Language service crash in 'displayPartKind'

[DanielRosenwasser]

In Version 2.1.0-dev.20161110

TypeError: Cannot read property 'flags' of undefined
    at displayPartKind (C:\Users\drosen\AppData\Roaming\npm\node_modules\typescript\lib\tsserver.js:51437:31)
    at symbolPart (C:\Users\drosen\AppData\Roaming\npm\node_modules\typescript\lib\tsserver.js:51435:34)
    at Object.writeSymbol (C:\Users\drosen\AppData\Roaming\npm\node_modules\typescript\lib\tsserver.js:51422:31)
    at buildBindingElementDisplay (C:\Users\drosen\AppData\Roaming\npm\node_modules\typescript\lib\tsserver.js:22476:28)
    at C:\Users\drosen\AppData\Roaming\npm\node_modules\typescript\lib\tsserver.js:22457:110
    at buildDisplayForCommaSeparatedList (C:\Users\drosen\AppData\Roaming\npm\node_modules\typescript\lib\tsserver.js:22503:21)
    at buildBindingPatternDisplay (C:\Users\drosen\AppData\Roaming\npm\node_modules\typescript\lib\tsserver.js:22457:21)
    at buildParameterDisplay (C:\Users\drosen\AppData\Roaming\npm\node_modules\typescript\lib\tsserver.js:22442:21)
    at buildDisplayForParametersAndDelimiters (C:\Users\drosen\AppData\Roaming\npm\node_modules\typescript\lib\tsserver.js:22531:21)
    at buildSignatureDisplay (C:\Users\drosen\AppData\Roaming\npm\node_modules\typescript\lib\tsserver.js:22575:17)

[ahejlsberg]

@DanielRosenwasser Repro?

[DanielRosenwasser]

@mhegazy told me to just file this and we'll discuss offline.

[nickytonline]

I'm able to produce this error by destructuring arguments two levels deep, e.g.

import * as React from 'react';

interface SomeInterface {
	someBoolean: boolean,
	someString: string;
}

interface SomeProps {
  someProp: SomeInterface;
}

export const SomeStatelessComponent = ({someProp: { someBoolean, someString}}: SomeProps) => (<div>{`${someBoolean}${someString}`}</div>);

but if I destruct just the top level, e.g. someProp, it works

export const SomeStatelessComponent = ({someProp}: SomeProps) => (<div>{`${someProp.someBoolean}${someProp.someString}`}</div>);