fix await and yield for do expression

[tanhauhau]

Q	A
Fixed Issues?	Fixes #3780
Patch: Bug Fix?
Major: Breaking Change?
Minor: New Feature?
Tests Added + Pass?	Yes
Documentation PR Link
Any Dependency Changes?
License	MIT

[babel-bot]

Build successful! You can test your changes in the REPL here: https://babeljs.io/repl/build/10961/

[babel-bot]

Build successful! You can test your changes in the REPL here: https://babeljs.io/repl/build/10918/

[nicolo-ribaudo]

You can/should use hasType instead:

babel/packages/babel-plugin-transform-block-scoping/src/index.js

Lines 572 to 576 in f92c2ae

	const hasAsync = traverse.hasType(
	fn.body,
	"AwaitExpression",
	t.FUNCTION_TYPES,
	);

[nicolo-ribaudo]

Disclaimer: I didn't know about that method until 5 mins ago. Usually, when someone adds a new method to @babel/traverse there is a 50% probability that it already exists.

[tanhauhau]

I tried to look for it too... But I guess you can find things better than me

[nicolo-ribaudo]

Can you disable the failing test on node 6, since it doesn't support async functions?

Example:

babel/packages/babel-plugin-transform-new-target/test/fixtures/exec/reflect-class/options.json

Lines 1 to 3 in eac4c5b

	{
	"minNodeVersion": "6.0.0"
	}

[nicolo-ribaudo]

Sorry for the bad example, the min node version should be 8 😅

[tanhauhau]

Oh wait what was I thinking.. haha

[tanhauhau]

@nicolo-ribaudo I'm thinking might as well fix for yield generators as well

[nicolo-ribaudo]

I'd prefer it do be done in a separate PR, since there are many more edge cases (e.g. manually calling .throw or .return, and how try/finally with nested do expression behave).

[tanhauhau]

@nicolo-ribaudo fixed the PR