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babel 7.1.5 won't compile with retainLines: true and plugin-proposal-object-rest-spread #8992

hibikiledo opened this Issue Nov 8, 2018 · 3 comments


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hibikiledo commented Nov 8, 2018

Bug Report

Current Behavior

TypeError: Cannot read property 'start' of undefined
    at Generator.ArrowFunctionExpression (/Users/hibikiledo/Desktop/babel-generator-7.1.5-bug/node_modules/@babel/generator/lib/generators/methods.js:136:72)
    at withSource (/Users/hibikiledo/Desktop/babel-generator-7.1.5-bug/node_modules/@babel/generator/lib/printer.js:299:22)
    at Buffer.withSource (/Users/hibikiledo/Desktop/babel-generator-7.1.5-bug/node_modules/@babel/generator/lib/buffer.js:185:28)
    at Generator.withSource (/Users/hibikiledo/Desktop/babel-generator-7.1.5-bug/node_modules/@babel/generator/lib/printer.js:178:15)
    at Generator.print (/Users/hibikiledo/Desktop/babel-generator-7.1.5-bug/node_modules/@babel/generator/lib/printer.js:298:10)
    at Generator.printJoin (/Users/hibikiledo/Desktop/babel-generator-7.1.5-bug/node_modules/@babel/generator/lib/printer.js:362:12)
    at Generator.printList (/Users/hibikiledo/Desktop/babel-generator-7.1.5-bug/node_modules/@babel/generator/lib/printer.js:422:17)
    at Generator.CallExpression (/Users/hibikiledo/Desktop/babel-generator-7.1.5-bug/node_modules/@babel/generator/lib/generators/expressions.js:181:8)
    at withSource (/Users/hibikiledo/Desktop/babel-generator-7.1.5-bug/node_modules/@babel/generator/lib/printer.js:299:22)
    at Buffer.withSource (/Users/hibikiledo/Desktop/babel-generator-7.1.5-bug/node_modules/@babel/generator/lib/buffer.js:185:28)

Input Code
Please see

Expected behavior/code
Babel should compile input code without throwing an error.

Babel Configuration (.babelrc, package.json, cli command)

  "env": {
    "development": {
      "retainLines": true,
      "plugins": [


  • Babel version(s): 7.1.5
  • Node/npm version: Node 8.12.0
  • OS: OSX 10.13.6
  • Monorepo: no
  • How you are using Babel: cli

Possible Solution
Remove retainLines seems to fix the problem.

Additional context/Screenshots


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babel-bot commented Nov 8, 2018

Hey @hibikiledo! 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.


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loganfsmyth commented Nov 9, 2018

Thanks, I posted a fix: #9003

Do you mind if I ask why you're using retainLines? We've often considered removing it.


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hibikiledo commented Nov 9, 2018

I don't know why it is there in the first place. I checked the commit message and still had no clue.

I ended up removing it permanently since I already had source maps enabled.

Thanks for the fix anyway 🥇

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