ErrLookup › microsoft/TypeScript
microsoft/TypeScript
TypeScript is a superset of JavaScript that compiles to clean JavaScript output. · TypeScript · 737 source files
Analyzed at b465fdbfe1 on 2026-08-12. 82 documented errors.
| Code / Message | Type | Severity | Tags |
|---|---|---|---|
| LanguageService Operation | exception | error | language-service, semantic-mode, diagnostics, typescript |
| LanguageService Operation | exception | error | language-service, semantic-mode, intellisense, typescript |
| getDefaultLibFilePath is only supported when consumed as a… | exception | error | compiler-host, sys, browser, node, lib-d-ts |
| Invalid name for template cancellation pipe: it should have… | exception | error | tsserver, named-pipe, cancellation, command-line, windows |
| You need to change the source code of fourslash test to use… | exception | error | fourslash, migration, semantic-classification, test-authoring |
| ( , ) | exception | error | fourslash, test-parsing, marker-syntax, range-syntax |
| is a string value; tsconfig JSON must be parsed with… | exception | error | compiler-api, createprogram, configuration, tsconfig, options |
| Only declaration files should be generated when… | exception | error | harness, compiler-output, declaration, emit, emit-declaration-only |
| Cannot read private member from an object whose class did… | exception | error | private-fields, runtime, downlevel, brand-check, emit-helpers |
| Private accessor was defined without a getter | exception | error | private-fields, runtime, downlevel, accessor, emit-helpers |
| No Project. | exception | error | server, tsserver, project, lifecycle |
| Invalid arguments | exception | error | overloads, deprecation, compat, type-narrowing |
| The project's language service is disabled. | exception | error | server, tsserver, project, resource-limits, language-service |
| Expected at least one js file to be emitted or at least one… | exception | error | test-harness, baseline, emit, compiler-options |
| Request: not allowed in LanguageServiceMode.Syntactic | exception | error | server, tsserver, server-mode, protocol |
| Syntax error in | exception | error | fourslash, test-syntax, transpile-error |
| DeprecationError: ' ' has been deprecated since v and can… | exception | error | deprecation, compat, versioning, migration |
| Request: not allowed in LanguageServiceMode.PartialSemantic | exception | error | server, tsserver, server-mode, protocol |
| Did you mean to put 'preferences' in the previous… | exception | error | fourslash, completions, api-misuse, preferences |
| verifyTextAtCaretIs\n | exception | error | fourslash, test-assertion, caret-position |
| Cannot replace the LKG unless all built targets are present… | exception | error | build, lkg, validation, localization |
| Symbol.asyncDispose is not defined. | exception | error | disposable, async-disposable, using, runtime, polyfill, emit-helpers |
| There were no errors and declFiles generated did not match… | exception | error | harness, compiler-output, declaration, emit, file-count-mismatch |
| Could not resolve JS module | exception | error | module-resolution, compiler-api, node-modules, configuration |
| tsserverlibrary requires CommonJS; use typescript.js instead | exception | error | build, commonjs, esm, browser, tsserverlibrary |
| Function expected | exception | error | decorators, runtime, emit-helpers, es-decorators |
| Non-comment test content appears before the first '//… | exception | error | test-harness, test-parser, multifile-test, authoring |
| Global option ' ' already exists | exception | error | fourslash, test-parsing, configuration, duplicate-option |
| Number of sourcemap files should be same as js files. | exception | error | harness, compiler-output, sourcemap, file-count-mismatch |
| The baseline for in files has changed | exception | error | test-harness, baseline, multifile, aggregated |
| getPreProcessedFileInfo is not available using the server… | exception | error | test-harness, language-service, server-adapter, unsupported-api |
| start < 0 | exception | error | textspan, compiler-api, internal-invariant, position |
| Unknown value ' ' for compiler option ' '. | exception | error | harness, compiler-options, configuration, invalid-value |
| Cannot shadow a mutable file system. | exception | error | test-harness, vfs, readonly, filesystem |
| Cannot use 'in' operator on non-object | exception | error | private-fields, runtime, downlevel, in-operator, emit-helpers |
| Could not find file: ' '. | exception | error | language-service, host, script-snapshot, embedding |
| \n ' ' was not updated while configuring for a prerelease… | exception | error | release, publish, idempotency, prerelease |
| Object expected. | exception | error | disposable, using, runtime, downlevel, emit-helpers |
| Exactly one refactor range is allowed per test. | exception | error | fourslash, refactor, test-configuration, range-markers |
| Symbol.dispose is not defined. | exception | error | disposable, using, runtime, polyfill, emit-helpers |
| Unknown compiler option | exception | error | harness, compiler-options, configuration, unknown-option |
| getClassifier is not available using the server interface. | exception | error | test-harness, language-service, server-adapter, unsupported-api |
| Cannot call andApplyCodeAction on multiple completions… | exception | error | fourslash, completions, api-misuse, code-action |
| verifyCurrentLineContent\n | exception | error | test-harness, fourslash, assertion, formatting |
| Cannot create a case-insensitive file system from a… | exception | error | test-harness, vfs, case-sensitivity, filesystem |
| New baseline created at | exception | error | test-harness, baseline, first-time, accept |
| Three-slash line in the middle of four-slash region at line | exception | error | fourslash, test-parsing, comment-syntax |
| verifyFileContent in file | exception | error | test-harness, fourslash, assertion, baseline |
| Cannot write private member to an object whose class did… | exception | error | private-fields, runtime, downlevel, brand-check, emit-helpers |
| Generator is already executing. | exception | error | generators, runtime, emit-helpers |
| Private method is not writable | exception | error | private-fields, runtime, downlevel, method, emit-helpers |
| The baseline file has changed. (Run "hereby… | exception | error | test-harness, baseline, diff, regression |
| LKG cannot be created when --bundle=false | exception | error | build, lkg, bundle, hereby |
| newLength < 0 | exception | error | textspan, textchangerange, compiler-api, internal-invariant, incremental |
| Object not disposable. | exception | error | disposable, using, runtime, emit-helpers |
| Cannot add initializers after decoration has completed | exception | error | decorators, runtime, emit-helpers, initializers |
| Project ' ' does not contain document | exception | error | server, tsserver, project, script-info, routing |
| Provided test options exceeded the maximum number of… | exception | error | test-harness, test-options, varyby, combinatorial |
| Cannot have undefined value for compiler option | exception | error | harness, compiler-options, configuration, undefined-value |
| No sourcemap files should be generated if inlineSourceMaps… | exception | error | harness, compiler-output, sourcemap, inline-sourcemap, declaration-map |
| Unknown marker " " Available markers | exception | error | fourslash, markers, name-mismatch |
| Variations in test option '@ | exception | error | test-harness, test-options, varyby, configuration |
| tracing requires having fs\n | exception | error | tracing, runtime, fs, bundler, compiler-api |
| The generated content was "undefined". Return "null" if no… | exception | error | test-harness, baseline, null-undefined, api-contract |
| Unexpected tag name ' '. | exception | error | release, publish, validation, prerelease |
| Diagnostic code appears more than once. | exception | error | diagnostics, build, validation, codegen |
| Symbol.iterator is not defined. | exception | error | iteration, runtime, polyfill, target, emit-helpers |
| No script with name '" + fileName + "' | exception | error | test-harness, language-service, script-info, setup |
| File index ( ) in openFile was out of range. There are only… | exception | error | fourslash, file-management, index-out-of-range |
| Object is not iterable. | exception | error | iteration, runtime, emit-helpers |
| patch does not match. | exception | error | release, version, validation, prerelease |
| No test file named " " exists. Available file names are | exception | error | fourslash, file-management, name-mismatch |
| Value must be a number, got | exception | error | harness, compiler-options, configuration, type-mismatch |
| Private accessor was defined without a setter | exception | error | private-fields, runtime, downlevel, accessor, emit-helpers |
| Expected to be a directory | exception | error | lkg, localization, build, validation |
| Failed to update status comment | exception | error | ci, github-api, network, release, retry |
| Symbol.asyncIterator is not defined. | exception | error | async, runtime, polyfill, target, emit-helpers |
| length < 0 | exception | error | textspan, compiler-api, internal-invariant, position |
| Expected to be a file | exception | error | lkg, localization, build, validation |
| failed | exception | error | build, subprocess, orchestration, release |
| Object expected | exception | error | decorators, accessor, runtime, emit-helpers |
| Class extends value is not a constructor or null | exception | error | classes, inheritance, runtime, emit-helpers |