createTypeAnnotationBasedOnTypeof(type) throwing error when not supposed to

[gchamon]

Ran into an issue using babel with gulp, where the mentioned function was throwing the following error:

events.js:160                                   
      throw er; // Unhandled 'error' event      
      ^                                         
Error: /home/gchamon/WayCarbon/projetos/eclimas/src/app/admin/factorBuilder/libs/nerdamer.core.js: Invalid typeof value                                                                                
at Object.createTypeAnnotationBasedOnTypeof (/home/gchamon/WayCarbon/projetos/eclimas/node_modules/babel-types/lib/flow.js:106:11)                                                                 
at inferAnnotationFromBinaryExpression (/home/gchamon/WayCarbon/projetos/eclimas/node_modules/babel-traverse/lib/path/inference/inferer-reference.js:136:12)                                       
at getConditionalAnnotation (/home/gchamon/WayCarbon/projetos/eclimas/node_modules/babel-traverse/lib/path/inference/inferer-reference.js:171:18)                                                 
at getTypeAnnotationBindingConstantViolations (/home/gchamon/WayCarbon/projetos/eclimas/node_modules/babel-traverse/lib/path/inference/inferer-reference.js:45:18)                                
at NodePath.exports.default (/home/gchamon/WayCarbon/projetos/eclimas/node_modules/babel-traverse/lib/path/inference/inferer-reference.js:17:14)                                                   
at NodePath._getTypeAnnotation (/home/gchamon/WayCarbon/projetos/eclimas/node_modules/babel-traverse/lib/path/inference/index.js:64:20)                                                            
at NodePath.getTypeAnnotation (/home/gchamon/WayCarbon/projetos/eclimas/node_modules/babel-traverse/lib/path/inference/index.js:31:19)
at Identifier (/home/gchamon/WayCarbon/projetos/eclimas/node_modules/babel-plugin-minify-simplify/lib/index.js:509:18)
at NodePath._call (/home/gchamon/WayCarbon/projetos/eclimas/node_modules/babel-traverse/lib/path/context.js:76:18)
at NodePath.call (/home/gchamon/WayCarbon/projetos/eclimas/node_modules/babel-traverse/lib/path/context.js:48:17)  

upon investigation, I decided to verify what was actually inside type by modifying the function createTypeAnnotationBasedOnTypeof(type) inside flow.js, altering the error throwing line to:

throw new Error(`Invalid typeof value: '${type}' (${typeof type})`);

which now, interestingly, yelds the error:

Invalid typeof value: 'undefined ' (string)

Notice the blank space after undefined. Trying a hack to make it work, replacing " " to "" as in:

type = type.replace(" ", "");

gulp runs fine alright. What is going on?

[babel-bot]

Hey @gchamon! 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
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[nicolo-ribaudo]

Which is the code that causes babel to throw? A starting point for a proper fix would be to understand why there is that space.

[gchamon]

That goes without saying, but following the traceback we can see that the error is raised in the scope of the babel-traverse -> minify then all the way to babel-type so it is all self contained inside babel-maintained code, which means that even if I pinpointed the source of the issue I wouldn't be able to correct it myself without diverging from this repo.

Anyway, the provided "hack" works and everything minifies as expected (too well actually, I need to figure out how to make it respect angular names so it doesn't break the framework) I just wanted to know if there was another workaround that doesn't involve modifying third party code, because we don't have the resources to maintain modified code

[nicolo-ribaudo]

Can you provide an example of code which, when run trought Babel with the babel-minify preset, generates that error? "undefind " should never be passed to that function, so the bug is somewhere else. Without reproducing the error, it is impossible to know where it exactly is.

[gchamon]

I am sorry I did not update you guys on the issue. I believe the issue was with our code, some typo an ex-employee left and nobody knew what was going on. Really sorry to waste your time on it. This should be closed and, hopefully, forgotten.

[existentialism]

@gchamon thanks for the update! let us know if you run into it again!