Intellisense is slow and some things don't work

[mhamann]

Intellisense is slow and some things don't work

[RyanCavanaugh]

@mhamann you should be able to attach a debugger using the instructions here https://github.com/Microsoft/TypeScript/wiki/Debugging-Language-Service-in-VS-Code

I'd add a conditional break here:

        if (current.escapedName !== InternalSymbolName.Default && current.escapedName !== InternalSymbolName.ExportEquals) {
            const final = cb(current.name);
            if (final) return final;
        }
        if (chain.length > 10000) debugger; // <--- ADD
        chain = append(chain, current);
        current = current.flags & SymbolFlags.Alias ? checker.getImmediateAliasedSymbol(current) : undefined;

and see what's going on. The info in the locals in that function should give you a pretty good idea of what's going on. It looks like there's a thing we wrongly believe to be an alias of itself, but that construction should be impossible. It should be possible to make a minimal repro using only the relevant declarations from your code

[mjbvz]

Are you able to share a project which demonstrates this issue?

[RyanCavanaugh]

Invalid array length
RangeError: Invalid array length
at Array.push ()
at append

This stack would indicate an array hitting the 4 billion element cap... 😨

[mhamann]

@mjbvz unfortunately, I can't share the project directly. it's proprietary code. happy to hop on a screen share or run specific commands if that would help.

@RyanCavanaugh i'm wondering if there's a looping issue somewhere here, because there's no way this project is that big.

[szuend]

We see this error in the Chrome DevTools code base. We use the bundled tsserver in node_modules/typescript/lib which is 5.5.3.

Instructions for getting the source: https://chromium.googlesource.com/devtools/devtools-frontend/+/main/docs/get_the_code.md#standalone-checkout-checking-out-source

No building required, just open the checkout with any IDE that uses either the bundled tsserver or some 5.5 version for LSP.

[szuend]

Unfortunately I don't have concrete repro steps to trigger the RangeError. It happened a couple of times while working in NamesResolver.ts (specifically while working on this CL https://crrev.com/c/5718090).

The relevant part of the log:

Err 10497 [10:19:48.042] Exception on executing command {
  "seq": 1388,
  "type": "request",
  "command": "getCodeFixes",
  "arguments": {
    "file": "<path>/devtools/devtools-frontend/front_end/models/source_map_scopes/NamesResolver.ts",
    "startLine": 642,
    "startOffset": 17,
    "endLine": 642,
    "endOffset": 27,
    "errorCodes": [
      2304
    ],
    "startPosition": 24760,
    "endPosition": 24770
  }
}:

    Invalid array length

    RangeError: Invalid array length
        at Array.push (<anonymous>)
        at append (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:2976:6)
        at forEachNameOfDefaultExport (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:138688:13)
        at <path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:155182:115
        at <path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:138534:119
        at forEachExternalModule (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:138594:7)
        at forEachExternalModuleToImportFrom (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:138534:3)
        at getExportInfos (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:155177:3)
        at <path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:155113:24
        at flatMap (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:2629:17)
        at getFixesInfoForNonUMDImport (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:155107:10)
        at getFixInfos (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:154943:12)
        at Object.getCodeActions (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:154086:18)
        at <path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:151145:46
        at flatMap (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:2629:17)
        at Object.getFixes (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:151145:10)
        at <path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:149425:33
        at flatMap (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:2629:17)
        at Object.getCodeFixesAtPosition (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:149423:12)
        at IpcIOSession.getCodeFixes (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:191090:50)
        at getCodeFixes (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:189174:43)
        at <path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:191397:69
        at IpcIOSession.executeWithRequestId (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:191389:14)
        at IpcIOSession.executeCommand (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:191397:29)
        at IpcIOSession.onMessage (<path>/devtools/devtools-frontend/node_modules/typescript/lib/typescript.js:191439:51)
        at process.<anonymous> (<path>/devtools/devtools-frontend/node_modules/typescript/lib/tsserver.js:523:14)
        at process.emit (node:events:514:28)
        at emit (node:internal/child_process:937:14)
        at process.processTicksAndRejections (node:internal/process/task_queues:83:21)

[mhamann]

This looks like it could be the same bug: #59201

The latest VS Code - Insiders build seems to be working for me...