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5 commits

Author SHA1 Message Date
Anders Hejlsberg 82c02a7e42 Merge branch 'main' into fix44572 2021-09-09 09:18:22 -07:00
Anders Hejlsberg 813b04b083 Merge branch 'main' into fix44572 2021-08-29 16:57:31 -07:00
Anders Hejlsberg a1f82c12d7 Add regression test 2021-08-29 16:19:05 -07:00
Anders Hejlsberg 2d5ba1b49b Accept new baselines 2021-08-29 16:00:36 -07:00
Anders Hejlsberg 73fc830837 Fix variance computation logic 2021-08-29 16:00:24 -07:00
8 changed files with 445 additions and 14 deletions

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@ -12949,13 +12949,18 @@ namespace ts {
return result & ObjectFlags.PropagatingFlags;
}
function containsMarkerType(typeArguments: readonly Type[] | undefined) {
return some(typeArguments, t => t === markerSuperType || t === markerSubType || t === markerOtherType);
}
function createTypeReference(target: GenericType, typeArguments: readonly Type[] | undefined): TypeReference {
const id = getTypeListId(typeArguments);
let type = target.instantiations.get(id);
if (!type) {
type = createObjectType(ObjectFlags.Reference, target.symbol) as TypeReference;
target.instantiations.set(id, type);
type.objectFlags |= typeArguments ? getPropagatingFlagsOfTypes(typeArguments, /*excludeKinds*/ 0) : 0;
type.objectFlags |= (typeArguments ? getPropagatingFlagsOfTypes(typeArguments, /*excludeKinds*/ 0) : 0) |
(containsMarkerType(typeArguments) ? ObjectFlags.MarkerType : 0);
type.target = target;
type.resolvedTypeArguments = typeArguments;
}
@ -17484,7 +17489,9 @@ namespace ts {
if (source.flags !== target.flags) return false;
if (source.flags & TypeFlags.Singleton) return true;
}
if (source.flags & TypeFlags.Object && target.flags & TypeFlags.Object) {
// We skip the cache lookup shortcut when we're in a variance computation so the outofbandVarianceMarkerHandler
// will get called for cached results that are unreliable or unmeasurable.
if (source.flags & TypeFlags.Object && target.flags & TypeFlags.Object && !outofbandVarianceMarkerHandler) {
const related = relation.get(getRelationKey(source, target, IntersectionState.None, relation));
if (related !== undefined) {
return !!(related & RelationComparisonResult.Succeeded);
@ -18572,7 +18579,7 @@ namespace ts {
// the order in which things were checked.
if (source.flags & (TypeFlags.Object | TypeFlags.Conditional) && source.aliasSymbol &&
source.aliasTypeArguments && source.aliasSymbol === target.aliasSymbol &&
!(source.aliasTypeArgumentsContainsMarker || target.aliasTypeArgumentsContainsMarker)) {
!(containsMarkerType(source.aliasTypeArguments) || containsMarkerType(target.aliasTypeArguments))) {
const variances = getAliasVariances(source.aliasSymbol);
if (variances === emptyArray) {
return Ternary.Unknown;
@ -19828,18 +19835,14 @@ namespace ts {
// Return a type reference where the source type parameter is replaced with the target marker
// type, and flag the result as a marker type reference.
function getMarkerTypeReference(type: GenericType, source: TypeParameter, target: Type) {
const result = createTypeReference(type, map(type.typeParameters, t => t === source ? target : t));
result.objectFlags |= ObjectFlags.MarkerType;
return result;
return createTypeReference(type, map(type.typeParameters, t => t === source ? target : t));
}
function getAliasVariances(symbol: Symbol) {
const links = getSymbolLinks(symbol);
return getVariancesWorker(links.typeParameters, links, (_links, param, marker) => {
const type = getTypeAliasInstantiation(symbol, instantiateTypes(links.typeParameters!, makeUnaryTypeMapper(param, marker)));
type.aliasTypeArgumentsContainsMarker = true;
return type;
});
return getVariancesWorker(links.typeParameters, links, (_links, param, marker) =>
getTypeAliasInstantiation(symbol, instantiateTypes(links.typeParameters!, makeUnaryTypeMapper(param, marker)))
);
}
// Return an array containing the variance of each type parameter. The variance is effectively

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@ -5165,7 +5165,6 @@ namespace ts {
pattern?: DestructuringPattern; // Destructuring pattern represented by type (if any)
aliasSymbol?: Symbol; // Alias associated with type
aliasTypeArguments?: readonly Type[]; // Alias type arguments (if any)
/* @internal */ aliasTypeArgumentsContainsMarker?: boolean; // Alias type arguments (if any)
/* @internal */
permissiveInstantiation?: Type; // Instantiation with type parameters mapped to wildcard type
/* @internal */

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@ -0,0 +1,65 @@
tests/cases/compiler/checkOrderDependenceGenericAssignability.ts(24,1): error TS2322: Type 'Parent1<unknown>' is not assignable to type 'Parent1<string>'.
Type 'unknown' is not assignable to type 'string'.
tests/cases/compiler/checkOrderDependenceGenericAssignability.ts(51,1): error TS2322: Type 'Parent2<unknown>' is not assignable to type 'Parent2<string>'.
Type 'unknown' is not assignable to type 'string'.
==== tests/cases/compiler/checkOrderDependenceGenericAssignability.ts (2 errors) ====
// Repro from #44572 with interface types
interface Parent1<A> {
child: Child1<A>;
parent: Parent1<A>;
}
interface Child1<A, B = unknown> extends Parent1<A> {
readonly a: A;
// This field isn't necessary to the repro, but the
// type parameter is, so including it
readonly b: B;
}
function fn1<A>(inp: Child1<A>) {
// This assignability check defeats the later one
const a: Child1<unknown> = inp;
}
declare let pu1: Parent1<unknown>;
declare let ps1: Parent1<string>;
pu1 = ps1; // Ok
ps1 = pu1; // Error expected
~~~
!!! error TS2322: Type 'Parent1<unknown>' is not assignable to type 'Parent1<string>'.
!!! error TS2322: Type 'unknown' is not assignable to type 'string'.
// Repro from #44572 with aliased object types
type Parent2<A> = {
child: Child2<A>;
parent: Parent2<A>;
}
type Child2<A, B = unknown> = {
child: Child2<A>;
parent: Parent2<A>;
readonly a: A;
// This field isn't necessary to the repro, but the
// type parameter is, so including it
readonly b: B;
}
function fn2<A>(inp: Child2<A>) {
// This assignability check defeats the later one
const a: Child2<unknown> = inp;
}
declare let pu2: Parent2<unknown>;
declare let ps2: Parent2<string>;
pu2 = ps2; // Ok
ps2 = pu2; // Error expected
~~~
!!! error TS2322: Type 'Parent2<unknown>' is not assignable to type 'Parent2<string>'.
!!! error TS2322: Type 'unknown' is not assignable to type 'string'.

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@ -0,0 +1,69 @@
//// [checkOrderDependenceGenericAssignability.ts]
// Repro from #44572 with interface types
interface Parent1<A> {
child: Child1<A>;
parent: Parent1<A>;
}
interface Child1<A, B = unknown> extends Parent1<A> {
readonly a: A;
// This field isn't necessary to the repro, but the
// type parameter is, so including it
readonly b: B;
}
function fn1<A>(inp: Child1<A>) {
// This assignability check defeats the later one
const a: Child1<unknown> = inp;
}
declare let pu1: Parent1<unknown>;
declare let ps1: Parent1<string>;
pu1 = ps1; // Ok
ps1 = pu1; // Error expected
// Repro from #44572 with aliased object types
type Parent2<A> = {
child: Child2<A>;
parent: Parent2<A>;
}
type Child2<A, B = unknown> = {
child: Child2<A>;
parent: Parent2<A>;
readonly a: A;
// This field isn't necessary to the repro, but the
// type parameter is, so including it
readonly b: B;
}
function fn2<A>(inp: Child2<A>) {
// This assignability check defeats the later one
const a: Child2<unknown> = inp;
}
declare let pu2: Parent2<unknown>;
declare let ps2: Parent2<string>;
pu2 = ps2; // Ok
ps2 = pu2; // Error expected
//// [checkOrderDependenceGenericAssignability.js]
"use strict";
// Repro from #44572 with interface types
function fn1(inp) {
// This assignability check defeats the later one
var a = inp;
}
pu1 = ps1; // Ok
ps1 = pu1; // Error expected
function fn2(inp) {
// This assignability check defeats the later one
var a = inp;
}
pu2 = ps2; // Ok
ps2 = pu2; // Error expected

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@ -0,0 +1,139 @@
=== tests/cases/compiler/checkOrderDependenceGenericAssignability.ts ===
// Repro from #44572 with interface types
interface Parent1<A> {
>Parent1 : Symbol(Parent1, Decl(checkOrderDependenceGenericAssignability.ts, 0, 0))
>A : Symbol(A, Decl(checkOrderDependenceGenericAssignability.ts, 2, 18))
child: Child1<A>;
>child : Symbol(Parent1.child, Decl(checkOrderDependenceGenericAssignability.ts, 2, 22))
>Child1 : Symbol(Child1, Decl(checkOrderDependenceGenericAssignability.ts, 5, 1))
>A : Symbol(A, Decl(checkOrderDependenceGenericAssignability.ts, 2, 18))
parent: Parent1<A>;
>parent : Symbol(Parent1.parent, Decl(checkOrderDependenceGenericAssignability.ts, 3, 21))
>Parent1 : Symbol(Parent1, Decl(checkOrderDependenceGenericAssignability.ts, 0, 0))
>A : Symbol(A, Decl(checkOrderDependenceGenericAssignability.ts, 2, 18))
}
interface Child1<A, B = unknown> extends Parent1<A> {
>Child1 : Symbol(Child1, Decl(checkOrderDependenceGenericAssignability.ts, 5, 1))
>A : Symbol(A, Decl(checkOrderDependenceGenericAssignability.ts, 7, 17))
>B : Symbol(B, Decl(checkOrderDependenceGenericAssignability.ts, 7, 19))
>Parent1 : Symbol(Parent1, Decl(checkOrderDependenceGenericAssignability.ts, 0, 0))
>A : Symbol(A, Decl(checkOrderDependenceGenericAssignability.ts, 7, 17))
readonly a: A;
>a : Symbol(Child1.a, Decl(checkOrderDependenceGenericAssignability.ts, 7, 53))
>A : Symbol(A, Decl(checkOrderDependenceGenericAssignability.ts, 7, 17))
// This field isn't necessary to the repro, but the
// type parameter is, so including it
readonly b: B;
>b : Symbol(Child1.b, Decl(checkOrderDependenceGenericAssignability.ts, 8, 18))
>B : Symbol(B, Decl(checkOrderDependenceGenericAssignability.ts, 7, 19))
}
function fn1<A>(inp: Child1<A>) {
>fn1 : Symbol(fn1, Decl(checkOrderDependenceGenericAssignability.ts, 12, 1))
>A : Symbol(A, Decl(checkOrderDependenceGenericAssignability.ts, 14, 13))
>inp : Symbol(inp, Decl(checkOrderDependenceGenericAssignability.ts, 14, 16))
>Child1 : Symbol(Child1, Decl(checkOrderDependenceGenericAssignability.ts, 5, 1))
>A : Symbol(A, Decl(checkOrderDependenceGenericAssignability.ts, 14, 13))
// This assignability check defeats the later one
const a: Child1<unknown> = inp;
>a : Symbol(a, Decl(checkOrderDependenceGenericAssignability.ts, 16, 9))
>Child1 : Symbol(Child1, Decl(checkOrderDependenceGenericAssignability.ts, 5, 1))
>inp : Symbol(inp, Decl(checkOrderDependenceGenericAssignability.ts, 14, 16))
}
declare let pu1: Parent1<unknown>;
>pu1 : Symbol(pu1, Decl(checkOrderDependenceGenericAssignability.ts, 19, 11))
>Parent1 : Symbol(Parent1, Decl(checkOrderDependenceGenericAssignability.ts, 0, 0))
declare let ps1: Parent1<string>;
>ps1 : Symbol(ps1, Decl(checkOrderDependenceGenericAssignability.ts, 20, 11))
>Parent1 : Symbol(Parent1, Decl(checkOrderDependenceGenericAssignability.ts, 0, 0))
pu1 = ps1; // Ok
>pu1 : Symbol(pu1, Decl(checkOrderDependenceGenericAssignability.ts, 19, 11))
>ps1 : Symbol(ps1, Decl(checkOrderDependenceGenericAssignability.ts, 20, 11))
ps1 = pu1; // Error expected
>ps1 : Symbol(ps1, Decl(checkOrderDependenceGenericAssignability.ts, 20, 11))
>pu1 : Symbol(pu1, Decl(checkOrderDependenceGenericAssignability.ts, 19, 11))
// Repro from #44572 with aliased object types
type Parent2<A> = {
>Parent2 : Symbol(Parent2, Decl(checkOrderDependenceGenericAssignability.ts, 23, 10))
>A : Symbol(A, Decl(checkOrderDependenceGenericAssignability.ts, 27, 13))
child: Child2<A>;
>child : Symbol(child, Decl(checkOrderDependenceGenericAssignability.ts, 27, 19))
>Child2 : Symbol(Child2, Decl(checkOrderDependenceGenericAssignability.ts, 30, 1))
>A : Symbol(A, Decl(checkOrderDependenceGenericAssignability.ts, 27, 13))
parent: Parent2<A>;
>parent : Symbol(parent, Decl(checkOrderDependenceGenericAssignability.ts, 28, 21))
>Parent2 : Symbol(Parent2, Decl(checkOrderDependenceGenericAssignability.ts, 23, 10))
>A : Symbol(A, Decl(checkOrderDependenceGenericAssignability.ts, 27, 13))
}
type Child2<A, B = unknown> = {
>Child2 : Symbol(Child2, Decl(checkOrderDependenceGenericAssignability.ts, 30, 1))
>A : Symbol(A, Decl(checkOrderDependenceGenericAssignability.ts, 32, 12))
>B : Symbol(B, Decl(checkOrderDependenceGenericAssignability.ts, 32, 14))
child: Child2<A>;
>child : Symbol(child, Decl(checkOrderDependenceGenericAssignability.ts, 32, 31))
>Child2 : Symbol(Child2, Decl(checkOrderDependenceGenericAssignability.ts, 30, 1))
>A : Symbol(A, Decl(checkOrderDependenceGenericAssignability.ts, 32, 12))
parent: Parent2<A>;
>parent : Symbol(parent, Decl(checkOrderDependenceGenericAssignability.ts, 33, 21))
>Parent2 : Symbol(Parent2, Decl(checkOrderDependenceGenericAssignability.ts, 23, 10))
>A : Symbol(A, Decl(checkOrderDependenceGenericAssignability.ts, 32, 12))
readonly a: A;
>a : Symbol(a, Decl(checkOrderDependenceGenericAssignability.ts, 34, 23))
>A : Symbol(A, Decl(checkOrderDependenceGenericAssignability.ts, 32, 12))
// This field isn't necessary to the repro, but the
// type parameter is, so including it
readonly b: B;
>b : Symbol(b, Decl(checkOrderDependenceGenericAssignability.ts, 35, 18))
>B : Symbol(B, Decl(checkOrderDependenceGenericAssignability.ts, 32, 14))
}
function fn2<A>(inp: Child2<A>) {
>fn2 : Symbol(fn2, Decl(checkOrderDependenceGenericAssignability.ts, 39, 1))
>A : Symbol(A, Decl(checkOrderDependenceGenericAssignability.ts, 41, 13))
>inp : Symbol(inp, Decl(checkOrderDependenceGenericAssignability.ts, 41, 16))
>Child2 : Symbol(Child2, Decl(checkOrderDependenceGenericAssignability.ts, 30, 1))
>A : Symbol(A, Decl(checkOrderDependenceGenericAssignability.ts, 41, 13))
// This assignability check defeats the later one
const a: Child2<unknown> = inp;
>a : Symbol(a, Decl(checkOrderDependenceGenericAssignability.ts, 43, 9))
>Child2 : Symbol(Child2, Decl(checkOrderDependenceGenericAssignability.ts, 30, 1))
>inp : Symbol(inp, Decl(checkOrderDependenceGenericAssignability.ts, 41, 16))
}
declare let pu2: Parent2<unknown>;
>pu2 : Symbol(pu2, Decl(checkOrderDependenceGenericAssignability.ts, 46, 11))
>Parent2 : Symbol(Parent2, Decl(checkOrderDependenceGenericAssignability.ts, 23, 10))
declare let ps2: Parent2<string>;
>ps2 : Symbol(ps2, Decl(checkOrderDependenceGenericAssignability.ts, 47, 11))
>Parent2 : Symbol(Parent2, Decl(checkOrderDependenceGenericAssignability.ts, 23, 10))
pu2 = ps2; // Ok
>pu2 : Symbol(pu2, Decl(checkOrderDependenceGenericAssignability.ts, 46, 11))
>ps2 : Symbol(ps2, Decl(checkOrderDependenceGenericAssignability.ts, 47, 11))
ps2 = pu2; // Error expected
>ps2 : Symbol(ps2, Decl(checkOrderDependenceGenericAssignability.ts, 47, 11))
>pu2 : Symbol(pu2, Decl(checkOrderDependenceGenericAssignability.ts, 46, 11))

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@ -0,0 +1,103 @@
=== tests/cases/compiler/checkOrderDependenceGenericAssignability.ts ===
// Repro from #44572 with interface types
interface Parent1<A> {
child: Child1<A>;
>child : Child1<A, unknown>
parent: Parent1<A>;
>parent : Parent1<A>
}
interface Child1<A, B = unknown> extends Parent1<A> {
readonly a: A;
>a : A
// This field isn't necessary to the repro, but the
// type parameter is, so including it
readonly b: B;
>b : B
}
function fn1<A>(inp: Child1<A>) {
>fn1 : <A>(inp: Child1<A>) => void
>inp : Child1<A, unknown>
// This assignability check defeats the later one
const a: Child1<unknown> = inp;
>a : Child1<unknown, unknown>
>inp : Child1<A, unknown>
}
declare let pu1: Parent1<unknown>;
>pu1 : Parent1<unknown>
declare let ps1: Parent1<string>;
>ps1 : Parent1<string>
pu1 = ps1; // Ok
>pu1 = ps1 : Parent1<string>
>pu1 : Parent1<unknown>
>ps1 : Parent1<string>
ps1 = pu1; // Error expected
>ps1 = pu1 : Parent1<unknown>
>ps1 : Parent1<string>
>pu1 : Parent1<unknown>
// Repro from #44572 with aliased object types
type Parent2<A> = {
>Parent2 : Parent2<A>
child: Child2<A>;
>child : Child2<A, unknown>
parent: Parent2<A>;
>parent : Parent2<A>
}
type Child2<A, B = unknown> = {
>Child2 : Child2<A, B>
child: Child2<A>;
>child : Child2<A, unknown>
parent: Parent2<A>;
>parent : Parent2<A>
readonly a: A;
>a : A
// This field isn't necessary to the repro, but the
// type parameter is, so including it
readonly b: B;
>b : B
}
function fn2<A>(inp: Child2<A>) {
>fn2 : <A>(inp: Child2<A>) => void
>inp : Child2<A, unknown>
// This assignability check defeats the later one
const a: Child2<unknown> = inp;
>a : Child2<unknown, unknown>
>inp : Child2<A, unknown>
}
declare let pu2: Parent2<unknown>;
>pu2 : Parent2<unknown>
declare let ps2: Parent2<string>;
>ps2 : Parent2<string>
pu2 = ps2; // Ok
>pu2 = ps2 : Parent2<string>
>pu2 : Parent2<unknown>
>ps2 : Parent2<string>
ps2 = pu2; // Error expected
>ps2 = pu2 : Parent2<unknown>
>ps2 : Parent2<string>
>pu2 : Parent2<unknown>

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@ -5,7 +5,7 @@ tests/cases/compiler/flatArrayNoExcessiveStackDepth.ts(20,5): error TS2322: Type
Type 'unknown' is not assignable to type 'Arr extends readonly (infer InnerArr)[] ? FlatArray<InnerArr, [-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][D]> : Arr'.
Type 'FlatArray<InnerArr, 0 | 2 | 1 | -1 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20>' is not assignable to type 'FlatArray<InnerArr, [-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][D]>'.
Type 'InnerArr' is not assignable to type 'FlatArray<InnerArr, [-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][D]>'.
Type 'InnerArr' is not assignable to type '(InnerArr extends readonly (infer InnerArr)[] ? FlatArray<InnerArr, [-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][[-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][D]]> : InnerArr) & InnerArr'.
Type 'InnerArr' is not assignable to type 'InnerArr & (InnerArr extends readonly (infer InnerArr)[] ? FlatArray<InnerArr, [-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][[-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][D]]> : InnerArr)'.
Type 'InnerArr' is not assignable to type 'InnerArr extends readonly (infer InnerArr)[] ? FlatArray<InnerArr, [-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][[-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][D]]> : InnerArr'.
@ -38,7 +38,7 @@ tests/cases/compiler/flatArrayNoExcessiveStackDepth.ts(20,5): error TS2322: Type
!!! error TS2322: Type 'unknown' is not assignable to type 'Arr extends readonly (infer InnerArr)[] ? FlatArray<InnerArr, [-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][D]> : Arr'.
!!! error TS2322: Type 'FlatArray<InnerArr, 0 | 2 | 1 | -1 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20>' is not assignable to type 'FlatArray<InnerArr, [-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][D]>'.
!!! error TS2322: Type 'InnerArr' is not assignable to type 'FlatArray<InnerArr, [-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][D]>'.
!!! error TS2322: Type 'InnerArr' is not assignable to type '(InnerArr extends readonly (infer InnerArr)[] ? FlatArray<InnerArr, [-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][[-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][D]]> : InnerArr) & InnerArr'.
!!! error TS2322: Type 'InnerArr' is not assignable to type 'InnerArr & (InnerArr extends readonly (infer InnerArr)[] ? FlatArray<InnerArr, [-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][[-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][D]]> : InnerArr)'.
!!! error TS2322: Type 'InnerArr' is not assignable to type 'InnerArr extends readonly (infer InnerArr)[] ? FlatArray<InnerArr, [-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][[-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][D]]> : InnerArr'.
}

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@ -0,0 +1,53 @@
// @strict: true
// Repro from #44572 with interface types
interface Parent1<A> {
child: Child1<A>;
parent: Parent1<A>;
}
interface Child1<A, B = unknown> extends Parent1<A> {
readonly a: A;
// This field isn't necessary to the repro, but the
// type parameter is, so including it
readonly b: B;
}
function fn1<A>(inp: Child1<A>) {
// This assignability check defeats the later one
const a: Child1<unknown> = inp;
}
declare let pu1: Parent1<unknown>;
declare let ps1: Parent1<string>;
pu1 = ps1; // Ok
ps1 = pu1; // Error expected
// Repro from #44572 with aliased object types
type Parent2<A> = {
child: Child2<A>;
parent: Parent2<A>;
}
type Child2<A, B = unknown> = {
child: Child2<A>;
parent: Parent2<A>;
readonly a: A;
// This field isn't necessary to the repro, but the
// type parameter is, so including it
readonly b: B;
}
function fn2<A>(inp: Child2<A>) {
// This assignability check defeats the later one
const a: Child2<unknown> = inp;
}
declare let pu2: Parent2<unknown>;
declare let ps2: Parent2<string>;
pu2 = ps2; // Ok
ps2 = pu2; // Error expected