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Merged
ahejlsberg merged 5 commits into from
Jan 11, 2021
Merged

Support re-aliasing of type alias instantiations #42284

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a4a47db
New aliases for type alias instantiations
ahejlsberg Jan 9, 2021
0c6dfb7
New aliases for conditional, mapped, and anonymous object type instan…
ahejlsberg Jan 9, 2021
54da2a4
Accept new baselines
ahejlsberg Jan 9, 2021
1b0d12e
Fix issues with re-aliasing
ahejlsberg Jan 11, 2021
8ac7030
Accept new baselines
ahejlsberg Jan 11, 2021
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@ahejlsberg
ahejlsberg committed Jan 11, 2021
commit 8ac70306225ea6e15d487c92581690644b09a458
44 changes: 32 additions & 12 deletions tests/baselines/reference/conditionalTypes1.errors.txt
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Expand Up @@ -13,14 +13,24 @@ tests/cases/conformance/types/conditional/conditionalTypes1.ts(29,5): error TS23
tests/cases/conformance/types/conditional/conditionalTypes1.ts(30,9): error TS2322: Type 'T["x"]' is not assignable to type 'string'.
Type 'string | undefined' is not assignable to type 'string'.
Type 'undefined' is not assignable to type 'string'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(103,5): error TS2322: Type 'Pick<T, FunctionPropertyNames<T>>' is not assignable to type 'T'.
'T' could be instantiated with an arbitrary type which could be unrelated to 'Pick<T, FunctionPropertyNames<T>>'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(104,5): error TS2322: Type 'Pick<T, NonFunctionPropertyNames<T>>' is not assignable to type 'T'.
'T' could be instantiated with an arbitrary type which could be unrelated to 'Pick<T, NonFunctionPropertyNames<T>>'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(106,5): error TS2322: Type 'Pick<T, NonFunctionPropertyNames<T>>' is not assignable to type 'Pick<T, FunctionPropertyNames<T>>'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(103,5): error TS2322: Type 'FunctionProperties<T>' is not assignable to type 'T'.
'T' could be instantiated with an arbitrary type which could be unrelated to 'FunctionProperties<T>'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(104,5): error TS2322: Type 'NonFunctionProperties<T>' is not assignable to type 'T'.
'T' could be instantiated with an arbitrary type which could be unrelated to 'NonFunctionProperties<T>'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(106,5): error TS2322: Type 'NonFunctionProperties<T>' is not assignable to type 'FunctionProperties<T>'.
Type 'FunctionPropertyNames<T>' is not assignable to type 'NonFunctionPropertyNames<T>'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(108,5): error TS2322: Type 'Pick<T, FunctionPropertyNames<T>>' is not assignable to type 'Pick<T, NonFunctionPropertyNames<T>>'.
Type 'keyof T' is not assignable to type 'T[keyof T] extends Function ? never : keyof T'.
Type 'string | number | symbol' is not assignable to type 'T[keyof T] extends Function ? never : keyof T'.
Type 'string' is not assignable to type 'T[keyof T] extends Function ? never : keyof T'.
Type 'keyof T' is not assignable to type 'never'.
Type 'string | number | symbol' is not assignable to type 'never'.
Type 'string' is not assignable to type 'never'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(108,5): error TS2322: Type 'FunctionProperties<T>' is not assignable to type 'NonFunctionProperties<T>'.
Type 'NonFunctionPropertyNames<T>' is not assignable to type 'FunctionPropertyNames<T>'.
Type 'keyof T' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
Type 'string | number | symbol' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
Type 'string' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
Type 'keyof T' is not assignable to type 'never'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(114,5): error TS2322: Type 'keyof T' is not assignable to type 'FunctionPropertyNames<T>'.
Type 'string | number | symbol' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
Type 'string' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
Expand Down Expand Up @@ -185,22 +195,32 @@ tests/cases/conformance/types/conditional/conditionalTypes1.ts(288,43): error TS
function f7<T>(x: T, y: FunctionProperties<T>, z: NonFunctionProperties<T>) {
x = y; // Error
~
!!! error TS2322: Type 'Pick<T, FunctionPropertyNames<T>>' is not assignable to type 'T'.
!!! error TS2322: 'T' could be instantiated with an arbitrary type which could be unrelated to 'Pick<T, FunctionPropertyNames<T>>'.
!!! error TS2322: Type 'FunctionProperties<T>' is not assignable to type 'T'.
!!! error TS2322: 'T' could be instantiated with an arbitrary type which could be unrelated to 'FunctionProperties<T>'.
x = z; // Error
~
!!! error TS2322: Type 'Pick<T, NonFunctionPropertyNames<T>>' is not assignable to type 'T'.
!!! error TS2322: 'T' could be instantiated with an arbitrary type which could be unrelated to 'Pick<T, NonFunctionPropertyNames<T>>'.
!!! error TS2322: Type 'NonFunctionProperties<T>' is not assignable to type 'T'.
!!! error TS2322: 'T' could be instantiated with an arbitrary type which could be unrelated to 'NonFunctionProperties<T>'.
y = x;
y = z; // Error
~
!!! error TS2322: Type 'Pick<T, NonFunctionPropertyNames<T>>' is not assignable to type 'Pick<T, FunctionPropertyNames<T>>'.
!!! error TS2322: Type 'NonFunctionProperties<T>' is not assignable to type 'FunctionProperties<T>'.
!!! error TS2322: Type 'FunctionPropertyNames<T>' is not assignable to type 'NonFunctionPropertyNames<T>'.
!!! error TS2322: Type 'keyof T' is not assignable to type 'T[keyof T] extends Function ? never : keyof T'.
!!! error TS2322: Type 'string | number | symbol' is not assignable to type 'T[keyof T] extends Function ? never : keyof T'.
!!! error TS2322: Type 'string' is not assignable to type 'T[keyof T] extends Function ? never : keyof T'.
!!! error TS2322: Type 'keyof T' is not assignable to type 'never'.
!!! error TS2322: Type 'string | number | symbol' is not assignable to type 'never'.
!!! error TS2322: Type 'string' is not assignable to type 'never'.
Comment on lines +209 to +214
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@DanielRosenwasser DanielRosenwasser Jan 11, 2021

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Why's this happening? What was avoiding the elaboration before?

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@DanielRosenwasser DanielRosenwasser Jan 11, 2021

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Sounds like we can't avoid re-elaboration based on type IDs

z = x;
z = y; // Error
~
!!! error TS2322: Type 'Pick<T, FunctionPropertyNames<T>>' is not assignable to type 'Pick<T, NonFunctionPropertyNames<T>>'.
!!! error TS2322: Type 'FunctionProperties<T>' is not assignable to type 'NonFunctionProperties<T>'.
!!! error TS2322: Type 'NonFunctionPropertyNames<T>' is not assignable to type 'FunctionPropertyNames<T>'.
!!! error TS2322: Type 'keyof T' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
!!! error TS2322: Type 'string | number | symbol' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
!!! error TS2322: Type 'string' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
!!! error TS2322: Type 'keyof T' is not assignable to type 'never'.
}

function f8<T>(x: keyof T, y: FunctionPropertyNames<T>, z: NonFunctionPropertyNames<T>) {
Expand Down
28 changes: 14 additions & 14 deletions tests/baselines/reference/conditionalTypes1.types
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Expand Up @@ -247,38 +247,38 @@ type T31 = NonFunctionProperties<Part>;
function f7<T>(x: T, y: FunctionProperties<T>, z: NonFunctionProperties<T>) {
>f7 : <T>(x: T, y: FunctionProperties<T>, z: NonFunctionProperties<T>) => void
>x : T
>y : Pick<T, FunctionPropertyNames<T>>
>z : Pick<T, NonFunctionPropertyNames<T>>
>y : FunctionProperties<T>
>z : NonFunctionProperties<T>

x = y; // Error
>x = y : Pick<T, FunctionPropertyNames<T>>
>x = y : FunctionProperties<T>
>x : T
>y : Pick<T, FunctionPropertyNames<T>>
>y : FunctionProperties<T>

x = z; // Error
>x = z : Pick<T, NonFunctionPropertyNames<T>>
>x = z : NonFunctionProperties<T>
>x : T
>z : Pick<T, NonFunctionPropertyNames<T>>
>z : NonFunctionProperties<T>

y = x;
>y = x : T
>y : Pick<T, FunctionPropertyNames<T>>
>y : FunctionProperties<T>
>x : T

y = z; // Error
>y = z : Pick<T, NonFunctionPropertyNames<T>>
>y : Pick<T, FunctionPropertyNames<T>>
>z : Pick<T, NonFunctionPropertyNames<T>>
>y = z : NonFunctionProperties<T>
>y : FunctionProperties<T>
>z : NonFunctionProperties<T>

z = x;
>z = x : T
>z : Pick<T, NonFunctionPropertyNames<T>>
>z : NonFunctionProperties<T>
>x : T

z = y; // Error
>z = y : Pick<T, FunctionPropertyNames<T>>
>z : Pick<T, NonFunctionPropertyNames<T>>
>y : Pick<T, FunctionPropertyNames<T>>
>z = y : FunctionProperties<T>
>z : NonFunctionProperties<T>
>y : FunctionProperties<T>
}

function f8<T>(x: keyof T, y: FunctionPropertyNames<T>, z: NonFunctionPropertyNames<T>) {
Expand Down
2 changes: 1 addition & 1 deletion tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters1.types
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Expand Up @@ -8,6 +8,6 @@ export type Foo<Y> = Bar<any, Y>;
export const y = (x: Foo<string>) => 1
>y : (x: Foo<string>) => number
>(x: Foo<string>) => 1 : (x: Foo<string>) => number
>x : Bar<any, string>
>x : Foo<string>
>1 : 1

2 changes: 1 addition & 1 deletion tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters2.types
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Expand Up @@ -11,6 +11,6 @@ export type Baa<Y> = Baz<boolean, Y>;
export const y = (x: Baa<number>) => 1
>y : (x: Baa<number>) => number
>(x: Baa<number>) => 1 : (x: Baa<number>) => number
>x : Bar<boolean, string, number>
>x : Baa<number>
>1 : 1

2 changes: 1 addition & 1 deletion tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters4.js
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Expand Up @@ -20,4 +20,4 @@ declare type Foo<T, Y> = {
foo<U, J>(): Foo<U, J>;
};
declare type SubFoo<R> = Foo<string, R>;
declare function foo(): Foo<string, number>;
declare function foo(): SubFoo<number>;
4 changes: 2 additions & 2 deletions tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters4.types
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Expand Up @@ -10,10 +10,10 @@ type SubFoo<R> = Foo<string, R>;
>SubFoo : SubFoo<R>

function foo() {
>foo : () => Foo<string, number>
>foo : () => SubFoo<number>

return {} as SubFoo<number>;
>{} as SubFoo<number> : Foo<string, number>
>{} as SubFoo<number> : SubFoo<number>
>{} : {}
}

4 changes: 2 additions & 2 deletions tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters5.types
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Expand Up @@ -10,10 +10,10 @@ export type SubFoo<R> = Foo<string, R>;
>SubFoo : SubFoo<R>

function foo() {
>foo : () => Foo<string, number>
>foo : () => SubFoo<number>

return {} as SubFoo<number>;
>{} as SubFoo<number> : Foo<string, number>
>{} as SubFoo<number> : SubFoo<number>
>{} : {}
}

2 changes: 1 addition & 1 deletion tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters6.js
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Expand Up @@ -20,4 +20,4 @@ declare type Foo<T, Y> = {
foo<U, J>(): Foo<U, J>;
};
declare type SubFoo<R, S> = Foo<S, R>;
declare function foo(): Foo<string, number>;
declare function foo(): SubFoo<number, string>;
4 changes: 2 additions & 2 deletions tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters6.types
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Expand Up @@ -10,10 +10,10 @@ type SubFoo<R, S> = Foo<S, R>;
>SubFoo : SubFoo<R, S>

function foo() {
>foo : () => Foo<string, number>
>foo : () => SubFoo<number, string>

return {} as SubFoo<number, string>;
>{} as SubFoo<number, string> : Foo<string, number>
>{} as SubFoo<number, string> : SubFoo<number, string>
>{} : {}
}

8 changes: 4 additions & 4 deletions tests/baselines/reference/discriminantPropertyCheck.types
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Expand Up @@ -464,18 +464,18 @@ type TypeBar2 = { type: BarEnum.bar2 };

function func3(value: Partial<UnionOfBar>) {
>func3 : (value: Partial<UnionOfBar>) => void
>value : Partial<TypeBar1> | Partial<TypeBar2>
>value : Partial<UnionOfBar>

if (value.type !== undefined) {
>value.type !== undefined : boolean
>value.type : BarEnum | undefined
>value : Partial<TypeBar1> | Partial<TypeBar2>
>value : Partial<UnionOfBar>
>type : BarEnum | undefined
>undefined : undefined

switch (value.type) {
>value.type : BarEnum
>value : Partial<TypeBar1> | Partial<TypeBar2>
>value : Partial<UnionOfBar>
>type : BarEnum

case BarEnum.bar1:
Expand All @@ -495,7 +495,7 @@ function func3(value: Partial<UnionOfBar>) {
>never(value.type) : never
>never : (value: never) => never
>value.type : never
>value : Partial<TypeBar1> | Partial<TypeBar2>
>value : Partial<UnionOfBar>
>type : never
}
}
Expand Down
4 changes: 2 additions & 2 deletions tests/baselines/reference/emptyObjectNotSubtypeOfIndexSignatureContainingObject1.types
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Expand Up @@ -37,7 +37,7 @@ function mapValues<T, TResult>(
>null : null

callback: DictionaryIterator<T, TResult>
>callback : ObjectIterator<Dictionary<T>, TResult>
>callback : DictionaryIterator<T, TResult>

): Dictionary<TResult> {
return null as any;
Expand Down Expand Up @@ -73,7 +73,7 @@ export function fooToBar(
>null : null
>{} : {}
>mapValues(foos, f => f.foo) : Dictionary<string>
>mapValues : <T, TResult>(obj: Dictionary<T> | NumericDictionary<T>, callback: ObjectIterator<Dictionary<T>, TResult>) => Dictionary<TResult>
>mapValues : <T, TResult>(obj: Dictionary<T> | NumericDictionary<T>, callback: DictionaryIterator<T, TResult>) => Dictionary<TResult>
>foos : Record<string, Foo>
>f => f.foo : (f: Foo) => string
>f : Foo
Expand Down
6 changes: 3 additions & 3 deletions tests/baselines/reference/emptyObjectNotSubtypeOfIndexSignatureContainingObject2.types
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Expand Up @@ -37,7 +37,7 @@ function mapValues<T, TResult>(
>null : null

callback: DictionaryIterator<T, TResult>
>callback : ObjectIterator<Dictionary<T>, TResult>
>callback : DictionaryIterator<T, TResult>

): Dictionary<TResult> {
return null as any;
Expand Down Expand Up @@ -68,7 +68,7 @@ export function fooToBar(
const wat = mapValues(foos, f => f.foo);
>wat : Dictionary<string>
>mapValues(foos, f => f.foo) : Dictionary<string>
>mapValues : <T, TResult>(obj: Dictionary<T> | NumericDictionary<T>, callback: ObjectIterator<Dictionary<T>, TResult>) => Dictionary<TResult>
>mapValues : <T, TResult>(obj: Dictionary<T> | NumericDictionary<T>, callback: DictionaryIterator<T, TResult>) => Dictionary<TResult>
>foos : Record<string, Foo>
>f => f.foo : (f: Foo) => string
>f : Foo
Expand All @@ -84,7 +84,7 @@ export function fooToBar(
>null : null
>{} : {}
>mapValues(foos, f => f.foo) : Dictionary<string>
>mapValues : <T, TResult>(obj: Dictionary<T> | NumericDictionary<T>, callback: ObjectIterator<Dictionary<T>, TResult>) => Dictionary<TResult>
>mapValues : <T, TResult>(obj: Dictionary<T> | NumericDictionary<T>, callback: DictionaryIterator<T, TResult>) => Dictionary<TResult>
>foos : Record<string, Foo>
>f => f.foo : (f: Foo) => string
>f : Foo
Expand Down
12 changes: 6 additions & 6 deletions tests/baselines/reference/genericIsNeverEmptyObject.types
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Expand Up @@ -2,18 +2,18 @@
// Repro from #29067

function test<T extends { a: string }>(obj: T) {
>test : <T extends { a: string; }>(obj: T) => Pick<T, Exclude<keyof T, "a">> & { b: string; }
>test : <T extends { a: string; }>(obj: T) => Omit<T, "a"> & { b: string; }
>a : string
>obj : T

let { a, ...rest } = obj;
>a : string
>rest : Pick<T, Exclude<keyof T, "a">>
>rest : Omit<T, "a">
>obj : T

return { ...rest, b: a };
>{ ...rest, b: a } : Pick<T, Exclude<keyof T, "a">> & { b: string; }
>rest : Pick<T, Exclude<keyof T, "a">>
>{ ...rest, b: a } : Omit<T, "a"> & { b: string; }
>rest : Omit<T, "a">
>b : string
>a : string
}
Expand All @@ -30,7 +30,7 @@ let o2: { b: string, x: number } = test(o1);
>o2 : { b: string; x: number; }
>b : string
>x : number
>test(o1) : Pick<{ a: string; x: number; }, "x"> & { b: string; }
>test : <T extends { a: string; }>(obj: T) => Pick<T, Exclude<keyof T, "a">> & { b: string; }
>test(o1) : Omit<{ a: string; x: number; }, "a"> & { b: string; }
>test : <T extends { a: string; }>(obj: T) => Omit<T, "a"> & { b: string; }
>o1 : { a: string; x: number; }

16 changes: 8 additions & 8 deletions tests/baselines/reference/genericObjectRest.types
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Expand Up @@ -16,32 +16,32 @@ function f1<T extends { a: string, b: number }>(obj: T) {
let { a: a1, ...r1 } = obj;
>a : any
>a1 : string
>r1 : Pick<T, Exclude<keyof T, "a">>
>r1 : Omit<T, "a">
>obj : T

let { a: a2, b: b2, ...r2 } = obj;
>a : any
>a2 : string
>b : any
>b2 : number
>r2 : Pick<T, Exclude<keyof T, "a" | "b">>
>r2 : Omit<T, "a" | "b">
>obj : T

let { 'a': a3, ...r3 } = obj;
>a3 : string
>r3 : Pick<T, Exclude<keyof T, "a">>
>r3 : Omit<T, "a">
>obj : T

let { ['a']: a4, ...r4 } = obj;
>'a' : "a"
>a4 : string
>r4 : Pick<T, Exclude<keyof T, "a">>
>r4 : Omit<T, "a">
>obj : T

let { [a]: a5, ...r5 } = obj;
>a : "a"
>a5 : string
>r5 : Pick<T, Exclude<keyof T, "a">>
>r5 : Omit<T, "a">
>obj : T
}

Expand All @@ -68,7 +68,7 @@ function f2<T extends { [sa]: string, [sb]: number }>(obj: T) {
>a1 : string
>sb : unique symbol
>b1 : number
>r1 : Pick<T, Exclude<keyof T, unique symbol | unique symbol>>
>r1 : Omit<T, unique symbol | unique symbol>
>obj : T
}

Expand All @@ -83,7 +83,7 @@ function f3<T, K1 extends keyof T, K2 extends keyof T>(obj: T, k1: K1, k2: K2) {
>a1 : T[K1]
>k2 : K2
>a2 : T[K2]
>r1 : Pick<T, Exclude<keyof T, K1 | K2>>
>r1 : Omit<T, K1 | K2>
>obj : T
}

Expand All @@ -104,7 +104,7 @@ function f4<K1 extends keyof Item, K2 extends keyof Item>(obj: Item, k1: K1, k2:
>a1 : Item[K1]
>k2 : K2
>a2 : Item[K2]
>r1 : Pick<Item, Exclude<"a", K1 | K2> | Exclude<"b", K1 | K2> | Exclude<"c", K1 | K2>>
>r1 : Omit<Item, K1 | K2>
>obj : Item
}

8 changes: 4 additions & 4 deletions tests/baselines/reference/infiniteConstraints.errors.txt
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@@ -1,6 +1,6 @@
tests/cases/compiler/infiniteConstraints.ts(4,37): error TS2536: Type '"val"' cannot be used to index type 'B[Exclude<keyof B, K>]'.
tests/cases/compiler/infiniteConstraints.ts(31,43): error TS2322: Type 'Record<"val", "dup">' is not assignable to type 'never'.
tests/cases/compiler/infiniteConstraints.ts(31,63): error TS2322: Type 'Record<"val", "dup">' is not assignable to type 'never'.
tests/cases/compiler/infiniteConstraints.ts(31,43): error TS2322: Type 'Value<"dup">' is not assignable to type 'never'.
tests/cases/compiler/infiniteConstraints.ts(31,63): error TS2322: Type 'Value<"dup">' is not assignable to type 'never'.
tests/cases/compiler/infiniteConstraints.ts(36,71): error TS2536: Type '"foo"' cannot be used to index type 'T[keyof T]'.


Expand Down Expand Up @@ -39,10 +39,10 @@ tests/cases/compiler/infiniteConstraints.ts(36,71): error TS2536: Type '"foo"' c

const shouldBeError = ensureNoDuplicates({main: value("dup"), alternate: value("dup")});
~~~~
!!! error TS2322: Type 'Record<"val", "dup">' is not assignable to type 'never'.
!!! error TS2322: Type 'Value<"dup">' is not assignable to type 'never'.
!!! related TS6500 tests/cases/compiler/infiniteConstraints.ts:31:43: The expected type comes from property 'main' which is declared here on type '{ main: never; alternate: never; }'
~~~~~~~~~
!!! error TS2322: Type 'Record<"val", "dup">' is not assignable to type 'never'.
!!! error TS2322: Type 'Value<"dup">' is not assignable to type 'never'.
!!! related TS6500 tests/cases/compiler/infiniteConstraints.ts:31:63: The expected type comes from property 'alternate' which is declared here on type '{ main: never; alternate: never; }'

// Repro from #26448
Expand Down
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