Support type annotation for rest argument on babylon parser

[vjeux]

This is working on the flow parser but not babylon

echo 'function f(...flags: Array<boolean>) {}' | ./bin/prettier.js --stdin
function f(...flags: Array<boolean>) {}

[hzoo]

@vjeux if you have time, can you report these kinds of issues in babylon/recast as well if relevant?

[vjeux]

I'm curious, what kind of issue are you looking for? Is the fact that the AST is different an issue worth raising?

[jlongster]

To me your comment implies that the babylon parser doesn't have the typeAnnotation property on RestElement types. Is that why it doesn't work for babylon?

[jlongster]

@hzoo This probably isn't the best place to talk about this, but it's worth noting that the jest test suite does not pass with babylon. The test runner passes the useFlowParser: true option always. I think some of it is whether it's parsing a file as a module or not and some strict mode checks or something. We should see what it takes to get it running.

[vjeux]

For flow, it's in the Identifier inside of RestElement

For babylon, it's in the RestElement

[jlongster]

Aaah very interesting. Ok, thanks!