Fix _scriptDir for node.js + USE_PTHREADS + MODULARIZE

[VirtualTim]

node.js doesn't have document.currentScript.src, so use __filename instead.
Since you can have a module designed for both node and the web default to document.currentScript.src, but fall back to __filename if that fails.

[kripken]

Thanks! Nice fix.

Please add a test for this.

[VirtualTim]

I'm not really sure the best way to test this. The only node tests I can see is the one in tests/test_core.py. Perhaps it's better to make a tests/test_node.py (similar to tests/test_browser.py) and put all the node tests in there?
I have a feeling that writing a test is going to be heaps more work than implementing the fix.

[kripken]

Oh, tests/test_other.py is probably the best place for this. See for example test_node_js_run_from_different_directory which does something slightly related, I think?

But maybe I'm missing the difficulty in testing this - is it harder than cloning and modifying that test a little?

[VirtualTim]

OK, I think I got the test sorted.
I did have to compile with EXPORT_NAME, as it appears that 'Module' is already be defined in node.js.
I still think it's worth (one day) creating something like test-environment-node that contains node.js specific tests, but I think that should be a separate issue.

[kripken]

Thanks! lgtm with that one final nit.

[kripken]

there is a helper function for this, create_test_file(name, contents)

[VirtualTim]

Made the change, but I'm not sure what's going on with the tests. My test passed, but some other ones appear to have hung.

[kripken]

Yeah, weird about those tests... I can't seem to restart them.

Looks safe to land though as all the other tests passed, landing!