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"Cannot read property 'type' of undefined" after upgrading to 4.14.0

See original GitHub issue

Got the error after upgrading to 4.14.0 on Flow type definitions

TypeError: Cannot read property 'type' of undefined

TypeError: Cannot read property 'type' of undefined
    at isForInRef (..\node_modules\eslint\lib\rules\no-unused-vars.js:410:24)
    at variable.references.some.ref (..\node_modules\eslint\lib\rules\no-unused-vars.js:447:21)
    at Array.some (<anonymous>)
    at isUsedVariable (..\node_modules\eslint\lib\rules\no-unused-vars.js:446:40)
    at collectUnusedVariables (..\node_modules\eslint\lib\rules\no-unused-vars.js:569:26)
    at collectUnusedVariables (..\node_modules\eslint\lib\rules\no-unused-vars.js:576:17)
    at Program:exit (..\node_modules\eslint\lib\rules\no-unused-vars.js:621:36)
    at listeners.(anonymous function).forEach.listener (..\node_modules\eslint\lib\util\safe-emitter.js:47:58)
    at Array.forEach (<anonymous>)
    at Object.emit (..\node_modules\eslint\lib\util\safe-emitter.js:47:38)
    at NodeEventGenerator.applySelector (..\node_modules\eslint\lib\util\node-event-generator.js:251:26)
    at NodeEventGenerator.applySelectors (..\node_modules\eslint\lib\util\node-event-generator.js:280:22)
    at NodeEventGenerator.leaveNode (..\node_modules\eslint\lib\util\node-event-generator.js:303:14)
    at CodePathAnalyzer.leaveNode (..\node_modules\eslint\lib\code-path-analysis\code-path-analyzer.js:630:23)
    at CodePathAnalyzer.overrideLeaveNode (..\node_modules\eslint-plugin-node\lib\rules\process-exit-as-throw.js:127:27)
    at Traverser.leave [as _leave] (..\node_modules\eslint\lib\linter.js:1000:32)
Process finished with exit code -1

Issue Analytics

State:
Created 6 years ago
Reactions:43
Comments:14 (6 by maintainers)

Top GitHub Comments

79reactions

mysticateacommented, Dec 25, 2017

I apology for the inconvenience. We have found a bug in babel-eslint’s new logic that I added. It does not work correctly if it falls back to monkeypatching once (If you are using a plugin which parses some files (e.g. imported files) with babel-eslint, it can fall back).

We have published babel-eslint@8.1.1 to fix this. Please try it.

Further reading: babel/babel-eslint#558, babel/babel-eslint#559.

14reactions

budarincommented, Dec 25, 2017

Thanks It’s solved the problem!