Diagnosing "Something is wrong with your metadata at position NaN and line 1"

[wgoldie]

interactive-shader-format-js/src/MetadataExtractor.js

Line 18 in 7f84e3a

const position = parseInt(tokens[tokens.length - 1], 10);

This function doesn't appear to be portable - the error message that JSON.parse spits out isn't standardized.

In Chromium I get "Unexpected token a in JSON at position 175" which results in the correct behavior.

In Firefox I get "JSON.parse: expected double-quoted property name at line 37 column 30 of the JSON data". Here the attempt to extract the position fails.

[msfeldstein]

looks like we just need to update the pattern matching? I can look at this over the weekend probably, happy to accept pull requests as well

[wgoldie]

The issue is that JSON.parse can throw a SyntaxError with an arbitrary message. Different browsers/environments will have different error messages. I see a couple of options:

1. We can try to identify the messages of different browser/runtime vendors and match against them, and fail gracefully otherwise. Unfortunately it seems that the useful SyntaxError.prototype.lineNumber property is not implemented by anyone besides Firefox (according to MDN)

2. We could also use a library for JSON parsing that will reliably emit error locations. jsonlint seems like a good lightweight option.

Happy to write a PR on either of these tomorrow or over the weekend but I'm not sure which is better from your perspective.

[msfeldstein]

The library doesn't look huge maybe that's the best bet. Would be nice to have reliable parsing. Since you're working on the site I leave the choice to you.

…

On Thu, Nov 1, 2018 at 10:41 PM Will Goldie ***@***.***> wrote: The issue is that JSON.parse can throw a SyntaxError with an arbitrary message. Different browsers/environments will have different error messages. I see a couple of options: 1. We can try to identify the messages of different browser/runtime vendors and match against them, and fail gracefully otherwise. Unfortunately it seems that the useful SyntaxError.prototype.lineNumber property is not implemented by anyone besides Firefox (according to MDN <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SyntaxError> ) 2. We could also use a library for JSON parsing that will reliably emit error locations. jsonlint <https://github.com/zaach/jsonlint> seems like a good lightweight option. Happy to write a PR on either of these tomorrow or over the weekend but I'm not sure which is better from your perspective. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#17 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAJ1b9dqh75h37qL7fH_ppdQ5Oyni-ecks5uq9sEgaJpZM4YFsSQ> .