[Bug]: Babel crash when spreading an await inside function parameters

[Colisan]

💻

• Would you like to work on a fix?

How are you using Babel?

@babel/cli

Input code

I'm using the Babel CLI on the .js file generated by https://github.com/vuejs/devtools/blob/main/packages/shell-electron/src/backend.js once Webpack have been run. The resulting source file contains this :

  async notifyComponentUpdate(instance = null) {
    if (!this.enabled || !this.hasPermission(shared_utils_1.PluginPermission.COMPONENTS)) return;

    if (instance) {
      this.ctx.hook.emit(shared_utils_1.HookEvents.COMPONENT_UPDATED, ...(await this.backendApi.transformCall(shared_utils_1.HookEvents.COMPONENT_UPDATED, instance)));
    } else {
      this.ctx.hook.emit(shared_utils_1.HookEvents.COMPONENT_UPDATED);
    }
  }

Which crashes Babel with the following error :

Error: D:\git\devtools\packages\shell-electron\build\backend.js: Expected type "Expression" with option undefined, but instead got "SpreadElement".
    at assert (D:\git\devtools\node_modules\@babel\types\lib\asserts\generated\index.js:311:11)
    at Object.assertExpression (D:\git\devtools\node_modules\@babel\types\lib\asserts\generated\index.js:1308:3)
    at Emitter.Ep.explodeExpression (D:\git\devtools\node_modules\regenerator-transform\lib\emit.js:700:7)
    at explodeViaTempVar (D:\git\devtools\node_modules\regenerator-transform\lib\emit.js:743:23)
    at D:\git\devtools\node_modules\regenerator-transform\lib\emit.js:815:18
    at Array.map (<anonymous>)
    at Emitter.Ep.explodeExpression (D:\git\devtools\node_modules\regenerator-transform\lib\emit.js:814:28)
    at Emitter.Ep.explodeStatement (D:\git\devtools\node_modules\regenerator-transform\lib\emit.js:340:12)
    at D:\git\devtools\node_modules\regenerator-transform\lib\emit.js:323:12
    at Array.forEach (<anonymous>) {
  code: 'BABEL_TRANSFORM_ERROR'
}

When I modify emit.js to log the expr variable, I have :

Node {
  type: 'SpreadElement',
  start: 12927,
  end: 13022,
  loc: SourceLocation {
    start: Position { line: 526, column: 70, index: 12927 },
    end: Position { line: 526, column: 165, index: 13022 },
    filename: undefined,
    identifierName: undefined
  },
  argument: {
    type: 'YieldExpression',
    argument: Node {
      type: 'CallExpression',
      start: 12937,
      end: 13021,
      loc: [SourceLocation],
      callee: [Node],
      arguments: [Array],
      leadingComments: undefined,
      innerComments: undefined,
      trailingComments: undefined
    },
    delegate: false,
    trailingComments: [],
    leadingComments: [],
    innerComments: []
  },
  leadingComments: undefined,
  innerComments: undefined,
  trailingComments: undefined
}

Configuration file name

No response

Configuration

The commang I run is simply :

npx babel ./shell-electron/build/backend.js -o ./shell-electron/build/backend-babel.js --presets=@babel/preset-env

Current and expected behavior

Babel CLI crashes and don't output the new file. But when I change the js to :

  async notifyComponentUpdate(instance = null) {
    if (!this.enabled || !this.hasPermission(shared_utils_1.PluginPermission.COMPONENTS)) return;

    if (instance) {
      let t = await this.backendApi.transformCall(shared_utils_1.HookEvents.COMPONENT_UPDATED, instance);
      this.ctx.hook.emit(shared_utils_1.HookEvents.COMPONENT_UPDATED, ...t);
    } else {
      this.ctx.hook.emit(shared_utils_1.HookEvents.COMPONENT_UPDATED);
    }
  }

It don't crash anymore. Modifying the outputted file by hand is not a production-proof workflow though, and it'd be better if Babel could be run on it naturally.

Environment

npx envinfo --preset babel

  System:
    OS: Windows 10 10.0.19044
  Binaries:
    Node: 16.13.2 - C:\Program Files\nodejs\node.EXE
    Yarn: 1.22.17 - ~\AppData\Roaming\npm\yarn.CMD
    npm: 8.1.2 - C:\Program Files\nodejs\npm.CMD

Possible solution

No response

Additional context

No response

[JLHwung]

Duplicate of #12690.

It is an upstream issue tracked in facebook/regenerator#397

[babel-bot]

Hey @Colisan! We really appreciate you taking the time to report an issue. The collaborators on this project attempt to help as many people as possible, but we're a limited number of volunteers, so it's possible this won't be addressed swiftly.

If you need any help, or just have general Babel or JavaScript questions, we have a vibrant Slack community that typically always has someone willing to help. You can sign-up here for an invite.