"Unexpected linter output" error

[dcposch]

Error message:

> webtorrent-app@0.0.0 test /home/dc/webtorrent-app
> standard

standard: Unexpected linter output:

TypeError: Cannot read property 'type' of undefined
    at isRedundantSuperCall (/home/dc/webtorrent-app/node_modules/standard/node_modules/eslint/lib/rules/no-useless-constructor.js:24:38)
    at EventEmitter.checkForConstructor (/home/dc/webtorrent-app/node_modules/standard/node_modules/eslint/lib/rules/no-useless-constructor.js:52:46)
    at emitOne (events.js:82:20)
    at EventEmitter.emit (events.js:169:7)
    at NodeEventGenerator.enterNode (/home/dc/webtorrent-app/node_modules/standard/node_modules/eslint/lib/util/node-event-generator.js:42:22)
    at CodePathAnalyzer.enterNode (/home/dc/webtorrent-app/node_modules/standard/node_modules/eslint/lib/code-path-analysis/code-path-analyzer.js:591:23)
    at CommentEventGenerator.enterNode (/home/dc/webtorrent-app/node_modules/standard/node_modules/eslint/lib/util/comment-event-generator.js:98:23)
    at Controller.controller.traverse.enter (/home/dc/webtorrent-app/node_modules/standard/node_modules/eslint/lib/eslint.js:839:36)
    at Controller.__execute (/home/dc/webtorrent-app/node_modules/standard/node_modules/eslint/node_modules/estraverse/estraverse.js:397:31)
    at Controller.traverse (/home/dc/webtorrent-app/node_modules/standard/node_modules/eslint/node_modules/estraverse/estraverse.js:495:28)

If you think this is a bug in `standard`, open an issue: https://github.com/feross/standard/issues
npm ERR! Test failed.  See above for more details.

To reproduce, run npm test (or equivalently, standard) on the following code: webtorrent/webtorrent-desktop@f71343d

[dcposch]

Update: looks like this happened because I used the ES6 class keyword.

IMO standard should either support those new ES6 features, or give a more descriptive error message

[feross]

@dcposch The code that you linked to has since disappeared. Can you paste an example here? The class keyword should work without crashing eslint, I believe. So, there's probably a bug in eslint somewhere. If you paste your code, I can look at it and file any needed issues / send a pr to eslint.

[dcposch]

Found it:

class UnplayableError extends Error {
  constructor () {
    this.message = 'Can\'t play any files in torrent'
  }
}

[dcposch]

K here's a minimal way to reproduce it.

Works: (standard outputs linter errors, but doesn't crash)

class MyClass extends Error {
  constructor () {
  }
}

Works:

class MyClass {
  constructor () {
    this.n = 0
  }
}

Crashes:

class MyClass extends Error {
  constructor () {
    this.n = 0
  }
}

[feross]

This is probably an eslint bug. I opened an issue: eslint/eslint#5662

[feross]

Looks like this is fixed on eslint master. Once the version after 2.4.0 is released, we can bump it in standard.

[feross]

Bumped eslint to 2.8.0 -- closing this now.