TypeError: Cannot read property 'lastIndexOf' of undefined in 'Object.startsWith' during 'completionEntryDetails'

[typescript-bot]

This issue comes from crash dumps in telemetry. We've tried to de-duplicate issues on a best-effort basis, comparing the sequence of methods called and the command requested while ignoring line numbers.
TypeScript version prefix: 3.8.3
VSCode version: 1.43.0
Command requested: completionEntryDetails
Hitting sessions: 3424
Five line hash: 3bf2792b241510a67cdb0d1ad5fb2ee5
Stack:

    at startsWith (tsserver.js:1894:20)
    at isPathRelativeToParent (tsserver.js:102582:23)
    at <anonymous> (tsserver.js:102541:24)
    at firstDefined (tsserver.js:197:26)
    at getPathRelativeToRootDirs (tsserver.js:102539:23)
    at tryGetModuleNameFromRootDirs (tsserver.js:102400:40)
    at getLocalModuleSpecifier (tsserver.js:102258:44)
    at <anonymous> (tsserver.js:102245:96)
    at getModuleSpecifiers (tsserver.js:102245:57)
    at <anonymous> (tsserver.js:127833:44)
    at flatMap (tsserver.js:465:25)
    at getNewImportInfos (tsserver.js:127831:52)
    at getImportCompletionAction (tsserver.js:127726:44)
    at getCompletionEntryCodeActionsAndSourceDisplay (tsserver.js:109912:33)
    at getCompletionEntryDetails (tsserver.js:109876:30)
    at getCompletionEntryDetails (tsserver.js:135365:35)
    at <anonymous> (tsserver.js:145465:57)
    at mapDefined (tsserver.js:562:30)
    at Session.getCompletionEntryDetails (tsserver.js:145463:33)
    at _a.<computed> (tsserver.js:144392:61)
    at <anonymous> (tsserver.js:146003:88)
    at Session.executeWithRequestId (tsserver.js:145994:28)
    at Session.executeCommand (tsserver.js:146003:33)
    at Session.onMessage (tsserver.js:146027:35)
    at <anonymous> (tsserver.js:147342:27)
    at unknown (suppressed.js)
    at unknown (suppressed.js)
    at unknown (suppressed.js)
    at unknown (suppressed.js)
    at unknown (suppressed.js)
    at unknown (suppressed.js)
    at unknown (suppressed.js)
    at unknown (suppressed.js)
    at unknown (suppressed.js)

[typescript-bot]

Revised stack format and updated hash.

[typescript-bot]

This issue reproduced in the following context:
TypeScript version prefix: 3.9.7
VSCode version: 1.48.0-insider
Command requested: encodedSemanticClassifications-full
Hitting sessions: 859
Five line hash: 3bf2792b241510a67cdb0d1ad5fb2ee5
Stack:

    at startsWith (tsserver.js:1910:20)
    at isPathRelativeToParent (tsserver.js:105036:23)
    at <anonymous> (tsserver.js:104995:24)
    at firstDefined (tsserver.js:197:26)
    at getPathRelativeToRootDirs (tsserver.js:104993:23)
    at tryGetModuleNameFromRootDirs (tsserver.js:104836:40)
    at getLocalModuleSpecifier (tsserver.js:104672:44)
    at <anonymous> (tsserver.js:104659:96)
    at getModuleSpecifiers (tsserver.js:104659:57)
    at getSpecifierForModuleSymbol (tsserver.js:39433:62)
    at createExpressionFromSymbolChain (tsserver.js:39610:49)
    at symbolToExpression (tsserver.js:39597:24)
    at <anonymous> (tsserver.js:38447:106)
    at withContext (tsserver.js:38485:37)
    at symbolToExpression (tsserver.js:38447:28)
    at symbolToStringWorker (tsserver.js:38373:30)
    at usingSingleLineStringWriter (tsserver.js:12956:13)
    at symbolToString (tsserver.js:38371:73)
    at getFullyQualifiedName (tsserver.js:37333:126)
    at getExternalModuleMember (tsserver.js:37034:42)
    at getTargetOfExportSpecifier (tsserver.js:37111:17)
    at getTargetOfAliasDeclaration (tsserver.js:37160:28)
    at resolveAlias (tsserver.js:37197:30)
    at resolveSymbol (tsserver.js:37187:67)
    at getSymbolIfSameReference (tsserver.js:37887:33)
    at <anonymous> (tsserver.js:37878:21)
    at forEachEntry (tsserver.js:12918:26)
    at getAliasForSymbolInContainer (tsserver.js:37877:23)
    at getAlternativeContainingModules (tsserver.js:37813:27)
    at getContainersOfSymbol (tsserver.js:37829:66)
    at getSymbolChain (tsserver.js:39289:41)
    at lookupSymbolChainWorker (tsserver.js:39275:51)
    at lookupSymbolChain (tsserver.js:39268:24)
    at symbolToName (tsserver.js:39573:29)
    at <anonymous> (tsserver.js:38444:106)
    at withContext (tsserver.js:38485:37)
    at symbolToEntityName (tsserver.js:38444:28)
    at createSignatureForJSXIntrinsic (tsserver.js:58947:56)
    at resolveJsxOpeningLikeElement (tsserver.js:58959:37)
    at resolveSignature (tsserver.js:59003:28)
    at getResolvedSignature (tsserver.js:59025:26)
    at getContextualTypeForArgumentAtIndex (tsserver.js:55207:118)
    at getContextualJsxElementAttributesType (tsserver.js:55620:20)
    at getContextualType (tsserver.js:55605:28)
    at getApparentTypeOfContextualType (tsserver.js:55474:17)
    at getContextualTypeForJsxAttribute (tsserver.js:55430:38)
    at getContextualType (tsserver.js:55602:28)
    at getContextualTypeForJsxExpression (tsserver.js:55420:19)
    at getContextualType (tsserver.js:55599:28)
    at getApparentTypeOfContextualType (tsserver.js:55474:17)
    at getContextualTypeForObjectLiteralElement (tsserver.js:55368:24)
    at getContextualType (tsserver.js:55580:28)
    at checkExpressionForMutableLocation (tsserver.js:61209:121)
    at checkPropertyAssignment (tsserver.js:61218:20)
    at getTypeOfVariableOrParameterOrPropertyWorker (tsserver.js:41962:72)
    at getTypeOfVariableOrParameterOrProperty (tsserver.js:41888:28)
    at getTypeOfSymbol (tsserver.js:42216:24)
    at getTypeOfNode (tsserver.js:67181:28)
    at getTypeAtLocation (tsserver.js:35049:31)
    at unknown (suppressed.js:149:38)
    at unknown (suppressed.js:86:35)
    at visitNode (tsserver.js:18797:24)
    at forEachChild (tsserver.js:18882:21)
    at unknown (suppressed.js:116:16)
    at visitNodes (tsserver.js:18806:30)
    at forEachChild (tsserver.js:18976:24)
    at unknown (suppressed.js:116:16)
    at visitNode (tsserver.js:18797:24)
    at forEachChild (tsserver.js:19213:21)
    at unknown (suppressed.js:116:16)
    at visitNode (tsserver.js:18797:24)
    at forEachChild (tsserver.js:19208:21)
    at unknown (suppressed.js:116:16)
    at visitNodes (tsserver.js:18806:30)
    at forEachChild (tsserver.js:19205:24)
    at unknown (suppressed.js:116:16)
    at visitNode (tsserver.js:18797:24)
    at forEachChild (tsserver.js:19203:21)
    at unknown (suppressed.js:116:16)
    at visitNode (tsserver.js:18797:24)
    at forEachChild (tsserver.js:19192:24)
    at unknown (suppressed.js:116:16)
    at visitNodes (tsserver.js:18806:30)
    at forEachChild (tsserver.js:19193:21)
    at unknown (suppressed.js:116:16)
    at visitNodes (tsserver.js:18806:30)
    at forEachChild (tsserver.js:19193:21)
    at unknown (suppressed.js:116:16)
    at visitNodes (tsserver.js:18806:30)
    at forEachChild (tsserver.js:19193:21)
    at unknown (suppressed.js:116:16)
    at visitNode (tsserver.js:18797:24)
    at forEachChild (tsserver.js:19000:24)
    at unknown (suppressed.js:116:16)
    at visitNode (tsserver.js:18797:24)
    at forEachChild (tsserver.js:19077:24)
    at unknown (suppressed.js:116:16)
    at visitNodes (tsserver.js:18806:30)
    at forEachChild (tsserver.js:19037:24)

[typescript-bot]

This issue reproduced in the following context:
TypeScript version prefix: 4.5.5
VSCode version: 1.64.2
Command requested: completionInfo
Hitting sessions: 1507
Five line hash: 3bf2792b241510a67cdb0d1ad5fb2ee5
Stack:

    at startsWith (tsserver.js:2077:20)
    at isPathRelativeToParent (tsserver.js:119556:23)
    at <anonymous> (tsserver.js:119502:24)
    at firstDefined (tsserver.js:227:26)
    at getPathRelativeToRootDirs (tsserver.js:119500:23)
    at tryGetModuleNameFromRootDirs (tsserver.js:119318:40)
    at getLocalModuleSpecifier (tsserver.js:118976:44)
    at computeModuleSpecifiers (tsserver.js:118944:33)
    at getModuleSpecifiersWithCacheInfo (tsserver.js:118904:26)
    at unknown (tsserver.js:148670:81)
    at <anonymous> (tsserver.js:148674:26)
    at flatMap (tsserver.js:522:25)
    at getNewImportFixes (tsserver.js:148672:28)
    at getModuleSpecifierForBestExportInfo (tsserver.js:148489:22)
    at tryResolve (tsserver.js:128278:34)
    at <anonymous> (tsserver.js:129980:46)
    at <anonymous> (tsserver.js:125931:21)
    at forEach (tsserver.js:125929:28)
    at <anonymous> (tsserver.js:129962:32)
    at resolvingModuleSpecifiers (tsserver.js:128261:26)
    at collectAutoImports (tsserver.js:129961:17)
    at getGlobalCompletions (tsserver.js:129866:17)
    at tryGetGlobalSymbols (tsserver.js:129772:25)
    at getCompletionData (tsserver.js:129507:17)
    at getCompletionsAtPosition (tsserver.js:128325:34)
    at getCompletionsAtPosition (tsserver.js:160077:35)
    at Session.getCompletions (tsserver.js:171546:64)
    at _a.<computed> (tsserver.js:170391:61)
    at <anonymous> (tsserver.js:172195:88)
    at Session.executeWithRequestId (tsserver.js:172186:28)
    at Session.executeCommand (tsserver.js:172195:33)
    at Session.onMessage (tsserver.js:172221:35)
    at <anonymous> (tsserver.js:174826:31)
    at unknown (suppressed.js:315:20)
    at unknown (suppressed.js:337:10)
    at unknown (suppressed.js:482:12)
    at unknown (suppressed.js:194:10)
    at unknown (suppressed.js:315:20)
    at unknown (suppressed.js:309:12)
    at unknown (suppressed.js:284:9)
    at unknown (suppressed.js:223:10)
    at unknown (suppressed.js:188:23)