Tuple + Record Intersection Assignment Compatibility Inconsistency

TypeScript Version: 4.1.0-dev.20200824

Search Terms: tuple, object, intersection, type, assignment, coercion

Code

Here is the type that I'd like to use in an assignment:

type X = {example: "Field"} & number[];

The following produces TS error 2322.

const x: X = {
  ...[1, 2],
  example: "Field",
} as const;

If we update this example like so, the type error disappears:

- const x: X = {
+ const x = {
    ...[1, 2],
    example: "Field",
  } as const;

+ const y: X = x;

Expected behavior:

I would have expected the first assignment to not produce a type error. I'm wondering if this inconsistency (if that's the correct word for it) is an edge case, or by design? Apologies if this issue is unhelpful! Thank you!

Actual behavior:

Playground Link: https://www.typescriptlang.org/play?#code/HYQwtgpgzgDiDGEAEAhATgewNYWEg3gLABQSSALgJ4zIAaSAvARAB7gwA2EAXEgEQAxAJYQOAEz4BfJADIkwAK5gARhDQBtALoBuEiTLwMwKOSQte9JkVJkkAOgfqAjABokAJk0v9t1uy68giLifN420iBQSIbG5LrEknrEoJCwCMgA6hhoWFHWZFQ0SJbMbGCcPPzCohLScooqalrxPjEmZowEPmQOds5unmG2SH7lAVXBEkNIEVFtcUkGRu2UFp0s8ZJAA

Commencez par le TypeScript Playground lié et reproduisez les deux formes d’affectation présentées dans l’issue. Suivez le parcours de vérification des types pour les types intersection, les spreads de tableaux ou de tuples et les affectations de littéraux d’objet ; le travail est terminé lorsque le comportement est expliqué et que, s’il est confirmé qu’il s’agit d’un bug, un test de régression capture le résultat attendu.