"Lexical environment is suspended" when using visitEachChild from nightly transformer API (2.3.0-dev)

[fabiandev]

I'm experiencing issues with visitEachChild for e.g. a variable declaration when using the transformer API from the nightly builds.

TypeScript Version: 2.3.0-dev.20170414

Code

Sample code to transform:

let a: () => any;

Minimal transformer:

function transformer(context) {
    const visitor = node => {
        return ts.visitEachChild(node, visitor, context);
    };

    return sf => ts.visitNode(sf, visitor);
}

@rkirov pointed out, that a "minimal repro is input function f(a: () => null) {} with the identity transformer (i.e. just calling visitEachChild with (n) => n" (see #13940 (comment))

Expected behavior:

Should run without errors.

Actual behavior:

Error: Debug Failure. False expression: Lexical environment is suspended.

I've reproduced the error on runkit: https://runkit.com/fabiandev/58e571bd9383e400145e1245

[longlho]

Hi there is there any activity on this issue :(? Thanks!

[kimamula]

Shouldn't this be included in TypeScript 2.3.1 milestone?
I am wondering whether the stable release of TypeScript 2.3 will be shipped with the custom transformer feature.

[fabiandev]

As of build 2.3.0-dev.20170426 with #15377 merged, the example on runkit works fine: https://runkit.com/fabiandev/59005befe4d0d60011238738