SWC ignore .swcrc config

[Kaizer69]

Desired Behavior

When use ts-node, you should use default swcrc that ts-node create, but if is present a .swcrc file, you should use that file.

Is this request related to a problem?

Yes, because if I have a JS file with private members (hash # char), SWC wont compile

[cspotcode]

What's your .swcrc look like?

[Kaizer69]

{
  "$schema": "https://json.schemastore.org/swcrc",
  "exclude": [".*.js$", ".*.map$"], <<<<<<<<<<-------------
  "jsc": {
    "parser": {
      "syntax": "ecmascript",
      "jsx": false,
      "dynamicImport": false,
      "privateMethod": true, <<<<<<<<<<-------------
      "functionBind": false,
      "exportDefaultFrom": false,
      "exportNamespaceFrom": false,
      "decorators": true,
      "decoratorsBeforeExport": false,
      "topLevelAwait": false,
      "importMeta": false
    },
  },
}

I try to pure an invalid .swcrc and ts-node start without problems. The configuration is skipped.
I want to exclude JS (that SWC can parse for private methods) or use privateMethod flag of SWC.

Is possibile enable swcrc flag (actually swcrc: false) here?

Here the error using SWC:

........@swc\helpers\lib\_class_check_private_static_access.js:8
        throw new TypeError("Private static access of wrong provenance");
              ^
TypeError: Private static access of wrong provenance

[cspotcode]

Is there a minimal example of the .js file raising this error?

[Kaizer69]

I cannot provide the example, because the JS lib that I've use is highly obfuscated, so it's difficult extract only the private part.

[cspotcode]

It can be a new one, just needs to be an example that can be used to test with. Requesting a minimal reproducible example is common practice in open-source: https://en.wikipedia.org/wiki/Minimal_reproducible_example

[vinczebalazs]

I have the same problem also, any .swcrc config fileis ignored.

[cajoy]

The same here

[falkenhawk]

Is it really necessary for ts-node to tell swc to ignore .swcrc altogether by this setting?
https://github.com/TypeStrong/ts-node/blob/main/src/transpilers/swc.ts#L222

[radriaanse]

Slightly different use case here, using the .swcrc file to specify path mappings like;

  "jsc": {
    "paths": {
      "@/some/*": ["thing/*"],
    },

ts-node could optionally allow specifying these (or fetching them from the tsconfig.json) but if we could enable loading the .swcrc ts-node doesn't have to be updated every time new options become available in swc.

[mmazzarolo]

For what is worth, for a quick patch, changing swcrc: false to true using patch-package is enough to make it work.

Diff here:

diff --git a/node_modules/ts-node/dist/transpilers/swc.js b/node_modules/ts-node/dist/transpilers/swc.js
index eeddd4f..563c253 100644
--- a/node_modules/ts-node/dist/transpilers/swc.js
+++ b/node_modules/ts-node/dist/transpilers/swc.js
@@ -165,7 +165,7 @@ function createSwcOptions(compilerOptions, nodeModuleEmitKind, swcInstance, swcD
                     ignoreDynamic: nodeModuleEmitKind === 'nodecjs',
                 }
                 : undefined,
-            swcrc: false,
+            swcrc: true,
             jsc: {
                 externalHelpers: importHelpers,
                 parser: {

[vagusX]

I think it's necessary for ts-node to expose the reading behavior of swc, especially since the @swc/[email protected] version was recently updated with the useDefineForClassFields option enabled by default, which has caused inconsistent compilation behavior for class properties compared to tsc.

[vagusX]

Otherwise shall we disable useDefineForClassFields firstly? #1968

[rafaelliu]

Also interested in this, same issue with useDefineForClassFields. Merging a explicitly defined .swcrc would be nice, but just exposing useDefineForClassFields would do it on my case

[danielbayerlein]

Any news?

[tyteen4a03]

Bump - this prevents us from adopting React 17 Transform as we're unable to override .swcrc.

[sdotson]

Also curious

[mkovel]

any news?

[hanseltime]

I too would like to use the swc but I have multiple prod/dev .swcrc files that I need to be able to indicate. I have gone ahead and implemented a basic PR, however the yarn version is a blocker for me to install and run tests reliably.

#2143

This is an easy win as long as someone can either take over writing the tests or can point me to documentation for setting up and running tests reliably. The PR itself should be pretty innocuous since it's only adding an option argument and defaults back to the original settings if it's not provided.