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Properly distribute over unions in keyof for mapped types with as clause (#40837)

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* Properly distribute over unions in keyof mapped types with as clause

* Accept new baselines

* Add regression test

* Accept new baselines
This commit is contained in:
Anders Hejlsberg
2020-10-01 09:36:51 -07:00
committed by GitHub
parent 35111231f7
commit 4538e7352f
5 changed files with 126 additions and 3 deletions
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src/compiler/checker.ts
+3 -2
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@@ -13436,8 +13436,9 @@ namespace ts {
function getIndexTypeForMappedType(type: MappedType, noIndexSignatures: boolean | undefined) {
const constraint = filterType(getConstraintTypeFromMappedType(type), t => !(noIndexSignatures && t.flags & (TypeFlags.Any | TypeFlags.String)));
return type.declaration.nameType ?
instantiateType(getTypeFromTypeNode(type.declaration.nameType), appendTypeMapping(type.mapper, getTypeParameterFromMappedType(type), constraint)) :
const nameType = type.declaration.nameType && getTypeFromTypeNode(type.declaration.nameType);
return nameType ?
mapType(constraint, t => instantiateType(nameType, appendTypeMapping(type.mapper, getTypeParameterFromMappedType(type), t))) :
constraint;
}
tests/baselines/reference/mappedTypeAsClauses.js
+30
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@@ -42,11 +42,30 @@ interface Person {
}
type LazyPerson = Lazyify<Person>;
// Repro from #40833
type Example = {foo: string, bar: number};
type PickByValueType<T, U> = {
[K in keyof T as T[K] extends U ? K : never]: T[K]
};
type T1 = PickByValueType<Example, string>;
const e1: T1 = {
foo: "hello"
};
type T2 = keyof T1;
const e2: T2 = "foo";
//// [mappedTypeAsClauses.js]
"use strict";
// Mapped type 'as N' clauses
var e1 = {
foo: "hello"
};
var e2 = "foo";
//// [mappedTypeAsClauses.d.ts]
@@ -105,3 +124,14 @@ interface Person {
location?: string;
}
declare type LazyPerson = Lazyify<Person>;
declare type Example = {
foo: string;
bar: number;
};
declare type PickByValueType<T, U> = {
[K in keyof T as T[K] extends U ? K : never]: T[K];
};
declare type T1 = PickByValueType<Example, string>;
declare const e1: T1;
declare type T2 = keyof T1;
declare const e2: T2;
tests/baselines/reference/mappedTypeAsClauses.symbols
+45
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@@ -143,3 +143,48 @@ type LazyPerson = Lazyify<Person>;
>Lazyify : Symbol(Lazyify, Decl(mappedTypeAsClauses.ts, 28, 34))
>Person : Symbol(Person, Decl(mappedTypeAsClauses.ts, 34, 2))
// Repro from #40833
type Example = {foo: string, bar: number};
>Example : Symbol(Example, Decl(mappedTypeAsClauses.ts, 42, 34))
>foo : Symbol(foo, Decl(mappedTypeAsClauses.ts, 46, 16))
>bar : Symbol(bar, Decl(mappedTypeAsClauses.ts, 46, 28))
type PickByValueType<T, U> = {
>PickByValueType : Symbol(PickByValueType, Decl(mappedTypeAsClauses.ts, 46, 42))
>T : Symbol(T, Decl(mappedTypeAsClauses.ts, 48, 21))
>U : Symbol(U, Decl(mappedTypeAsClauses.ts, 48, 23))
[K in keyof T as T[K] extends U ? K : never]: T[K]
>K : Symbol(K, Decl(mappedTypeAsClauses.ts, 49, 3))
>T : Symbol(T, Decl(mappedTypeAsClauses.ts, 48, 21))
>T : Symbol(T, Decl(mappedTypeAsClauses.ts, 48, 21))
>K : Symbol(K, Decl(mappedTypeAsClauses.ts, 49, 3))
>U : Symbol(U, Decl(mappedTypeAsClauses.ts, 48, 23))
>K : Symbol(K, Decl(mappedTypeAsClauses.ts, 49, 3))
>T : Symbol(T, Decl(mappedTypeAsClauses.ts, 48, 21))
>K : Symbol(K, Decl(mappedTypeAsClauses.ts, 49, 3))
};
type T1 = PickByValueType<Example, string>;
>T1 : Symbol(T1, Decl(mappedTypeAsClauses.ts, 50, 2))
>PickByValueType : Symbol(PickByValueType, Decl(mappedTypeAsClauses.ts, 46, 42))
>Example : Symbol(Example, Decl(mappedTypeAsClauses.ts, 42, 34))
const e1: T1 = {
>e1 : Symbol(e1, Decl(mappedTypeAsClauses.ts, 53, 5))
>T1 : Symbol(T1, Decl(mappedTypeAsClauses.ts, 50, 2))
foo: "hello"
>foo : Symbol(foo, Decl(mappedTypeAsClauses.ts, 53, 16))
};
type T2 = keyof T1;
>T2 : Symbol(T2, Decl(mappedTypeAsClauses.ts, 55, 2))
>T1 : Symbol(T1, Decl(mappedTypeAsClauses.ts, 50, 2))
const e2: T2 = "foo";
>e2 : Symbol(e2, Decl(mappedTypeAsClauses.ts, 57, 5))
>T2 : Symbol(T2, Decl(mappedTypeAsClauses.ts, 55, 2))
tests/baselines/reference/mappedTypeAsClauses.types
+33 -1
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@@ -61,7 +61,7 @@ type TD1 = DoubleProp<{ a: string, b: number }>; // { a1: string, a2: string, b
>b : number
type TD2 = keyof TD1; // 'a1' | 'a2' | 'b1' | 'b2'
>TD2 : "a1" | "b1" | "a2" | "b2"
>TD2 : "a1" | "a2" | "b1" | "b2"
type TD3<U> = keyof DoubleProp<U>; // `${keyof U & string}1` | `${keyof U & string}2`
>TD3 : `${keyof U & string}1` | `${keyof U & string}2`
@@ -88,3 +88,35 @@ interface Person {
type LazyPerson = Lazyify<Person>;
>LazyPerson : Lazyify<Person>
// Repro from #40833
type Example = {foo: string, bar: number};
>Example : Example
>foo : string
>bar : number
type PickByValueType<T, U> = {
>PickByValueType : PickByValueType<T, U>
[K in keyof T as T[K] extends U ? K : never]: T[K]
};
type T1 = PickByValueType<Example, string>;
>T1 : PickByValueType<Example, string>
const e1: T1 = {
>e1 : PickByValueType<Example, string>
>{ foo: "hello"} : { foo: string; }
foo: "hello"
>foo : string
>"hello" : "hello"
};
type T2 = keyof T1;
>T2 : "foo"
const e2: T2 = "foo";
>e2 : "foo"
>"foo" : "foo"
tests/cases/conformance/types/mapped/mappedTypeAsClauses.ts
+15
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@@ -44,3 +44,18 @@ interface Person {
}
type LazyPerson = Lazyify<Person>;
// Repro from #40833
type Example = {foo: string, bar: number};
type PickByValueType<T, U> = {
[K in keyof T as T[K] extends U ? K : never]: T[K]
};
type T1 = PickByValueType<Example, string>;
const e1: T1 = {
foo: "hello"
};
type T2 = keyof T1;
const e2: T2 = "foo";