VS Code / TypeScript integration isn't configured correctly for notebook cells

[jaked]

• doesn't use project tsconfig.json
• has JSX configured wrong (so gives an error about React being a UMD global)
• can't find imported files (works OK for imported packages)

Advice from @Krzysztof-Cieslak about debugging:

Anyway... I guess if I'd want to debug this I'd start with following steps:
Set typescript.tsserver.enableTracing to true
Set typescript.tsserver.log to verbose
Reload the window
Go to TypeScript channel in the Output tab
There you should have path to the log file
Open file in your notebook and open normal TS file to generate some logs.
Compare the differences in the log file

[jaked]

here are some relevant-looking log messages when you create a new cell:

Info 2074 [12:32:59.988] Search path: ^/vscode-notebook-cell/ts-nul-authority/Users/jaked/repos/react-ts-example-2
Info 2075 [12:32:59.988] For info: ^/vscode-notebook-cell/ts-nul-authority/Users/jaked/repos/react-ts-example-2/test.vnb#W3sZmlsZQ== :: No config files found.
Info 2076 [12:32:59.988] Starting updateGraphWorker: Project: /dev/null/inferredProject1*
Err 2077  [12:32:59.989] languageId not found for ^/vscode-notebook-cell/ts-nul-authority/Users/jaked/repos/react-ts-example-2/test.vnb#W3sZmlsZQ==
Err 2078  [12:32:59.989] languageId not found for ^/vscode-notebook-cell/ts-nul-authority/Users/jaked/repos/react-ts-example-2/test.vnb#W3sZmlsZQ==
Info 2079 [12:32:59.997] Finishing updateGraphWorker: Project: /dev/null/inferredProject1* projectStateVersion: 54 projectProgramVersion: 9 structureChanged: true structureIsReused:: Not Elapsed: 9.251708000898361ms
Info 2080 [12:32:59.998] Project '/dev/null/inferredProject1*' (Inferred)

Judging from the way cells are assigned filenames, I think maybe imports of local files can't be found because the relative path isn't correct? Yup, if I give an absolute path it works.

Also maybe that's why config files aren't found? There's also these log messages:

Info 2122 [12:37:58.438] request:
    {
      "seq": 326,
      "type": "request",
      "command": "projectInfo",
      "arguments": {
        "file": "^/vscode-notebook-cell/ts-nul-authority/Users/jaked/repos/react-ts-example-2/test.vnb#W2sZmlsZQ==",
        "needFileNameList": false
      }
    }
Perf 2123 [12:37:58.441] 326::projectInfo: elapsed time (in milliseconds) 3.6483
Info 2124 [12:37:58.441] response:
    {"seq":0,"type":"response","command":"projectInfo","request_seq":326,"success":true,"body":{"configFileName":"/dev/null/inferredProject1*","languageServiceDisabled":false}}

which suggests that it's inferring a config file (because it can't find one relative to the path).

I wonder if there was some TypeScript support for these notebook pathnames that got broken somehow.

[jaked]

VS Code understands files starting with ^ to refer to in-memory resources, see

https://github.com/microsoft/vscode/blob/1.87.2/extensions/typescript-language-features/src/typescriptServiceClient.ts#L763

[jaked]

semanticDiag is an event sent from TypeScript to indicate a problem, e.g. when the imported file can't be found:

    {"seq":0,"type":"event","event":"semanticDiag","body":{"file":"^/vscode-notebook-cell/ts-nul-authority/Users/jaked/repos/react-ts-example-2/test.vnb#W2sZmlsZQ==","diagnostics":[{"start":{"line":1,"offset":21},"end":{"line":1,"offset":32},"text":"Cannot find module './test.ts' or its corresponding type declarations.","code":2307,"category":"error"}]}}

[jaked]

here's a relevant-looking log message from the TypeScript server (I think?!)

{"pid":1,"tid":1,"ph":"B","cat":"check","ts":243237142666.625,"name":"checkSourceFile","args":{"path":"/users/jaked/repos/react-ts-example-2/^/vscode-notebook-cell/ts-nul-authority/users/jaked/repos/react-ts-example-2/test.vnb#w3szmlszq=="}},

what's going on with the path there? guessing that's constructed client-side. I think actually it's getting the root path prepended server-side because it starts with ^.

[jaked]

seems like TypeScript in notebook cells isn't well-supported 😢

see microsoft/vscode#212367 disabling error highlighting in cells.

see DonJayamanne/typescript-notebook#79 (comment) microsoft/vscode#186811 microsoft/vscode#188186 about cell paths not working

[jaked]

see microsoft/vscode#183688 microsoft/vscode#183685 about finding tsconfig.json

[jaked]

ok looks like TypeScript understands ^ to mean that the file is "dynamic" (not present in the filesystem I think), see https://github.com/microsoft/TypeScript/blob/main/src/server/scriptInfo.ts#L348

(not sure why it is prepending the project root in that case)

[jaked]

I think dynamic files are supposed to look in the project root for their tsconfig.json, see microsoft/TypeScript#35111

[jaked]

the path in checkSourceFile above seems to be set here (prepending the root path since the filename starts with ^) https://github.com/microsoft/TypeScript/blob/main/src/services/services.ts#L1865

[jaked]

missing file error is defined here:

https://github.com/microsoft/TypeScript/blob/main/src/compiler/diagnosticMessages.json#L1887

(I think this gets compiled into a code file which is referenced from checker.ts)

called here (in checker.ts):

    function resolveExternalModuleName(location: Node, moduleReferenceExpression: Expression, ignoreErrors?: boolean): Symbol | undefined {
        const isClassic = getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.Classic;
        const errorMessage = isClassic ?
            Diagnostics.Cannot_find_module_0_Did_you_mean_to_set_the_moduleResolution_option_to_nodenext_or_to_add_aliases_to_the_paths_option
            : Diagnostics.Cannot_find_module_0_or_its_corresponding_type_declarations;
        return resolveExternalModuleNameWorker(location, moduleReferenceExpression, ignoreErrors ? undefined : errorMessage);
    }

[jaked]

looks like resolveExternalModuleName checks a previously-initialized map of import names, which is computed here https://github.com/microsoft/TypeScript/blob/27bcd4cb5a98bce46c9cdd749752703ead021a4b/src/compiler/program.ts#L4039

[jaked]

resolving import names boils down to https://github.com/microsoft/TypeScript/blob/27bcd4cb5a98bce46c9cdd749752703ead021a4b/src/compiler/program.ts#L2050 which doesn't consider dynamic paths afaict

[jaked]

I hacked around it by checking for the magic notebook cell pathname, and in that case passing through the underlying notebook pathname:

    function resolveModuleNamesWorker(moduleNames: readonly StringLiteralLike[], containingFile: SourceFile, reusedNames: readonly StringLiteralLike[] | undefined): readonly ResolvedModuleWithFailedLookupLocations[] {
        if (!moduleNames.length) return emptyArray;
        const cellPrefix = "^/vscode-notebook-cell/ts-nul-authority";
        const containingFileName =  
            containingFile.originalFileName.startsWith(cellPrefix) ?
            containingFile.originalFileName.substring(cellPrefix.length) :
            getNormalizedAbsolutePath(containingFile.originalFileName, currentDirectory);
        ...

and now

[jaked]

looks like TypeScript infers a project (called inferredProject{N}) and configuration when it can't find a tsconfig.json. the inferred project name is generated here https://github.com/microsoft/TypeScript/blob/27bcd4cb5a98bce46c9cdd749752703ead021a4b/src/server/utilitiesPublic.ts#L124

[jaked]

this ☝ is used in an InferredProject class https://github.com/microsoft/TypeScript/blob/27bcd4cb5a98bce46c9cdd749752703ead021a4b/src/server/project.ts#L2275 which is created via assignOrphanScriptInfoToInferredProject https://github.com/microsoft/TypeScript/blob/27bcd4cb5a98bce46c9cdd749752703ead021a4b/src/server/editorServices.ts#L1867