microsoft / microsoft/TypeScript

TS2322 error in tsgo but not tsc

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#63,778 3 comments 0 reactions 1 assignee View on GitHub

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Since Aug 19, 2025.

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Description

## Steps to reproduce

With default compiler options:

```ts
enum E {
Foo,
Bar,
}
type A = { type: 'a'; e: E }
type B = { type: 'b' }
type C = A & { e: E.Bar }

function fn(v: A | B | C): A | B | C {
return { ...v, e: E.Foo }
}
```

## Behavior with `typescript@5.8`

Typechecks successfully.

## Behavior with `tsgo`

> index.ts:10:18 - error TS2322: Type 'E.Foo' is not assignable to type 'E.Bar'.

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