Don't add special behavior for tuples.

DanielRosenwasser · web-flow · commit f01ae16e6589 · 2021-10-22T22:39:28.000Z
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -16516,7 +16516,7 @@ namespace ts {
                         if (t.flags & (TypeFlags.AnyOrUnknown | TypeFlags.InstantiableNonPrimitive | TypeFlags.Object | TypeFlags.Intersection) && t !== wildcardType && !isErrorType(t)) {
                             if (!type.declaration.nameType) {
                                 let constraint;
-                                if (isArrayType(t) || (t.flags & TypeFlags.Any) && (constraint = getConstraintOfTypeParameter(typeVariable)) && everyType(constraint, or(isArrayType, isTupleType))) {
+                                if (isArrayType(t) || (t.flags & TypeFlags.Any) && (constraint = getConstraintOfTypeParameter(typeVariable)) && everyType(constraint, isArrayType)) {
                                     return instantiateMappedArrayType(t, type, prependTypeMapping(typeVariable, t, mapper));
                                 }
                                 if (isGenericTupleType(t)) {

Original file line number	Diff line number	Diff line change
`@@ -16516,7 +16516,7 @@ namespace ts {`
`16516`	`16516`	`if (t.flags & (TypeFlags.AnyOrUnknown \| TypeFlags.InstantiableNonPrimitive \| TypeFlags.Object \| TypeFlags.Intersection) && t !== wildcardType && !isErrorType(t)) {`
`16517`	`16517`	`if (!type.declaration.nameType) {`
`16518`	`16518`	`let constraint;`
`16519`		`- if (isArrayType(t) \|\| (t.flags & TypeFlags.Any) && (constraint = getConstraintOfTypeParameter(typeVariable)) && everyType(constraint, or(isArrayType, isTupleType))) {`
	`16519`	`+ if (isArrayType(t) \|\| (t.flags & TypeFlags.Any) && (constraint = getConstraintOfTypeParameter(typeVariable)) && everyType(constraint, isArrayType)) {`
`16520`	`16520`	`return instantiateMappedArrayType(t, type, prependTypeMapping(typeVariable, t, mapper));`
`16521`	`16521`	`}`
`16522`	`16522`	`if (isGenericTupleType(t)) {`