Implement JSX syntax

[nzakas]

Phase 2 is to add JSX syntax support into this parser. This would involve:

1. Converting the TypeScript JSX syntax tree into an ESTree-compatible one.
2. Convert the TypeScript tokens into Esprima-style tokens.
3. Making the result pass the JSX tests that are already tests in tests/fixtures/ecma-features/jsx.

@JamesHenry are you interested in taking a stab at this?

[JamesHenry]

Thanks a lot for mapping out those steps, yes I'll try and find some time this weekend!

[JamesHenry]

I have made some progress on this, but I have some questions on how to approach some of the conversions. What is the best way for us to chat about that? Gitter?

[JamesHenry]

There seem to be some fundamental issues in our more "interesting" jsx tests at the moment, and I have begun reporting them in the TypeScript repo:

• "embedded-tags": Support JSX Element as JSX Attribute Value microsoft/TypeScript#7410
• "namespaced attributes": JSX namespaced attribute syntax not supported microsoft/TypeScript#7411

[nzakas]

If I'm on gitter, yes, though I'd prefer such issues be documented here so we have a good record.

[JamesHenry]

Great point - if I have concrete questions I will post them here. I am going to stop now as this has ended up dominating my weekend, but I have made a lot of progress (as much as anything in my personal understanding of eslint internals, ASTs and tsc output :) ).

The current status is:

• 3 tests are unrunnable due to the issues reported to TS above
• 3 remaining non-passing tests

I'll keep you updated on my progress as and when I find time during my evenings next week!

[nzakas]

Awesome, thanks so much!

[nzakas]

If you manage to get the three failing tests working, I'd say just remove the tests that fail due to the TS issues and we can handle those as bugs.

[JamesHenry]

Just noting down this third related TS issue here for reference: microsoft/TypeScript#7471