lsp hangs when a javascript and typescript file have the same name

[joshcartme]

repro: https://github.com/joshcartme/tsgo-duplicate-file-bug

If you have a js and ts file with the same name, rootNames in the computed config ends up with a "" entry. This seems to hang the server, it never starts responding. For example in the repro posted above I have lib.ts and lib.js, lib.js appears to get resolved as "" in rootNames.

This may be the same as #670

Output from the VSCode extension:

Resolved to /home/repro/.vscode-server/extensions/typescriptteam.native-preview-0.20250529.1-linux-x64/lib/tsgo
Starting language server...
Info 0    [14:36:15.239] currentDirectory:: /home/repro/development/tsgo-duplicate-file-bug useCaseSensitiveFileNames:: true
Info 1    [14:36:15.240] libs Location:: /home/repro/.vscode-server/extensions/typescriptteam.native-preview-0.20250529.1-linux-x64/lib
Info 2    [14:36:15.244] getConfigFileNameForFile:: File: /home/repro/development/tsgo-duplicate-file-bug/index.ts ProjectRootPath: :: Result: /home/repro/development/tsgo-duplicate-file-bug/tsconfig.json
Info 3    [14:36:15.244] Creating KindConfiguredProject: /home/repro/development/tsgo-duplicate-file-bug/tsconfig.json, currentDirectory: /home/repro/development/tsgo-duplicate-file-bug
Info 4    [14:36:15.244] Config: /home/repro/development/tsgo-duplicate-file-bug/tsconfig.json : {
      "options": {
        "allowJs": true,
        "configFilePath": "/home/repro/development/tsgo-duplicate-file-bug/tsconfig.json"
      },
      "projectReferences": [],
      "rootNames": [
        "/home/repro/development/tsgo-duplicate-file-bug/index.ts",
        "",
        "/home/repro/development/tsgo-duplicate-file-bug/lib.ts"
      ]
    }

It's very easy to end up with a js and ts file with the same name if you don't have an outDir in your tsconfig

[joshcartme]

I'm very much a go novice, but I've been attempting to debug this. When execution gets to

typescript-go/internal/tsoptions/tsconfigparsing.go

Line 1490 in dd11489

wildcardFiles.Delete(lowerPriorityPath)

it correctly deletes the js file from wildcardFiles, the keys in the OrderedMap has zero length, but in the outer scope here

typescript-go/internal/tsoptions/tsconfigparsing.go

Line 1578 in dd11489

removeWildcardFilesWithLowerPriorityExtension(file, wildcardFileMap, supportedExtensions, keyMappper)

wildcardFileMap has a "" in keys.

inner scope with keys of length 0:

outer scope with keys of length 1:

If I attempt to edit the "" key in the outer scope it says "Unable to lookup variable: could not find symbol value for wildcardFileMap",

[jakebailey]

Thanks, you've found the bug, which is that we are passing the map by value when it should be by reference (pointer). The inner delete works and succeeds on the map (which is a pointer), but then the slice does not work (it's not a pointer, but a value type).

[joshcartme]

Ok yeah, thanks for the explanation! I was starting to wonder if it had something to do with passing by reference vs value but wasn't sure that was even a thing in go.

[jakebailey]

See #1003 for the fix; the important bit is just the * 😄 (the rest is to prevent the bug from happening again)

[joshcartme]

Wonderful, thank you!