Uncaught exceptions in lib/jsdoc-helpers.js about jscs-jsdoc

[qfox]

@ronkorving Thanks again for contributing! Can you please provide a part of your jsdoc?

[qfox]

I think it's a bug inside code scan loop. For @returns type checking or something.
I wish to have a part of your code ;-)

[ronkorving]

It's definitely part of the "checkReturnTypes" check (turning that to false "fixes" the issue). Unfortunately, the project's code is not open source :( So I hope I can track down the origin of the issue myself. When I log the cases where these errors happen, I do get a lot of output, so it's kinda "all over the place". Any advice?

[qfox]

@ronkorving Thanks. Actually, there's a little hacky code scan algorithm. If you have some ideas about it please share it.
Btw, to repeat this bug I just need one function that causes an error, so no need to share all the code. Anyway thanks. Even it's not possible.

[qfox]

@ronkorving Look at ./lib/jsdoc-helpers.js file. At jsDocSimplifyNode and jsDocMatchType functions.
https://github.com/zxqfox/jscs-jsdoc/blob/master/lib/jsdoc-helpers.js#L59

[ronkorving]

I found one!

 * @returns {null}

That caused:

TypeError: Cannot read property 'type' of null
    at Object.jsDocMatchType [as match] (/home/rk/mage/node_modules/jscs-jsdoc/lib/jsdoc-helpers.js:135:32)
    at module.exports.check (/home/rk/mage/node_modules/jscs-jsdoc/lib/rules/validate-jsdoc.js:172:39)
    at Array.forEach (native)
    at Array.validateReturnsLine [as 1] (/home/rk/mage/node_modules/jscs-jsdoc/lib/rules/validate-jsdoc.js:171:43)
    at /home/rk/mage/node_modules/jscs-jsdoc/lib/rules/validate-jsdoc.js:67:38
    at Array.forEach (native)
    at Object.JsFile.iterateNodesByType (/home/rk/mage/node_modules/jscs/lib/js-file.js:112:42)
    at Object.module.exports.check (/home/rk/mage/node_modules/jscs-jsdoc/lib/rules/validate-jsdoc.js:39:14)
    at StringChecker.checkString (/home/rk/mage/node_modules/jscs/lib/string-checker.js:219:22)
    at Array.forEach (native)

The function is this:

exports.shard = function () {
    return null;
};

[qfox]

@ronkorving Do you want to fix it by self? ;-) I can do it.

[ronkorving]

I have no idea about Esprima objects, so I don't really understand the problem to be honest (besides "it breaks and I can work around it"). If you can resolve this the proper way, I would be very grateful. Before you publish another release however, I will also try and track down that other error.

[qfox]

@ronkorving almost done ;-)

[ronkorving]

Ah, the other error was triggered by exactly the same line of JSDoc!

[ronkorving]

And here is its stack trace:

TypeError: Cannot read property 'type' of null
    at Object.jsDocMatchType [as match] (/home/rk/mage/node_modules/jscs-jsdoc/lib/jsdoc-helpers.js:135:32)
    at module.exports.check (/home/rk/mage/node_modules/jscs-jsdoc/lib/rules/validate-jsdoc.js:172:39)
    at Array.forEach (native)
    at Array.validateReturnsLine [as 1] (/home/rk/mage/node_modules/jscs-jsdoc/lib/rules/validate-jsdoc.js:171:43)
    at /home/rk/mage/node_modules/jscs-jsdoc/lib/rules/validate-jsdoc.js:67:38
    at Array.forEach (native)
    at Object.JsFile.iterateNodesByType (/home/rk/mage/node_modules/jscs/lib/js-file.js:112:42)
    at Object.module.exports.check (/home/rk/mage/node_modules/jscs-jsdoc/lib/rules/validate-jsdoc.js:39:14)
    at StringChecker.checkString (/home/rk/mage/node_modules/jscs/lib/string-checker.js:219:22)
    at Array.forEach (native)

[qfox]

@ronkorving Thanks, fixing it.
Btw, esprima objects are the same objects used by SpiderMonkey Parser API: https://developer.mozilla.org/en-US/docs/SpiderMonkey/Parser_API

[qfox]

@ronkorving Thanks again. It should works now.

[ronkorving]

Awesome! Thank you! I wasn't even sure anymore if {null} and {undefined} were legal or not.

[ronkorving]

Just tested it, and it no longer breaks, thanks!

[qfox]

@ronkorving Now it's legal ;-)