Debugging using breakpoints not working -- missing source map urls?

[atorma]

I am running Mocha tests of Streamlined code (fibers) in IntelliJ IDEA and Node 6.9. Debugging the code using breakpoints is not working. Either the IDE stops at a wrong line or does not stop at all.

I can see source map files are created in the .streamline cache directory. I tried adding a source map url to one of the generated _js files. That got breakpoints working. Should code generation add source map urls in the files?

[bjouhier]

@atorma I ran some tests and I see the // #sourceMappingURL=... directive at the end of the generated source when the --source-maps option is true or inline. Which options are you using?

[atorma]

I was using IntelliJ IDEA's Mocha run configuration in Windows 10. It executed

C:\Tools\nodejs\node.exe --debug-brk=63761 --expose_debug_as=v8debug C:\Path\to\my\project\node_modules\mocha\bin\_mocha --timeout 0 --ui bdd --reporter C:\Users\MyName\.IntelliJIdea2017.2\config\plugins\NodeJS\js\mocha-intellij\lib\mochaIntellijReporter.js app\test\**\*Test.*js

My mocha.opts were

--recursive
--require app/test/mocha-init
--compilers _js:streamline/register
--colors

However, I got debugging with breakpoints to work when I created a module "register-streamline.js" like this

'use strict';

require('streamline').register({
    runtime: 'fibers',
    quiet: true,
    sourceMaps: 'inline'
});

and then used that as a compiler for *._js in mocha.opts:

--recursive
--require app/test/mocha-init
--compilers _js:app/test/register-streamline
--colors

However, I still don't see the // #sourceMappingURL=... in the cached files in C:\Users\MyName\.streamline.

I haven't tried pre-compiling with babel-plugin-streamline. Running using _node is difficult to get working with Mocha run configs in IDEA (at least in Windows), so I gave up on that.

[atorma]

Okay, sourceMappingURLs are generated when pre-compiling sources using babel. However, as the readme says, "The recommandation is to use the loader during development" and "The fibers mode gives superior development experience". I agree and would like to stick to that :)

Is there a reason why sourceMappingURLs are not generated in the cached files?

[bjouhier]

You could also set the options via a .streamline.json file (either in your project directory or your user's home directory). This is a bit simpler than creating a register-streamline.js script.

The sourceMappingURL directives are not included in the cached files but they are added dynamically after the source is retrieved from the cache. I don't remember the whole rationale but I think it was done this way to keep the cache independent from the source-map options.

[atorma]

With option sourceMaps: true Mocha tests simply crashed in the IDE when running in debug mode (normal mode was fine). That happened both with a streamline.json file and with a registration script.