fix(1632): erase const enums after inlining

[a-tarasyuk]

Fixes #1632

[jakebailey]

I commented on the diff (I usually only look at those), but this is the problematic transform I was pointing out.

I suspect this comes down to the emit for if/else/similar needing to ensure that bodies are still printed out if missing?

[a-tarasyuk]

@jakebailey I’m currently investigating this case

[a-tarasyuk]

It seems EmbeddedStatement doesn’t treat NotEmittedStatement as an empty statement the way Strada does.

https://github.com/microsoft/TypeScript/blob/7956c00166df552a1d6da6c2f996b558e5dd94ff/src/compiler/factory/nodeFactory.ts#L3928-L3929

https://github.com/microsoft/TypeScript/blob/7956c00166df552a1d6da6c2f996b558e5dd94ff/src/compiler/factory/nodeFactory.ts#L7163-L7167

As a result, when updating a statement (for example, an if), a NotEmittedStatement is returned and the ; is skipped.

typescript-go/internal/printer/printer.go

Lines 3895 to 3899 in 52f2ee4

	if node.Kind == ast.KindEmptyStatement {
	p.emitEmptyStatement(node.AsEmptyStatement(), true /*isEmbeddedStatement*/)
	} else {
	p.emitStatement(node)
	}

[jakebailey]

So, does that mean the fix should be elsewhere?

[jakebailey]

I'm sort of surprised by this, given I thought the default was to do this already...

[a-tarasyuk]

It looks like it doesn’t by default

typescript-go/internal/ast/visitor.go

Lines 74 to 84 in 52f2ee4

	func (v *NodeVisitor) VisitEmbeddedStatement(node *Statement) *Statement {
	if node == nil || v.Visit == nil {
	return node
	}
	if v.Visit != nil {
	return v.liftToBlock(v.Visit(node))
	}
	return node
	}

typescript-go/internal/ast/visitor.go

Lines 201 to 209 in 52f2ee4

	func (v *NodeVisitor) visitEmbeddedStatement(node *Node) *Node {
	if v.Hooks.VisitEmbeddedStatement != nil {
	return v.Hooks.VisitEmbeddedStatement(node, v)
	}
	if v.Hooks.VisitNode != nil {
	return v.liftToBlock(v.Hooks.VisitNode(node, v))
	}
	return v.VisitEmbeddedStatement(node)
	}

I’m not convinced the visitor is the right place for this - WDYT? Also, the change can be implemented via a transformer-level hook or in the emitter.