Error: Debug Failure. False expression. in `tryReuseStructureFromOldProgram` during `getApplicableRefactors`

[aozgaa]

tsserver version: 2.6.1
hitting sessions: 3003
stack:

Error: Debug Failure. False expression.
    at tryReuseStructureFromOldProgram (tsserver.js:59129:22)
    at Object.createProgram (tsserver.js:58930:34)
    at synchronizeHostData (tsserver.js:79707:26)
    at Object.getProgram (tsserver.js:79742:13)
    at ConfiguredProject.Project.updateGraphWorker (tsserver.js:83016:53)
    at ConfiguredProject.Project.updateGraph (tsserver.js:82966:39)
    at ConfiguredProject.updateGraph (tsserver.js:83248:53)
    at ConfiguredProject.Project.getLanguageService (tsserver.js:82702:26)
    at IOSession.Session.getApplicableRefactors (tsserver.js:86474:32)
    at Session.handlers.ts.createMapFromTemplate._a.(anonymous function) (tsserver.js:85436:61)
    at tsserver.js:86669:88
    at IOSession.Session.executeWithRequestId (tsserver.js:86660:28)
    at IOSession.Session.executeCommand (tsserver.js:86669:33)
    at IOSession.Session.onMessage (tsserver.js:86689:35)
    at Interface.<anonymous> (tsserver.js:87881:27)
    at emitOne (events.js:96:13)
    at Interface.emit (events.js:191:7)
    at Interface._onLine (readline.js:241:10)
    at Interface._normalWrite (readline.js:384:12)
    at Socket.ondata (readline.js:101:10)
    at emitOne (events.js:96:13)
    at Socket.emit (events.js:191:7)
    at readableAddChunk (_stream_readable.js:178:18)
    at Socket.Readable.push (_stream_readable.js:136:10)
    at Pipe.onread (net.js:560:20)

[mhegazy]

The Source: Telemetry have limited information. we only have the call stack from the crash report. We need to either mitigate the crash, or add additional asserts to get more information in future crash reports.

[sheetalkamat]

This exception is possible only if there was exception in the invocation of previous createProgram which resulted in us not creating new program and old program was partially used and still present as newProgram. Ideal thing to do here is to capture bugs where that exception happens and that could be done by logging the bug for the first exception in the session. I am going to close this bug as wont fix.