Treatment of recursive tuples that utilize type spread.

TypeScript Version: 4.0.2

Search Terms: spread tuple in recursive tuple type

Code

I'm trying to model a type that could evaluate to any of the following:

["list", "of", "Post"];
["list", "of", "list", "of", "Post"];
["list", "of", "list", "of", "list", "of", "Post"];
// ... could go on

The following approach produces a circularity error, even though tuple types are circularity-capable since 3.7 :/

type Nested = ["list", "of", ...(["Post"] | Nested)];

Expected behavior:

To be able to type-check the following (for example):

const nested: Nested = ["list", "of", "list", "of", "Post"];

Actual behavior:

Circularity error.

Any help would be greatly appreciated! Thank you!

ソースファイルもテストも指定されていません。まず、提供されている TypeScript 4.0.2 の再帰的タプルの例で循環性エラーを再現し、次に、再帰的タプル型と type spreads の type-checker における処理を追跡してください。サンプル宣言とネストされた値が循環性エラーなしで型チェックされ、適切なコンパイラテスト領域にカバレッジが追加されていれば完了です。