:
    0: failed to read swcrc file (src/bootstrap-amd.js)
    1: failed to process config file
    2: .swcrc exists but not matched

[kwonoj]

@jrieken I.. don't think we support top level array as config unless if I miss something? Please allow me a dumb q, any specific reason you need to use array instead of an object for the swcrc config?

[kdy1]

@kwonoj We support top level array.
The screenshot is about the array config test

[swc-bot]

This closed issue has been automatically locked because it had no new activity for a month. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.