TSServer getCodeFixes results in `Debug Failure. False expression: Token end is child end`

[sirikon]

Bug Report

Encountered a problem while working with TypeScript on VSCode. The problem is pretty obscure, but it can be reproduced by following these instructions

1. Clone this repository: https://github.com/sirikon-experiments/tsserver-bug
2. Inside the repository, with NodeJS 18.12.1, run npm install
3. Open VSCode on the repository
4. Open src/helper.ts and keep it in a tab, don't close it.
5. Open src/main.ts, place the cursor over logContents on line 5 and hit Ctrl + . (Or whatever key combination you use for opening quick fixes).
   5.1. It displays No code actions available.
6. Open src/models.ts and comment half of the defined keys in the file, lines 15 to 29 for example.
7. Go back to src/main.ts and try again opening the quick fixes over logContents as before.
   7.1. It displays the quick fixes properly, recommending Add import from "./helper"
8. Uncommenting lines 15 to 29 in src/models.ts makes the quick fixes disappear again. Another way to make it work in src/main.ts is to change logContents(data); to logContents(); and ask for quick fixes again.
9. In VSCode: Ctrl + Shift + P -> TypeScript: Open TS Server Log -> You'll see errors like these:

    Debug Failure. False expression: Token end is child end

    Error: Debug Failure. False expression: Token end is child end
        at processChildNode (/home/sirikon/repos/tsserver-bug/node_modules/typescript/lib/tsserver.js:150867:38)
        at /home/sirikon/repos/tsserver-bug/node_modules/typescript/lib/tsserver.js:150803:21
        at visitNode (/home/sirikon/repos/tsserver-bug/node_modules/typescript/lib/tsserver.js:31215:24)
        at forEachChildInPropertySignature (/home/sirikon/repos/tsserver-bug/node_modules/typescript/lib/tsserver.js:31310:17)
        at Object.forEachChild (/home/sirikon/repos/tsserver-bug/node_modules/typescript/lib/tsserver.js:31998:47)
        at processNode (/home/sirikon/repos/tsserver-bug/node_modules/typescript/lib/tsserver.js:150802:20)
        at processChildNode (/home/sirikon/repos/tsserver-bug/node_modules/typescript/lib/tsserver.js:150874:21)
        at processChildNodes (/home/sirikon/repos/tsserver-bug/node_modules/typescript/lib/tsserver.js:150929:48)

🔎 Search Terms

• "Debug Failure. False expression: Token end is child end"

🕗 Version & Regression Information

Happens, at least, on versions 4.9.4 and 4.9.3, didn't try more versions for now.

🙁 Actual behavior

Given the instructions, the presented scenario results in errors when tsserver is asked for code fixes, but it should work as expected, as everything else.

🙂 Expected behavior

Given the instructions, quick fixes should work always regardless of the amount of keys in a model.

[iisaduan]

This was fixed with #54432