Test parse errors in intern do not include the line that describes the error

Question

tl;dr When there is an error with a test written in intern I don't seem to get error messages that describe on which line the error occurred. I've found a workaround but its not really the ideal solution as it involves messing with code in dependent projects. Does any one have a better way / am I just doing it wrong? Thanks!

Details : I've seen several times that when there is an issue with parsing a test written in intern (for example failing to close brackets, quotes etc.) that the actual line where the error occurred is not reported, and there is only an error like this (I've subbed in for the actual path as its a work project, but you get the gist):

SyntaxError: Unexpected identifier at Function.vm.runInThisContext (<myproject>/node_modules/intern/node_modules/istanbul/lib/hook.js:163:16) at <myproject>/node_modules/intern/node_modules/dojo/dojo.js:745:8 at fs.js:266:14 at Object.oncomplete (fs.js:107:15)

I poked around a little and discovered that there's an undocumented(? - its not in here) parameter for vm.runInThisContext, which if enabled actually provides details of the original error (here and here) - there's some discussion about how this will play out but if I switch dojo.js and hook.js in istanbul (if its running) to use this parameter, I get error messages like this :

<myproject>/test/publisherConfigSpec.js:16 errorCb cat = dfd.rejectOnError(function(error) { ^^^ SyntaxError: Unexpected identifier at Function.vm.runInThisContext (<myproject>/node_modules/intern/node_modules/istanbul/lib/hook.js:163:16) at <myproject>/node_modules/intern/node_modules/dojo/dojo.js:745:8 at fs.js:266:14 at Object.oncomplete (fs.js:107:15)

which is the output I want (or at least massively improves my chances of finding and fixing the error) but its not ideal to be messing about with the node dependencies, and it seems to me that it may be too much in flux for a pull request (see most recent update to the API) Is there an alternative way of getting useful output when there's an error parsing the test code input?

Thanks for any advice :)

Answer 1

The output that Node.js provides for SyntaxError is obviously not great, but we probably won’t use undocumented features (they’re undocumented for a reason!) in any official release of Intern to make it work differently. Non-syntax errors (runtime errors) will be caught and reported competently by Intern to whatever reporters you are using.

In this case, I’d advise you to use an editor that includes support for syntax checking: Komodo Edit/IDE, WebStorm, SublimeText, Eclipse, vim… if you get to the point where you are trying to run syntactically invalid code, your code editor is failing you by not telling you soon enough that you’ve made a mistake.