Bug Report

The basic problem looks like this:

1. I run tsc directly from the command line and get Set A of errors.
2. VSCode instead shows Set B of errors which can be wildly different than Set A
3. If I issue the TypeScript: Restart TS Server command to VSCode, I will then start to just see Set A errors in my IDE
4. However... if I go and make a small change to a file I start only seeing Set B errors again.

Set B errors seem completely wrong since the tsc doesn't produce them. HOWEVER, a specfically unique error in Set B seems to be causing this weird behavior:

'Value' implicitly has type 'any' because it does not have a type annotation and is referenced directly
or indirectly in its own initializer.ts(7022)

If I solve this error with an explicit type assertion, the inconsistency goes away and I resume seeing Set A errors.

My project does rely on a deep set of types involving conditionals and generics. This seems to have something to do with causing this problem. I've provided a repository below with steps on how to reproduce. I would try to narrow the behavior down to a simpler project+repo but do not have the time at the moment.

Original Discord discussion

🔎 Search Terms

inconsistency, inconsistent, errors, ts language server,

🕗 Version & Regression Information

This issue was tested and occurs in TypeScript 4.9 and the latest nightly build as of this writing (5.0.0-dev.20230216).

⏯ Playground Link

Unfortunately I'm unable to reproduce this with the TS Playground

Repo+Branch that reproduces the issue

• Navigate to Stepper.ts line 77. See the TSDoc comment there for reproducibility steps. It can some times take a few file modifications to trigger the behavior.
• I was able to reproduce the same issue using GitHub Codespaces.

💻 Code

See Repo above.

🙁 Actual behavior

• TypeScript errors reported by VSCode are inconsistent with the ones reported by running tsc via the command line.
• VSCode can be temporarily made consistent by restarting the TS Server.
• A single error seems to be causing TS+VSCode to act in this way.

🙂 Expected behavior

• TypeScript errors reported by VSCode should always match with the ones reported by running tsc via the command line.