v4.0.0 doesn't give file/line for wrong syntax.

[bobef]

I'm happily moving some of my stuff to ES6 but when I wrong the syntax I get SyntaxError which goes to my on( 'unhandledException' ) and I print it to get message like this. Not very helpful.

SyntaxError: Unexpected identifier
    at exports.runInThisContext (vm.js:53:16)
    at Module._compile (module.js:413:25)
    at Object.Module._extensions..js (module.js:452:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Module.require (module.js:365:17)
    at require (module.js:384:17)
    at Object.<anonymous> (/Users/bobi/Dev/prototype-js/tests/tests.js:11:1)
    at Module._compile (module.js:434:26)
    at Object.Module._extensions..js (module.js:452:10)

[dodev]

You can start your investigation by examining what's on line 11 in /Users/bobi/Dev/prototype-js/tests/tests.js

[bobef]

I did and my investigation led to the conclusion that SyntaxError doesn't contain file/line information, so I posted here. Line 11 is console.error( e.stack ), and e is the exception from on( 'unhandledException' ). And e.lineNumber and the others described in MDN are undefined.

[dodev]

Try removing the unhandled exception callback. I think, if it's a syntax error, you'll get a cleaner stack trace, because the interpreter will break on the exact line and column, where the unexpected identifier was met.

[Trott]

Can you put the first 15 or so lines of /Users/bobi/Dev/prototype-js/tests/tests.js in a gist and link to it here?

[bobef]

You can see the whole file if you like. https://github.com/Perennials/prototype-js/blob/master/tests/tests.js

[bobef]

I will give way to reproduce later when I get to the office.

[bobef]

So here is how to reproduce:

mkdir dir
cd dir
npm install https://github.com/Perennials/prototype-js/tarball/master
cd node_modules/Prototype
npm install
### Break the syntax somewhere. Edit tests/Function.js:120 and change it to "iface1_decl {}"
npm test

And the line that prints the error is nodule_modules/Prototype/node_modules/Unitest/Unitest.js:569. And if you remove the uncaughtException handler the error is not printed for some reason.

[defunctzombie]

I too ran into this issue when trying to process a syntax error after adding an uncaughtException handler. It seems that behavior prior to v4 might have been that the syntax error information (filename and line number) were printed to stderr regardless of the uncaughtException handler (the exception still given to the handler tho).

I don't see a way to get the fileName or lineNumber information from the error. Using toString() simply results in the message SyntaxError: Unexpected identifier.

Seems that behavior might be slightly different with these errors on startup versus before.

[defunctzombie]

Any updates on this? It makes it rather multi-step (annoying) to debug syntax error when using tools like node-dev or even with your own uncaughtException handlers. This might not be obvious to users.

/cc @bnoordhuis @rvagg @mikeal

[Fishrock123]

cc @nodejs/collaborators could we get more eyes on this?

[Qard]

This is present in v3 too.

Also, the line number in the stack trace is like that in all versions of node. What's wrong is that the extra context info lines are missing.

v3/v4:

> Prototype@1.6.0 test /node_modules/Prototype
> node ./tests/tests.js

SyntaxError: Unexpected token {
    at exports.runInThisContext (vm.js:53:16)
    at Module._compile (module.js:413:25)
    at Object.Module._extensions..js (module.js:448:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Module.require (module.js:365:17)
    at require (module.js:384:17)
    at Object.<anonymous> (/node_modules/Prototype/tests/tests.js:11:1)
    at Module._compile (module.js:430:26)
    at Object.Module._extensions..js (module.js:448:10)

others:

> Prototype@1.6.0 test /node_modules/Prototype
> node ./tests/tests.js

/node_modules/Prototype/tests/Function.js:120
        iface1_decl {}
                    ^
SyntaxError: Unexpected token {
    at exports.runInThisContext (vm.js:53:16)
    at Module._compile (module.js:413:25)
    at Object.Module._extensions..js (module.js:448:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Module.require (module.js:365:17)
    at require (module.js:384:17)
    at Object.<anonymous> (/node_modules/Prototype/tests/tests.js:11:1)
    at Module._compile (module.js:430:26)
    at Object.Module._extensions..js (module.js:448:10)

Notice the bit with the ^ in it. Probably something changed in V8. Not sure if there's anything we can do about it, but I'll let some others have a look.

[domenic]

This is probably a result of the change in #2108. Strange, I thought we had tests for this...

[defunctzombie]

Is this going to be considered a regression?