Too wide diagnostic with array spread

🔎 Search Terms

array spread, diagnostics

🕗 Version & Regression Information

• This is the behavior in every version I tried and I have reviewed the FAQ

⏯ Playground Link

https://www.typescriptlang.org/play?ts=5.4.4#code/C4TwDgpgBAggRgYygXigIgIZqgH3XbPNBNAbgChyEB7AOwGdgoMAnFjEARgC5ZEBtALooo-TGgA0+NIIpU6jZmw4AmXvARCR-clD1QAdEdbsuE3fvFSLetAXP70AE0nlBQA

💻 Code

type Abc = "a" | "b" | "c";

const array1: Abc[] = ["a", "b"];

const array2: Abc[] = [
    ...array1,
    "a", 
    "b",
    "d",
]

🙁 Actual behavior

The whole contents of array2 is highlighted in red.

🙂 Expected behavior

Only the "d" should be highlighted in red, as it is the only incorrect part of array2. Note that if we remove the spread ...array1, then it works as expected.

Additional information about the issue

With more complicated types/data, this bug can make it pretty hard to diagnose where the problem is.

Commencez par la reproduction liée dans TypeScript Playground et par l’exemple d’array-spread de l’issue. Suivez la manière dont les diagnostics sont produits pour le littéral de tableau, puis vérifiez que seul l’élément "d" est mis en évidence, tandis que le spread et les éléments valides ne le sont pas.