[@swc/core@1.3.7 + ] index out of bounds: the len is 1 but the index is 1

[mizi-lin]

Describe the bug

thread '<unnamed>' panicked at 'index out of bounds: the len is 1 but the index is 1', /Users/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/swc_common-0.29.6/src/syntax_pos/hygiene.rs

env: typescript v4.8.4

in @swc/core v1.3.6 ok

Input code

// 
class HuluCssModules extends Visitor {
  visitImportDeclaration(expression) {
     return expression;
  }      
}

exports.default = HuluCssModules;

### Config

```json
{
            test: /\.(js|mjs|jsx|ts|tsx)$/,
            exclude: /node_modules/,
            use: {
                loader: require.resolve('swc-loader'),
                options: {
                    parseMap: true,
                    sync: true,
                    jsc: {
                        parser: {
                            syntax: 'typescript',
                            tsx: true
                        },
                        transform: {
                            react: {
                                runtime: 'automatic',
                                throwIfNamespace: true,
                                development: devMode,
                                useBuiltins: false,
                                refresh: true
                            }
                        }
                    },
                    plugin: (m) => new HuluCssModules().visitProgram(m)
                }
            }
        }

### Playground link

_No response_

### Expected behavior

compile no error

### Actual behavior

_No response_

### Version

v1.3.10

### Additional context

_No response_

[longlho]

I'm also seeing this in our formatjs swc plugin

[kdy1]

@longlho Can you provide a repro case?

[longlho]

It's a little hard to isolate it because our plugin does a bunch of transformations, but specifically this test fail:
Test: https://github.com/formatjs/formatjs/blob/main/packages/swc-plugin/tests/issue-3362.test.ts
Fixture: https://github.com/formatjs/formatjs/blob/main/packages/swc-plugin/tests/fixtures/issue-3362.tsx
The dep upgrade bot put up the PR: formatjs/formatjs#3846 which failed our build
Build log: https://app.buildbuddy.io/invocation/5bac68ac-7edb-48a2-8018-b8a6bb32faf1

In the fixture our plugin basically tries to find all intl.formatMessage and transform the params (removing/adding some attributes). In the test specifically it's mainly a no-op since it just makes sure our plugin doesn't bomb swc. The result snapshot is here: https://github.com/formatjs/formatjs/blob/main/packages/swc-plugin/tests/__snapshots__/issue-3362.test.ts.snap (kinda looks exactly the same as the fixture except for the downtranspilation piece).

When I run with RUST_BACKTRACE=full the stack trace doesn't look very useful:

thread '<unnamed>' panicked at 'index out of bounds: the len is 1 but the index is 1', /Users/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/swc_common-0.29.10/src/syntax_pos/hygiene.rs:580:34
stack backtrace:
   0:        0x11fd42cd7 - _napi_register_module_v1
   1:        0x11fa1621a - <unknown>
   2:        0x11fd1639c - _napi_register_module_v1
   3:        0x11fd4370b - _napi_register_module_v1
   4:        0x11fd43f52 - _napi_register_module_v1
   5:        0x11fd43a44 - _napi_register_module_v1
   6:        0x11fd439a8 - _napi_register_module_v1
   7:        0x11fd43972 - _napi_register_module_v1
   8:        0x12104fa03 - _wasmer_vm_raise_trap
   9:        0x12104fa76 - _wasmer_vm_raise_trap
  10:        0x12071e7a6 - _napi_register_module_v1
  11:        0x1206b293b - _napi_register_module_v1
  12:        0x12071994c - _napi_register_module_v1
  13:        0x11fecb93b - _napi_register_module_v1
  14:        0x11fe788de - _napi_register_module_v1
  15:        0x11f8cc732 - <unknown>
  16:        0x10f7da46a - _worker
  17:     0x7ff80f16d4e1 - __pthread_start
 FAIL  packages/swc-plugin/tests/issue-3362.test.ts
  ✕ github issue #3362 (30 ms)

  ● github issue #3362

    failed to handle: index out of bounds: the len is 1 but the index is 1

      Stack backtrace:
         0: _napi_register_module_v1
         1: _wasmer_vm_raise_trap
         2: <unknown>
         3: _worker
         4: __pthread_start

Hope that helps. Also this is the only test that failed and the other tests seem ok, so this might be some edge case.

The code snippet that @mizi-lin posted seems a lot simpler and also crapped out?

[aelbore]

I got this error also

[kdy1]

Does it work on v1.3.5 and v1.3.4?

[kdy1]

@IWANABETHATGUY I think #6019 is the cause, thoughts?
There's no PR touches it other than #6019

[kdy1]

@aelbore Can you try 1.3.4 and 1.3.5?

[aelbore]

@kdy1 works on <=1.3.6
heres the minimal reproduction

import { transformSync, plugins } from '@swc/core'
import { Visitor } from '@swc/core/Visitor.js'

const content = `
  const store = () => {
  
  }

  export default store;
`

class MyPlugin extends Visitor {
  visitModule(e) {
    return e;
  }
}

const myPlugin = () => {
  return (p) => new MyPlugin().visitProgram(p)
}

const { code } = transformSync(content, {
  filename: 'abc.ts',
  jsc: {
    parser: {
      syntax: 'typescript',
      tsx: true
    }
  },
  plugin: plugins([
    myPlugin()
  ])
})

console.log(code)

[aelbore]

if you change the content to this

const content = `
  export default () => {
  
  } 
 `

it works

[kdy1]

So #6118 is the cause.
But seems like @longlho has a different issue from this.
@longlho Can you try v1.3.6?

[IWANABETHATGUY]

I expected this will not cause issues, i will try to revert the code and see if we could fix this issue.

[kdy1]

Oh, nevermind. Your plugin was based on js, so it was an identical issue.
@IWANABETHATGUY That was not the cause, sorry

[IWANABETHATGUY]

Oh, nevermind. Your plugin was based on js, so it was an identical issue. @IWANABETHATGUY That was not the cause, sorry

That's fine, hhhh

[aelbore]

another thing, empty plugin cause error also

plugin: plugins([])

[kdy1]

For formatjs, please use https://github.com/kwonoj/swc-plugin-formatjs instead

[aelbore]

Just want to ask if theres any plan to fix this? though version <=1.3.6 works Many thanks

[longlho]

For formatjs, please use kwonoj/swc-plugin-formatjs instead

that's not maintained but us btw

[kdy1]

@aelbore Not sure. Fix would be trivial but I don't want to use my time for this

[aelbore]

Thanks no worries for now i will use version <= 1.3.6 👍

[aelbore]

Just to add also

this cause the error

import {  display  } from './display'


const randomId = () => { 
  return display()
}

export { display }
export { randomId }

Solution

import {  display  } from './display'

export const randomId = () => { 
  return display()
}

export { display } from './display' 

[kdy1]

I'm not going to fix this by myself as fixing this encourages wrong usage

[kdy1]

I didn't close it because I would accept PR

[bxt]

So what is actually the issue here? I'm seeing the "index out of bounds" in my build and came here to find a fix or at least a workaround. I read "this encourages wrong usage", so I would like to know what I'm doing wrong. I also read "Fix would be trivial" so I assume a root cause is found, but I don't see it, is is the default exports? How would a PR to fix this look like?

[vjpr]

I'm encountering the same issue. I don't understand the wrong usage...

---

EDIT

I was having same issue here: #6255 (comment)

Crash

import foo from 'foo'
export {foo}

Fix

export {foo} from 'foo'

Is this syntax not valid in TS?

An error would be nice indeed.

[RexSkz]

For anyone still encountering the issue: it may not be the issue from @swc/core itself; it may be due to the plugins.

I tried the 1.3.58 version of @swc/core, and there is no export {xxx}; in my project, but I still got the "index out of bounds" message. But when I pasted my code to the SWC playground, it worked well. There's also no issue when I use 1.3.7 version in the playground.

Then I removed all plugins in my project and found it worked... After several tries, I found that both options.plugin and options.jsc.experimental.plugins can cause this issue.

I'm not familiar with Rust so I didn't find the root cause, but removing all SWC plugins is an acceptable solution for me.

[CanadaHonk]

I get this with a blank plugin in JS just extending Visitor (class MyPlugin extends Visitor { }). How does this "encourage wrong usage"? The only way to not cause this error (on my machine) is to not use any JS plugins.

[guiled]

So, I comment as well to say that I have a similar error with this parsed code

myGlob = function () {
    let a = 42;
};
myGlob();

I can't remove the plugins because I use them to transform code for a specific parser. I don't know rust as well in order to make a PR.
Is the wrong usage mentioned before the fact that we use JS plugins instead of rs plugins ?

[rene-leanix]

I also encountered this now with completely unrelated code to be transformed (see #7570) and the use of a plugin that merely returns the module/program. In my case, it's not possible to adjust the code, as that's provided by third parties.

I'm not going to fix this by myself as fixing this encourages wrong usage

@kdy1, would you mind elaborating why the wrong usage is in this case? The use of the plugin hook?

As the removal of the plugin fixes the issue in all instances, it means that the issue lies with calling the transform function with an swc-generated AST for those code snippets.

In other words,

const module = parseSync('fn((obj) => obj?.method());');
transformSync(module);

fails, but

transformSync('fn((obj) => obj?.method());');

succeeds.

Shouldn't this be fixed?

[kdy1]

@rene-leanix transform(Module) will also be removed when we can make a breaking change.

[CanadaHonk]

I have this issue when just using transform(string), when using a blank JS plugin.

[kdy1]

JS plugins will be removed in v2, and it's deprecated.

[rene-leanix]

Thanks for the quick response and clarification, @kdy1! Is there any place I can read up about the major (especially breaking) changes planned for v2?

If JS plugins are removed, could there be a way to register a (published or local) Rust plugin from within the JS code for a particular transformation?

[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.