[async] Cannot read property 'members' of undefined

[nippur72]

when compiling this code for ES5 (not ES6)

async function f() {
 return { }; 
}

instead of giving the "only available in ES6" warning, it throws this exception:

 throw e;
 ^
TypeError: Cannot read property 'members' of undefined
 at resolveDeclaredMembers (C:\Users\Nino\AppData\Roaming\npm\node_modules\typescript\bin\tsc.js:15429:65)
 at resolveTypeReferenceMembers (C:\Users\Nino\AppData\Roaming\npm\node_modules\typescript\bin\tsc.js:15459:26)
 at resolveStructuredTypeMembers (C:\Users\Nino\AppData\Roaming\npm\node_modules\typescript\bin\tsc.js:15665:21)
 at getPropertiesOfObjectType (C:\Users\Nino\AppData\Roaming\npm\node_modules\typescript\bin\tsc.js:15673:24)
 at propertiesRelatedTo (C:\Users\Nino\AppData\Roaming\npm\node_modules\typescript\bin\tsc.js:17141:34)
 at objectTypeRelatedTo (C:\Users\Nino\AppData\Roaming\npm\node_modules\typescript\bin\tsc.js:17107:30)
 at isRelatedTo (C:\Users\Nino\AppData\Roaming\npm\node_modules\typescript\bin\tsc.js:16935:34)
 at checkTypeRelatedTo (C:\Users\Nino\AppData\Roaming\npm\node_modules\typescript\bin\tsc.js:16824:26)
 at checkTypeAssignableTo (C:\Users\Nino\AppData\Roaming\npm\node_modules\typescript\bin\tsc.js:16797:20)
 at isTypeAssignableTo (C:\Users\Nino\AppData\Roaming\npm\node_modules\typescript\bin\tsc.js:16791:20)

using tsc 1.5.3

[rbuckton]

nino-porcino (@nippur72): TypeScript 1.5.3 does not contain support for Async Functions, and I cannot seem to repro this in master. It's possible a recent unrelated change may have fixed this. Is it possible you were using a different version of the compiler than the one you mentioned above? Can you verify the version of the compiler you are using, or possibly verify this against a recent nightly build?

[mhegazy]

nino-porcino (@nippur72) can you try using latest `typescript@next?

[nippur72]

Mohamed Hegazy (@mhegazy) Ron Buckton (@rbuckton) I've checked with typescript@next and the bug is gone, so I'm closing this.

(P.S. I was sure it was 1.5.3, but as you've said it couldn't be, so more likely I had something greater than 1.5.3).

[mhegazy]

thanks nino-porcino (@nippur72) for confirming.

[jsen-]

I think the issue is not yet gone.

I'm using typescript 1.6.0-dev.20150819 with experimentalAsyncFunctions enabled, targetting es6

The following code seems to trigger the error:

async function abcd() {
 console.log('abcd');
}
abcd().then(() => {
 console.log('then');
});

or

async function abcd() {
 console.log('abcd');
}
async function runAbcd() {
 await abcd();
}
runAbcd();

The following compiles (unfortunately there's no awaiting mechanism):

async function abcd() {
 console.log('abcd');
}
abcd();

D:\projects\sach\node_modules\electrolyte\node_modules\typescript\lib\typescript.js:35252
 throw e;
 ^

TypeError: Cannot read property 'members' of undefined
 at resolveDeclaredMembers (D:\projects\sach\node_modules\electrolyte\node_modules\typescript\lib\typescript.js:15607:65)
 at resolveTypeReferenceMembers (D:\projects\sach\node_modules\electrolyte\node_modules\typescript\lib\typescript.js:15637:26)
 at resolveStructuredTypeMembers (D:\projects\sach\node_modules\electrolyte\node_modules\typescript\lib\typescript.js:15870:21)
 at getPropertyOfType (D:\projects\sach\node_modules\electrolyte\node_modules\typescript\lib\typescript.js:16002:32)
 at checkPropertyAccessExpressionOrQualifiedName (D:\projects\sach\node_modules\electrolyte\node_modules\typescript\lib\typescript.js:19993:24)
 at checkPropertyAccessExpression (D:\projects\sach\node_modules\electrolyte\node_modules\typescript\lib\typescript.js:19978:20)
 at checkExpressionWorker (D:\projects\sach\node_modules\electrolyte\node_modules\typescript\lib\typescript.js:22117:28)
 at checkExpression (D:\projects\sach\node_modules\electrolyte\node_modules\typescript\lib\typescript.js:22068:42)
 at resolveCallExpression (D:\projects\sach\node_modules\electrolyte\node_modules\typescript\lib\typescript.js:20919:28)
 at getResolvedSignature (D:\projects\sach\node_modules\electrolyte\node_modules\typescript\lib\typescript.js:21088:47)

iojs versions:

{ http_parser: '2.5.0',
 node: '3.0.0',
 v8: '4.4.63.26',
 uv: '1.6.1',
 zlib: '1.2.8',
 ares: '1.10.1-DEV',
 modules: '45',
 openssl: '1.0.2d' }

[nippur72]

Yes the issue is back, I re-discovered it yesterday in 1.6 nightly, so I'm reopening it.