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Exclude comparable relation from literal type relation optimization (#53419)

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This commit is contained in:
Anders Hejlsberg
2023-03-23 07:04:16 -07:00
committed by GitHub
parent 25550bd3d6
commit 37bafa539c
4 changed files with 187 additions and 2 deletions
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5
src/compiler/checker.ts
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@@ -20899,14 +20899,15 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
if (containsType(targetTypes, source)) {
return Ternary.True;
}
if (getObjectFlags(target) & ObjectFlags.PrimitiveUnion && !(source.flags & TypeFlags.EnumLiteral) && (
if (relation !== comparableRelation && getObjectFlags(target) & ObjectFlags.PrimitiveUnion && !(source.flags & TypeFlags.EnumLiteral) && (
source.flags & (TypeFlags.StringLiteral | TypeFlags.BooleanLiteral | TypeFlags.BigIntLiteral) ||
(relation === subtypeRelation || relation === strictSubtypeRelation) && source.flags & TypeFlags.NumberLiteral)) {
// When relating a literal type to a union of primitive types, we know the relation is false unless
// the union contains the base primitive type or the literal type in one of its fresh/regular forms.
// We exclude numeric literals for non-subtype relations because numeric literals are assignable to
// numeric enum literals with the same value. Similarly, we exclude enum literal types because
// identically named enum types are related (see isEmumTypeRelatedTo).
// identically named enum types are related (see isEnumTypeRelatedTo). We exclude the comparable
// relation in entirety because it needs to be checked in both directions.
const alternateForm = source === (source as StringLiteralType).regularType ? (source as StringLiteralType).freshType : (source as StringLiteralType).regularType;
const primitive = source.flags & TypeFlags.StringLiteral ? stringType :
source.flags & TypeFlags.NumberLiteral ? numberType :