TS cache corruption leads to "error TS2590: Expression produces a union type that is too complex to represent"

[jayshah123]

🔎 Search Terms

"typescript cache corruption", "typescript Expression produces a union type that is too complex to represent", "tsconfig.tsbuildinfo"

🕗 Version & Regression Information

• This is a error during typechecking.
• This is the behavior in every version I tried, and I reviewed the FAQ for entries about caching.
• I was unable to test this on prior versions because hard to migrate large codebase
• Using typescript@4.9.5

⏯ Playground Link

NA

💻 Code

A large codebase

🙁 Actual behavior

error TS2590: Expression produces a union type that is too complex to represent

🙂 Expected behavior

No type errors

Additional information about the issue

We have a build pipeline that uses typescript type checking with "incremental": true on our top level project.
We also have a tsconfig.tsbuildinfo generated at regular intervals from our master branch, and use it for ts caching in various branches in CI.

Ocassionally, we run into "error TS2590: Expression produces a union type that is too complex to represent", but it goes away once we clear/delete tsconfig.tsbuildinfo file. and re-run tsc/type-checker.

[RyanCavanaugh]

We need a way to repro this. You'll also need to try this on the most recent TS release (5.4) before we can investigate - it's very possible this was fixed since 4.9

[jayshah123]

Is there a way we can invoke TSC to print more debugging info on the offending types?
This will help us come up with a reproducible use case.
Also any relevant internal file where we can enable logging is fine.

[RyanCavanaugh]

We don't have any debugging flags like that. The best thing you can do is run tsc.js in a debugger with a breakpoint on the line that issues the error and inspect the call stack at tha tpoint

[jayshah123]

Will re-open after I have sufficient debugging info.