VS tsserver crash in openExternalProjects: Error processing request. Debug Failure. False expression.

[minestarks]

New in 3.7

This LS crash is the current top hitter in Visual Studio. I have not found a corresponding auto-filed bug, which implies it's not impacting VS Code.

Seen in Visual Studio versions: ["16.5.29521.150","16.5.29504.125","16.4.29519.181","16.4.29519.161","16.4.29411.138","16.3.29503.13","16.3.29519.87","16.3.29411.108","16.3.29326.143","16.3.29509.3"]

TypeScript version: ["3.7.2","3.7.1-rc","3.7.0-beta","3.7.3"]
Command: openExternalProjects

Message: Error processing request. Debug Failure. False expression.
Stack trace:

declareSymbol(tsserver.js:29174:22)
declareSourceFileMember(tsserver.js:30473:19)
declareSymbolAndAddToSymbolTable(tsserver.js:30420:28)
bindThisPropertyAssignment(tsserver.js:31334:25)
bindWorker(tsserver.js:30985:29)
bind(tsserver.js:30867:13)
visitNode(tsserver.js:17584:24)
Object.forEachChild(tsserver.js:17998:21)
bindEachChild(tsserver.js:29481:16)
bindChildrenWorker(tsserver.js:29576:21)
bindChildren(tsserver.js:29451:17)
bind(tsserver.js:30878:21)
bindEach(tsserver.js:29473:21)
visitNodes(tsserver.js:17589:24)
Object.forEachChild(tsserver.js:17978:21)
bindEachChild(tsserver.js:29481:16)
bindChildrenWorker(tsserver.js:29576:21)
bindChildren(tsserver.js:29451:17)
bind(tsserver.js:30878:21)
bindEach(tsserver.js:29473:21)
visitNodes(tsserver.js:17589:24)
Object.forEachChild(tsserver.js:17978:21)
bindEachChild(tsserver.js:29481:16)
bindChildrenWorker(tsserver.js:29576:21)
bindChildren(tsserver.js:29451:17)
bind(tsserver.js:30878:21)
bindEach(tsserver.js:29473:21)
visitNodes(tsserver.js:17589:24)
Object.forEachChild(tsserver.js:17978:21)
bindEachChild(tsserver.js:29481:16)
bindChildrenWorker(tsserver.js:29576:21)
bindChildren(tsserver.js:29451:17)
bind(tsserver.js:30878:21)
bindEach(tsserver.js:29473:21)
visitNodes(tsserver.js:17589:24)
Object.forEachChild(tsserver.js:17978:21)
bindEachChild(tsserver.js:29481:16)
bindChildrenWorker(tsserver.js:29576:21)
bindChildren(tsserver.js:29451:17)
bind(tsserver.js:30878:21)
bindExpressionStatement(tsserver.js:30068:13)
bindChildrenWorker(tsserver.js:29530:21)
bindChildren(tsserver.js:29451:17)
bind(tsserver.js:30878:21)
bindLabeledStatement(tsserver.js:30084:13)
bindChildrenWorker(tsserver.js:29533:21)
bindChildren(tsserver.js:29451:17)
bind(tsserver.js:30878:21)
unknown_function(tsserver.js:29457:94)
bindEach(tsserver.js:29473:21)
bindEachFunctionsFirst(tsserver.js:29457:13)
bindChildrenWorker(tsserver.js:29567:21)
bindChildren(tsserver.js:29451:17)
bindContainer(tsserver.js:29397:17)
bind(tsserver.js:30881:21)
bindSourceFile(tsserver.js:29030:17)
Object.bindSourceFile(tsserver.js:28967:9)
initializeTypeChecker(tsserver.js:64332:20)
Object.createTypeChecker(tsserver.js:33586:9)
Object.getTypeChecker(tsserver.js:95558:79)
synchronizeHostData(tsserver.js:130590:21)
Object.getProgram(tsserver.js:130672:13)
ExternalProject.Project.updateGraphWorker(tsserver.js:135023:53)
ExternalProject.Project.updateGraph(tsserver.js:134966:42)
ExternalProject.updateGraph(tsserver.js:135963:59)
ProjectService.openExternalProject(tsserver.js:138655:29)
ProjectService.openExternalProjects(tsserver.js:138406:26)
Session.handlers.ts.createMapFromTemplate._a.(tsserver.js:139167:46)
unknown_function(tsserver.js:140854:88)
IOSession.Session.executeWithRequestId(tsserver.js:140845:28)
IOSession.Session.executeCommand(tsserver.js:140854:33)
IOSession.Session.onMessage(tsserver.js:140877:35)
Interface.(tsserver.js:142192:27)
suppressed_frame()
suppressed_frame()
suppressed_frame()
suppressed_frame()
suppressed_frame()
suppressed_frame()
suppressed_frame()
suppressed_frame()
suppressed_frame()

ADO link: https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1034740

[minestarks]

Sample user report:
https://developercommunity.visualstudio.com/content/problem/852813/javascript-intellisense-not-working-after-update-1.html

[RyanCavanaugh]

Made a repro from the call stack

this["a" + "b"] = 0;

[minestarks]

@RyanCavanaugh @sandersn this may be a dupe, but I'm not sure since the callstack is slightly different. Could you confirm? https://developercommunity.visualstudio.com/content/problem/851128/using-typescript-37-for-intellisense.html

[sandersn]

New and exciting call stack for the code:

this["a" + "b"] = 0
module.exports.foo = function () { return 1 }

The cause (and fix) is almost certainly the same, the module code path just gets further than the global path before crashing.

TypeError: Cannot read property 'flags' of undefined
    at Object.getCheckFlags (/home/nathansa/ts/built/local/tsserver.js:16294:23)
    at getTypeOfSymbol (/home/nathansa/ts/built/local/tsserver.js:39757:20)
    at checkFunctionExpressionOrObjectLiteralMethod (/home/nathansa/ts/built/local/tsserver.js:56882:24)
    at checkExpressionWorker (/home/nathansa/ts/built/local/tsserver.js:58359:28)
    at checkExpression (/home/nathansa/ts/built/local/tsserver.js:58260:38)
    at checkBinaryLikeExpression (/home/nathansa/ts/built/local/tsserver.js:57521:29)
    at checkBinaryExpression (/home/nathansa/ts/built/local/tsserver.js:57496:20)
    at checkExpressionWorker (/home/nathansa/ts/built/local/tsserver.js:58380:28)
    at checkExpression (/home/nathansa/ts/built/local/tsserver.js:58260:38)
    at checkExpressionStatement (/home/nathansa/ts/built/local/tsserver.js:60635:13)
    at checkSourceElementWorker (/home/nathansa/ts/built/local/tsserver.js:63045:28)
    at checkSourceElement (/home/nathansa/ts/built/local/tsserver.js:62928:17)
    at Object.forEach (/home/nathansa/ts/built/local/tsserver.js:151:30)
    at checkSourceFileWorker (/home/nathansa/ts/built/local/tsserver.js:63249:20)
    at checkSourceFile (/home/nathansa/ts/built/local/tsserver.js:63218:13)
    at getDiagnosticsWorker (/home/nathansa/ts/built/local/tsserver.js:63296:17)
    at Object.getDiagnostics (/home/nathansa/ts/built/local/tsserver.js:63282:24)
    at /home/nathansa/ts/built/local/tsserver.js:95944:85
    at runWithCancellationToken (/home/nathansa/ts/built/local/tsserver.js:95909:24)
    at getSemanticDiagnosticsForFileNoCache (/home/nathansa/ts/built/local/tsserver.js:95932:20)
    at getAndCacheDiagnostics (/home/nathansa/ts/built/local/tsserver.js:96185:26)
    at getSemanticDiagnosticsForFile (/home/nathansa/ts/built/local/tsserver.js:95929:20)
    at getDiagnosticsHelper (/home/nathansa/ts/built/local/tsserver.js:95871:24)
    at Object.getSemanticDiagnostics (/home/nathansa/ts/built/local/tsserver.js:95884:20)
    at Object.getSemanticDiagnostics (/home/nathansa/ts/built/local/tsserver.js:131020:47)
    at /home/nathansa/ts/built/local/tsserver.js:140369:140
    at IOSession.Session.getDiagnosticsWorker (/home/nathansa/ts/built/local/tsserver.js:140239:35)
    at IOSession.Session.getSemanticDiagnosticsSync (/home/nathansa/ts/built/local/tsserver.js:140369:29)
    at Session.handlers.ts.createMapFromTemplate._a.(anonymous function) (/home/nathansa/ts/built/local/tsserver.js:139744:61)
    at /home/nathansa/ts/built/local/tsserver.js:141239:88
    at IOSession.Session.executeWithRequestId (/home/nathansa/ts/built/local/tsserver.js:141230:28)
    at IOSession.Session.executeCommand (/home/nathansa/ts/built/local/tsserver.js:141239:33)
    at IOSession.Session.onMessage (/home/nathansa/ts/built/local/tsserver.js:141262:35)
    at Interface.<anonymous> (/home/nathansa/ts/built/local/tsserver.js:142577:27)
    at emitOne (events.js:116:13)
    at Interface.emit (events.js:211:7)
    at Interface._onLine (readline.js:282:10)
    at Interface._normalWrite (readline.js:424:12)
    at Socket.ondata (readline.js:141:10)
    at emitOne (events.js:116:13)
    at Socket.emit (events.js:211:7)
    at addChunk (_stream_readable.js:263:12)
    at readableAddChunk (_stream_readable.js:250:11)
    at Socket.Readable.push (_stream_readable.js:208:10)
    at Pipe.onread (net.js:607:20)

[sandersn]

@minestarks the important parts -- bindThisPropertyAssignment and declareSymbolAndAddToSymbolTable -- are the same. It's a dupe.

[sandersn]

We forget to handle dynamic names in the source file binding case. There's nothing sensible we can do, so dynamic names should in a top-level this-property assignment should be skipped.

[sandersn]

Fix is ready.

[sandersn]

This is now in 3.7 as well.