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Merge pull request #23672 from Microsoft/intersectionWithUnionConstraint

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Type relationships for intersections with union constraints
This commit is contained in:
Anders Hejlsberg 2018-04-27 15:53:00 -07:00 committed by GitHub
commit 6c28da328e
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16 changed files with 506 additions and 28 deletions
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75
src/compiler/checker.ts
View file

@ -6470,6 +6470,47 @@ namespace ts {
return getConstraintOfDistributiveConditionalType(type) || getDefaultConstraintOfConditionalType(type);
}
function getUnionConstraintOfIntersection(type: IntersectionType, targetIsUnion: boolean) {
let constraints: Type[];
let hasDisjointDomainType = false;
for (const t of type.types) {
if (t.flags & TypeFlags.Instantiable) {
// We keep following constraints as long as we have an instantiable type that is known
// not to be circular or infinite (hence we stop on index access types).
let constraint = getConstraintOfType(t);
while (constraint && constraint.flags & (TypeFlags.TypeParameter | TypeFlags.Index | TypeFlags.Conditional)) {
constraint = getConstraintOfType(constraint);
}
if (constraint) {
// A constraint that isn't a union type implies that the final type would be a non-union
// type as well. Since non-union constraints are of no interest, we can exit here.
if (!(constraint.flags & TypeFlags.Union)) {
return undefined;
}
constraints = append(constraints, constraint);
}
}
else if (t.flags & TypeFlags.DisjointDomains) {
hasDisjointDomainType = true;
}
}
// If the target is a union type or if we are intersecting with types belonging to one of the
// disjoint domans, we may end up producing a constraint that hasn't been examined before.
if (constraints && (targetIsUnion || hasDisjointDomainType)) {
if (hasDisjointDomainType) {
// We add any types belong to one of the disjoint domans because they might cause the final
// intersection operation to reduce the union constraints.
for (const t of type.types) {
if (t.flags & TypeFlags.DisjointDomains) {
constraints = append(constraints, t);
}
}
}
return getIntersectionType(constraints);
}
return undefined;
}
function getBaseConstraintOfInstantiableNonPrimitiveUnionOrIntersection(type: Type) {
if (type.flags & (TypeFlags.InstantiableNonPrimitive | TypeFlags.UnionOrIntersection)) {
const constraint = getResolvedBaseConstraint(<InstantiableType | UnionOrIntersectionType>type);
@ -7951,8 +7992,14 @@ namespace ts {
return binarySearch(types, type, getTypeId, compareValues) >= 0;
}
// Return true if the given intersection type contains (a) more than one unit type or (b) an object
// type and a nullable type (null or undefined).
// Return true if the given intersection type contains
// more than one unit type or,
// an object type and a nullable type (null or undefined), or
// a string-like type and a type known to be non-string-like, or
// a number-like type and a type known to be non-number-like, or
// a symbol-like type and a type known to be non-symbol-like, or
// a void-like type and a type known to be non-void-like, or
// a non-primitive type and a type known to be primitive.
function isEmptyIntersectionType(type: IntersectionType) {
let combined: TypeFlags = 0;
for (const t of type.types) {
@ -7960,7 +8007,12 @@ namespace ts {
return true;
}
combined |= t.flags;
if (combined & TypeFlags.Nullable && combined & (TypeFlags.Object | TypeFlags.NonPrimitive)) {
if (combined & TypeFlags.Nullable && combined & (TypeFlags.Object | TypeFlags.NonPrimitive) ||
combined & TypeFlags.NonPrimitive && combined & (TypeFlags.DisjointDomains & ~TypeFlags.NonPrimitive) ||
combined & TypeFlags.StringLike && combined & (TypeFlags.DisjointDomains & ~TypeFlags.StringLike) ||
combined & TypeFlags.NumberLike && combined & (TypeFlags.DisjointDomains & ~TypeFlags.NumberLike) ||
combined & TypeFlags.ESSymbolLike && combined & (TypeFlags.DisjointDomains & ~TypeFlags.ESSymbolLike) ||
combined & TypeFlags.VoidLike && combined & (TypeFlags.DisjointDomains & ~TypeFlags.VoidLike)) {
return true;
}
}
@ -10180,6 +10232,23 @@ namespace ts {
}
}
}
if (!result && source.flags & TypeFlags.Intersection) {
// The combined constraint of an intersection type is the intersection of the constraints of
// the constituents. When an intersection type contains instantiable types with union type
// constraints, there are situations where we need to examine the combined constraint. One is
// when the target is a union type. Another is when the intersection contains types belonging
// to one of the disjoint domains. For example, given type variables T and U, each with the
// constraint 'string | number', the combined constraint of 'T & U' is 'string | number' and
// we need to check this constraint against a union on the target side. Also, given a type
// variable V constrained to 'string | number', 'V & number' has a combined constraint of
// 'string & number | number & number' which reduces to just 'number'.
const constraint = getUnionConstraintOfIntersection(<IntersectionType>source, !!(target.flags & TypeFlags.Union));
if (constraint) {
if (result = isRelatedTo(constraint, target, reportErrors)) {
errorInfo = saveErrorInfo;
}
}
}
isIntersectionConstituent = saveIsIntersectionConstituent;

3
src/compiler/types.ts
View file

@ -3620,6 +3620,9 @@ namespace ts {
BooleanLike = Boolean | BooleanLiteral,
EnumLike = Enum | EnumLiteral,
ESSymbolLike = ESSymbol | UniqueESSymbol,
VoidLike = Void | Undefined,
/* @internal */
DisjointDomains = NonPrimitive | StringLike | NumberLike | BooleanLike | ESSymbolLike | VoidLike | Null,
UnionOrIntersection = Union | Intersection,
StructuredType = Object | Union | Intersection,
TypeVariable = TypeParameter | IndexedAccess,

1
tests/baselines/reference/api/tsserverlibrary.d.ts vendored
View file

@ -2111,6 +2111,7 @@ declare namespace ts {
BooleanLike = 136,
EnumLike = 272,
ESSymbolLike = 1536,
VoidLike = 6144,
UnionOrIntersection = 393216,
StructuredType = 458752,
TypeVariable = 1081344,

1
tests/baselines/reference/api/typescript.d.ts vendored
View file

@ -2111,6 +2111,7 @@ declare namespace ts {
BooleanLike = 136,
EnumLike = 272,
ESSymbolLike = 1536,
VoidLike = 6144,
UnionOrIntersection = 393216,
StructuredType = 458752,
TypeVariable = 1081344,

7
tests/baselines/reference/errorMessagesIntersectionTypes04.errors.txt
View file

@ -1,11 +1,9 @@
tests/cases/compiler/errorMessagesIntersectionTypes04.ts(17,5): error TS2322: Type 'A & B' is not assignable to type 'number'.
tests/cases/compiler/errorMessagesIntersectionTypes04.ts(18,5): error TS2322: Type 'A & B' is not assignable to type 'boolean'.
tests/cases/compiler/errorMessagesIntersectionTypes04.ts(19,5): error TS2322: Type 'A & B' is not assignable to type 'string'.
tests/cases/compiler/errorMessagesIntersectionTypes04.ts(21,5): error TS2322: Type '(number & true) | (number & false)' is not assignable to type 'string'.
Type 'number & true' is not assignable to type 'string'.
==== tests/cases/compiler/errorMessagesIntersectionTypes04.ts (4 errors) ====
==== tests/cases/compiler/errorMessagesIntersectionTypes04.ts (3 errors) ====
interface A {
a;
}
@ -33,7 +31,4 @@ tests/cases/compiler/errorMessagesIntersectionTypes04.ts(21,5): error TS2322: Ty
!!! error TS2322: Type 'A & B' is not assignable to type 'string'.
str = num_and_bool;
~~~
!!! error TS2322: Type '(number & true) | (number & false)' is not assignable to type 'string'.
!!! error TS2322: Type 'number & true' is not assignable to type 'string'.
}

6
tests/baselines/reference/errorMessagesIntersectionTypes04.types
View file

@ -36,7 +36,7 @@ function f<T, U extends A, V extends U>(): void {
>B : B
let num_and_bool: number & boolean;
>num_and_bool : (number & true) | (number & false)
>num_and_bool : never
num = a_and_b;
>num = a_and_b : A & B
@ -54,7 +54,7 @@ function f<T, U extends A, V extends U>(): void {
>a_and_b : A & B
str = num_and_bool;
>str = num_and_bool : (number & true) | (number & false)
>str = num_and_bool : never
>str : string
>num_and_bool : (number & true) | (number & false)
>num_and_bool : never
}

83
tests/baselines/reference/intersectionWithUnionConstraint.errors.txt Normal file
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@ -0,0 +1,83 @@
tests/cases/conformance/types/intersection/intersectionWithUnionConstraint.ts(7,9): error TS2322: Type 'T & U' is not assignable to type 'string | number'.
Type 'string | undefined' is not assignable to type 'string | number'.
Type 'undefined' is not assignable to type 'string | number'.
Type 'T & U' is not assignable to type 'number'.
tests/cases/conformance/types/intersection/intersectionWithUnionConstraint.ts(8,9): error TS2322: Type 'T & U' is not assignable to type 'string | null'.
Type 'string | undefined' is not assignable to type 'string | null'.
Type 'undefined' is not assignable to type 'string | null'.
Type 'T & U' is not assignable to type 'string'.
tests/cases/conformance/types/intersection/intersectionWithUnionConstraint.ts(10,9): error TS2322: Type 'T & U' is not assignable to type 'number | null'.
Type 'string | undefined' is not assignable to type 'number | null'.
Type 'undefined' is not assignable to type 'number | null'.
Type 'T & U' is not assignable to type 'number'.
tests/cases/conformance/types/intersection/intersectionWithUnionConstraint.ts(11,9): error TS2322: Type 'T & U' is not assignable to type 'number | undefined'.
Type 'string | undefined' is not assignable to type 'number | undefined'.
Type 'string' is not assignable to type 'number | undefined'.
Type 'T & U' is not assignable to type 'number'.
tests/cases/conformance/types/intersection/intersectionWithUnionConstraint.ts(12,9): error TS2322: Type 'T & U' is not assignable to type 'null | undefined'.
Type 'string | undefined' is not assignable to type 'null | undefined'.
Type 'string' is not assignable to type 'null | undefined'.
Type 'T & U' is not assignable to type 'null'.
==== tests/cases/conformance/types/intersection/intersectionWithUnionConstraint.ts (5 errors) ====
function f1<T extends string | number, U extends string | number>(x: T & U) {
// Combined constraint of 'T & U' is 'string | number'
let y: string | number = x;
}
function f2<T extends string | number | undefined, U extends string | null | undefined>(x: T & U) {
let y1: string | number = x; // Error
~~
!!! error TS2322: Type 'T & U' is not assignable to type 'string | number'.
!!! error TS2322: Type 'string | undefined' is not assignable to type 'string | number'.
!!! error TS2322: Type 'undefined' is not assignable to type 'string | number'.
!!! error TS2322: Type 'T & U' is not assignable to type 'number'.
let y2: string | null = x; // Error
~~
!!! error TS2322: Type 'T & U' is not assignable to type 'string | null'.
!!! error TS2322: Type 'string | undefined' is not assignable to type 'string | null'.
!!! error TS2322: Type 'undefined' is not assignable to type 'string | null'.
!!! error TS2322: Type 'T & U' is not assignable to type 'string'.
let y3: string | undefined = x;
let y4: number | null = x; // Error
~~
!!! error TS2322: Type 'T & U' is not assignable to type 'number | null'.
!!! error TS2322: Type 'string | undefined' is not assignable to type 'number | null'.
!!! error TS2322: Type 'undefined' is not assignable to type 'number | null'.
!!! error TS2322: Type 'T & U' is not assignable to type 'number'.
let y5: number | undefined = x; // Error
~~
!!! error TS2322: Type 'T & U' is not assignable to type 'number | undefined'.
!!! error TS2322: Type 'string | undefined' is not assignable to type 'number | undefined'.
!!! error TS2322: Type 'string' is not assignable to type 'number | undefined'.
!!! error TS2322: Type 'T & U' is not assignable to type 'number'.
let y6: null | undefined = x; // Error
~~
!!! error TS2322: Type 'T & U' is not assignable to type 'null | undefined'.
!!! error TS2322: Type 'string | undefined' is not assignable to type 'null | undefined'.
!!! error TS2322: Type 'string' is not assignable to type 'null | undefined'.
!!! error TS2322: Type 'T & U' is not assignable to type 'null'.
}
type T1 = (string | number | undefined) & (string | null | undefined); // string | undefined
function f3<T extends string | number | undefined>(x: T & (number | object | undefined)) {
const y: number | undefined = x;
}
function f4<T extends string | number>(x: T & (number | object)) {
const y: number = x;
}
function f5<T, U extends keyof T>(x: keyof T & U) {
let y: keyof any = x;
}
// Repro from #23648
type Example<T, U> = { [K in keyof T]: K extends keyof U ? UnexpectedError<K> : NoErrorHere<K> }
type UnexpectedError<T extends PropertyKey> = T
type NoErrorHere<T extends PropertyKey> = T

60
tests/baselines/reference/intersectionWithUnionConstraint.js Normal file
View file

@ -0,0 +1,60 @@
//// [intersectionWithUnionConstraint.ts]
function f1<T extends string | number, U extends string | number>(x: T & U) {
// Combined constraint of 'T & U' is 'string | number'
let y: string | number = x;
}
function f2<T extends string | number | undefined, U extends string | null | undefined>(x: T & U) {
let y1: string | number = x; // Error
let y2: string | null = x; // Error
let y3: string | undefined = x;
let y4: number | null = x; // Error
let y5: number | undefined = x; // Error
let y6: null | undefined = x; // Error
}
type T1 = (string | number | undefined) & (string | null | undefined); // string | undefined
function f3<T extends string | number | undefined>(x: T & (number | object | undefined)) {
const y: number | undefined = x;
}
function f4<T extends string | number>(x: T & (number | object)) {
const y: number = x;
}
function f5<T, U extends keyof T>(x: keyof T & U) {
let y: keyof any = x;
}
// Repro from #23648
type Example<T, U> = { [K in keyof T]: K extends keyof U ? UnexpectedError<K> : NoErrorHere<K> }
type UnexpectedError<T extends PropertyKey> = T
type NoErrorHere<T extends PropertyKey> = T
//// [intersectionWithUnionConstraint.js]
"use strict";
function f1(x) {
// Combined constraint of 'T & U' is 'string | number'
var y = x;
}
function f2(x) {
var y1 = x; // Error
var y2 = x; // Error
var y3 = x;
var y4 = x; // Error
var y5 = x; // Error
var y6 = x; // Error
}
function f3(x) {
var y = x;
}
function f4(x) {
var y = x;
}
function f5(x) {
var y = x;
}

114
tests/baselines/reference/intersectionWithUnionConstraint.symbols Normal file
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@ -0,0 +1,114 @@
=== tests/cases/conformance/types/intersection/intersectionWithUnionConstraint.ts ===
function f1<T extends string | number, U extends string | number>(x: T & U) {
>f1 : Symbol(f1, Decl(intersectionWithUnionConstraint.ts, 0, 0))
>T : Symbol(T, Decl(intersectionWithUnionConstraint.ts, 0, 12))
>U : Symbol(U, Decl(intersectionWithUnionConstraint.ts, 0, 38))
>x : Symbol(x, Decl(intersectionWithUnionConstraint.ts, 0, 66))
>T : Symbol(T, Decl(intersectionWithUnionConstraint.ts, 0, 12))
>U : Symbol(U, Decl(intersectionWithUnionConstraint.ts, 0, 38))
// Combined constraint of 'T & U' is 'string | number'
let y: string | number = x;
>y : Symbol(y, Decl(intersectionWithUnionConstraint.ts, 2, 7))
>x : Symbol(x, Decl(intersectionWithUnionConstraint.ts, 0, 66))
}
function f2<T extends string | number | undefined, U extends string | null | undefined>(x: T & U) {
>f2 : Symbol(f2, Decl(intersectionWithUnionConstraint.ts, 3, 1))
>T : Symbol(T, Decl(intersectionWithUnionConstraint.ts, 5, 12))
>U : Symbol(U, Decl(intersectionWithUnionConstraint.ts, 5, 50))
>x : Symbol(x, Decl(intersectionWithUnionConstraint.ts, 5, 88))
>T : Symbol(T, Decl(intersectionWithUnionConstraint.ts, 5, 12))
>U : Symbol(U, Decl(intersectionWithUnionConstraint.ts, 5, 50))
let y1: string | number = x; // Error
>y1 : Symbol(y1, Decl(intersectionWithUnionConstraint.ts, 6, 7))
>x : Symbol(x, Decl(intersectionWithUnionConstraint.ts, 5, 88))
let y2: string | null = x; // Error
>y2 : Symbol(y2, Decl(intersectionWithUnionConstraint.ts, 7, 7))
>x : Symbol(x, Decl(intersectionWithUnionConstraint.ts, 5, 88))
let y3: string | undefined = x;
>y3 : Symbol(y3, Decl(intersectionWithUnionConstraint.ts, 8, 7))
>x : Symbol(x, Decl(intersectionWithUnionConstraint.ts, 5, 88))
let y4: number | null = x; // Error
>y4 : Symbol(y4, Decl(intersectionWithUnionConstraint.ts, 9, 7))
>x : Symbol(x, Decl(intersectionWithUnionConstraint.ts, 5, 88))
let y5: number | undefined = x; // Error
>y5 : Symbol(y5, Decl(intersectionWithUnionConstraint.ts, 10, 7))
>x : Symbol(x, Decl(intersectionWithUnionConstraint.ts, 5, 88))
let y6: null | undefined = x; // Error
>y6 : Symbol(y6, Decl(intersectionWithUnionConstraint.ts, 11, 7))
>x : Symbol(x, Decl(intersectionWithUnionConstraint.ts, 5, 88))
}
type T1 = (string | number | undefined) & (string | null | undefined); // string | undefined
>T1 : Symbol(T1, Decl(intersectionWithUnionConstraint.ts, 12, 1))
function f3<T extends string | number | undefined>(x: T & (number | object | undefined)) {
>f3 : Symbol(f3, Decl(intersectionWithUnionConstraint.ts, 14, 70))
>T : Symbol(T, Decl(intersectionWithUnionConstraint.ts, 16, 12))
>x : Symbol(x, Decl(intersectionWithUnionConstraint.ts, 16, 51))
>T : Symbol(T, Decl(intersectionWithUnionConstraint.ts, 16, 12))
const y: number | undefined = x;
>y : Symbol(y, Decl(intersectionWithUnionConstraint.ts, 17, 9))
>x : Symbol(x, Decl(intersectionWithUnionConstraint.ts, 16, 51))
}
function f4<T extends string | number>(x: T & (number | object)) {
>f4 : Symbol(f4, Decl(intersectionWithUnionConstraint.ts, 18, 1))
>T : Symbol(T, Decl(intersectionWithUnionConstraint.ts, 20, 12))
>x : Symbol(x, Decl(intersectionWithUnionConstraint.ts, 20, 39))
>T : Symbol(T, Decl(intersectionWithUnionConstraint.ts, 20, 12))
const y: number = x;
>y : Symbol(y, Decl(intersectionWithUnionConstraint.ts, 21, 9))
>x : Symbol(x, Decl(intersectionWithUnionConstraint.ts, 20, 39))
}
function f5<T, U extends keyof T>(x: keyof T & U) {
>f5 : Symbol(f5, Decl(intersectionWithUnionConstraint.ts, 22, 1))
>T : Symbol(T, Decl(intersectionWithUnionConstraint.ts, 24, 12))
>U : Symbol(U, Decl(intersectionWithUnionConstraint.ts, 24, 14))
>T : Symbol(T, Decl(intersectionWithUnionConstraint.ts, 24, 12))
>x : Symbol(x, Decl(intersectionWithUnionConstraint.ts, 24, 34))
>T : Symbol(T, Decl(intersectionWithUnionConstraint.ts, 24, 12))
>U : Symbol(U, Decl(intersectionWithUnionConstraint.ts, 24, 14))
let y: keyof any = x;
>y : Symbol(y, Decl(intersectionWithUnionConstraint.ts, 25, 7))
>x : Symbol(x, Decl(intersectionWithUnionConstraint.ts, 24, 34))
}
// Repro from #23648
type Example<T, U> = { [K in keyof T]: K extends keyof U ? UnexpectedError<K> : NoErrorHere<K> }
>Example : Symbol(Example, Decl(intersectionWithUnionConstraint.ts, 26, 1))
>T : Symbol(T, Decl(intersectionWithUnionConstraint.ts, 30, 13))
>U : Symbol(U, Decl(intersectionWithUnionConstraint.ts, 30, 15))
>K : Symbol(K, Decl(intersectionWithUnionConstraint.ts, 30, 24))
>T : Symbol(T, Decl(intersectionWithUnionConstraint.ts, 30, 13))
>K : Symbol(K, Decl(intersectionWithUnionConstraint.ts, 30, 24))
>U : Symbol(U, Decl(intersectionWithUnionConstraint.ts, 30, 15))
>UnexpectedError : Symbol(UnexpectedError, Decl(intersectionWithUnionConstraint.ts, 30, 96))
>K : Symbol(K, Decl(intersectionWithUnionConstraint.ts, 30, 24))
>NoErrorHere : Symbol(NoErrorHere, Decl(intersectionWithUnionConstraint.ts, 32, 47))
>K : Symbol(K, Decl(intersectionWithUnionConstraint.ts, 30, 24))
type UnexpectedError<T extends PropertyKey> = T
>UnexpectedError : Symbol(UnexpectedError, Decl(intersectionWithUnionConstraint.ts, 30, 96))
>T : Symbol(T, Decl(intersectionWithUnionConstraint.ts, 32, 21))
>PropertyKey : Symbol(PropertyKey, Decl(lib.d.ts, --, --))
>T : Symbol(T, Decl(intersectionWithUnionConstraint.ts, 32, 21))
type NoErrorHere<T extends PropertyKey> = T
>NoErrorHere : Symbol(NoErrorHere, Decl(intersectionWithUnionConstraint.ts, 32, 47))
>T : Symbol(T, Decl(intersectionWithUnionConstraint.ts, 33, 17))
>PropertyKey : Symbol(PropertyKey, Decl(lib.d.ts, --, --))
>T : Symbol(T, Decl(intersectionWithUnionConstraint.ts, 33, 17))

119
tests/baselines/reference/intersectionWithUnionConstraint.types Normal file
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@ -0,0 +1,119 @@
=== tests/cases/conformance/types/intersection/intersectionWithUnionConstraint.ts ===
function f1<T extends string | number, U extends string | number>(x: T & U) {
>f1 : <T extends string | number, U extends string | number>(x: T & U) => void
>T : T
>U : U
>x : T & U
>T : T
>U : U
// Combined constraint of 'T & U' is 'string | number'
let y: string | number = x;
>y : string | number
>x : T & U
}
function f2<T extends string | number | undefined, U extends string | null | undefined>(x: T & U) {
>f2 : <T extends string | number | undefined, U extends string | null | undefined>(x: T & U) => void
>T : T
>U : U
>null : null
>x : T & U
>T : T
>U : U
let y1: string | number = x; // Error
>y1 : string | number
>x : T & U
let y2: string | null = x; // Error
>y2 : string | null
>null : null
>x : T & U
let y3: string | undefined = x;
>y3 : string | undefined
>x : T & U
let y4: number | null = x; // Error
>y4 : number | null
>null : null
>x : T & U
let y5: number | undefined = x; // Error
>y5 : number | undefined
>x : T & U
let y6: null | undefined = x; // Error
>y6 : null | undefined
>null : null
>x : T & U
}
type T1 = (string | number | undefined) & (string | null | undefined); // string | undefined
>T1 : string | undefined
>null : null
function f3<T extends string | number | undefined>(x: T & (number | object | undefined)) {
>f3 : <T extends string | number | undefined>(x: (T & undefined) | (T & number) | (T & object)) => void
>T : T
>x : (T & undefined) | (T & number) | (T & object)
>T : T
const y: number | undefined = x;
>y : number | undefined
>x : (T & undefined) | (T & number) | (T & object)
}
function f4<T extends string | number>(x: T & (number | object)) {
>f4 : <T extends string | number>(x: (T & number) | (T & object)) => void
>T : T
>x : (T & number) | (T & object)
>T : T
const y: number = x;
>y : number
>x : (T & number) | (T & object)
}
function f5<T, U extends keyof T>(x: keyof T & U) {
>f5 : <T, U extends keyof T>(x: keyof T & U) => void
>T : T
>U : U
>T : T
>x : keyof T & U
>T : T
>U : U
let y: keyof any = x;
>y : string | number | symbol
>x : keyof T & U
}
// Repro from #23648
type Example<T, U> = { [K in keyof T]: K extends keyof U ? UnexpectedError<K> : NoErrorHere<K> }
>Example : Example<T, U>
>T : T
>U : U
>K : K
>T : T
>K : K
>U : U
>UnexpectedError : T
>K : K
>NoErrorHere : T
>K : K
type UnexpectedError<T extends PropertyKey> = T
>UnexpectedError : T
>T : T
>PropertyKey : string | number | symbol
>T : T
type NoErrorHere<T extends PropertyKey> = T
>NoErrorHere : T
>T : T
>PropertyKey : string | number | symbol
>T : T

4
tests/baselines/reference/keyofAndIndexedAccessErrors.errors.txt
View file

@ -44,6 +44,7 @@ tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(87,5): error
tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(103,9): error TS2322: Type 'Extract<keyof T, string>' is not assignable to type 'K'.
Type 'string & keyof T' is not assignable to type 'K'.
Type 'string' is not assignable to type 'K'.
Type 'string' is not assignable to type 'K'.
tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(105,9): error TS2322: Type 'T[Extract<keyof T, string>]' is not assignable to type 'T[K]'.
Type 'Extract<keyof T, string>' is not assignable to type 'K'.
tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(108,5): error TS2322: Type 'T[K]' is not assignable to type 'U[K]'.
@ -55,6 +56,7 @@ tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(114,5): error
Type 'Extract<keyof T, string>' is not assignable to type 'J'.
Type 'string & keyof T' is not assignable to type 'J'.
Type 'string' is not assignable to type 'J'.
Type 'string' is not assignable to type 'J'.
tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(117,5): error TS2322: Type 'T[K]' is not assignable to type 'U[J]'.
Type 'T' is not assignable to type 'U'.
@ -238,6 +240,7 @@ tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(117,5): error
!!! error TS2322: Type 'Extract<keyof T, string>' is not assignable to type 'K'.
!!! error TS2322: Type 'string & keyof T' is not assignable to type 'K'.
!!! error TS2322: Type 'string' is not assignable to type 'K'.
!!! error TS2322: Type 'string' is not assignable to type 'K'.
t[key] = tk; // ok, T[K] ==> T[keyof T]
tk = t[key]; // error, T[keyof T] =/=> T[K]
~~
@ -264,6 +267,7 @@ tests/cases/conformance/types/keyof/keyofAndIndexedAccessErrors.ts(117,5): error
!!! error TS2322: Type 'Extract<keyof T, string>' is not assignable to type 'J'.
!!! error TS2322: Type 'string & keyof T' is not assignable to type 'J'.
!!! error TS2322: Type 'string' is not assignable to type 'J'.
!!! error TS2322: Type 'string' is not assignable to type 'J'.
tk = uj;
uj = tk; // error

8
tests/baselines/reference/keyofAndIndexedAccessErrors.types
View file

@ -34,19 +34,19 @@ type T02 = keyof keyof Object;
>Object : Object
type T03 = keyof keyof keyof Object;
>T03 : "toString" | "valueOf" | ("toString" & number) | ("toLocaleString" & number) | ("valueOf" & number) | ("toFixed" & number) | ("toExponential" & number) | ("toPrecision" & number)
>T03 : "toString" | "valueOf"
>Object : Object
type T04 = keyof keyof keyof keyof Object;
>T04 : number | "length" | "toString" | "valueOf" | "charAt" | "charCodeAt" | "concat" | "indexOf" | "lastIndexOf" | "localeCompare" | "match" | "replace" | "search" | "slice" | "split" | "substring" | "toLowerCase" | "toLocaleLowerCase" | "toUpperCase" | "toLocaleUpperCase" | "trim" | "substr" | ("toString" & number) | ("valueOf" & number) | (number & "length") | (number & "toString") | (number & "toLocaleString") | (number & "valueOf") | (number & "charAt") | (number & "charCodeAt") | (number & "concat") | (number & "indexOf") | (number & "lastIndexOf") | (number & "localeCompare") | (number & "match") | (number & "replace") | (number & "search") | (number & "slice") | (number & "split") | (number & "substring") | (number & "toLowerCase") | (number & "toLocaleLowerCase") | (number & "toUpperCase") | (number & "toLocaleUpperCase") | (number & "trim") | (number & "substr") | (number & "toFixed") | (number & "toExponential") | (number & "toPrecision") | ("length" & number) | ("charAt" & number) | ("charCodeAt" & number) | ("concat" & number) | ("indexOf" & number) | ("lastIndexOf" & number) | ("localeCompare" & number) | ("match" & number) | ("replace" & number) | ("search" & number) | ("slice" & number) | ("split" & number) | ("substring" & number) | ("toLowerCase" & number) | ("toLocaleLowerCase" & number) | ("toUpperCase" & number) | ("toLocaleUpperCase" & number) | ("trim" & number) | ("substr" & number)
>T04 : number | "length" | "toString" | "valueOf" | "charAt" | "charCodeAt" | "concat" | "indexOf" | "lastIndexOf" | "localeCompare" | "match" | "replace" | "search" | "slice" | "split" | "substring" | "toLowerCase" | "toLocaleLowerCase" | "toUpperCase" | "toLocaleUpperCase" | "trim" | "substr"
>Object : Object
type T05 = keyof keyof keyof keyof keyof Object;
>T05 : "toString" | "valueOf" | ("toString" & number) | ("toLocaleString" & number) | ("valueOf" & number) | ("toFixed" & number) | ("toExponential" & number) | ("toPrecision" & number)
>T05 : "toString" | "valueOf"
>Object : Object
type T06 = keyof keyof keyof keyof keyof keyof Object;
>T06 : number | "length" | "toString" | "valueOf" | "charAt" | "charCodeAt" | "concat" | "indexOf" | "lastIndexOf" | "localeCompare" | "match" | "replace" | "search" | "slice" | "split" | "substring" | "toLowerCase" | "toLocaleLowerCase" | "toUpperCase" | "toLocaleUpperCase" | "trim" | "substr" | ("toString" & number) | ("valueOf" & number) | (number & "length") | (number & "toString") | (number & "toLocaleString") | (number & "valueOf") | (number & "charAt") | (number & "charCodeAt") | (number & "concat") | (number & "indexOf") | (number & "lastIndexOf") | (number & "localeCompare") | (number & "match") | (number & "replace") | (number & "search") | (number & "slice") | (number & "split") | (number & "substring") | (number & "toLowerCase") | (number & "toLocaleLowerCase") | (number & "toUpperCase") | (number & "toLocaleUpperCase") | (number & "trim") | (number & "substr") | (number & "toFixed") | (number & "toExponential") | (number & "toPrecision") | ("length" & number) | ("charAt" & number) | ("charCodeAt" & number) | ("concat" & number) | ("indexOf" & number) | ("lastIndexOf" & number) | ("localeCompare" & number) | ("match" & number) | ("replace" & number) | ("search" & number) | ("slice" & number) | ("split" & number) | ("substring" & number) | ("toLowerCase" & number) | ("toLocaleLowerCase" & number) | ("toUpperCase" & number) | ("toLocaleUpperCase" & number) | ("trim" & number) | ("substr" & number)
>T06 : number | "length" | "toString" | "valueOf" | "charAt" | "charCodeAt" | "concat" | "indexOf" | "lastIndexOf" | "localeCompare" | "match" | "replace" | "search" | "slice" | "split" | "substring" | "toLowerCase" | "toLocaleLowerCase" | "toUpperCase" | "toLocaleUpperCase" | "trim" | "substr"
>Object : Object
type T10 = Shape["name"];

9
tests/baselines/reference/switchCaseWithIntersectionTypes01.errors.txt
View file

@ -1,10 +1,7 @@
tests/cases/conformance/types/typeRelationships/comparable/switchCaseWithIntersectionTypes01.ts(18,10): error TS2678: Type '(number & true) | (number & false)' is not comparable to type 'string & number'.
Type 'number & false' is not comparable to type 'string & number'.
Type 'number & false' is not comparable to type 'string'.
tests/cases/conformance/types/typeRelationships/comparable/switchCaseWithIntersectionTypes01.ts(22,10): error TS2678: Type 'boolean' is not comparable to type 'string & number'.
==== tests/cases/conformance/types/typeRelationships/comparable/switchCaseWithIntersectionTypes01.ts (2 errors) ====
==== tests/cases/conformance/types/typeRelationships/comparable/switchCaseWithIntersectionTypes01.ts (1 errors) ====
var strAndNum: string & number;
var numAndBool: number & boolean;
var str: string;
@ -23,10 +20,6 @@ tests/cases/conformance/types/typeRelationships/comparable/switchCaseWithInterse
// Overlap in constituents
case numAndBool:
~~~~~~~~~~
!!! error TS2678: Type '(number & true) | (number & false)' is not comparable to type 'string & number'.
!!! error TS2678: Type 'number & false' is not comparable to type 'string & number'.
!!! error TS2678: Type 'number & false' is not comparable to type 'string'.
break;
// No relation

4
tests/baselines/reference/switchCaseWithIntersectionTypes01.types
View file

@ -3,7 +3,7 @@ var strAndNum: string & number;
>strAndNum : string & number
var numAndBool: number & boolean;
>numAndBool : (number & true) | (number & false)
>numAndBool : never
var str: string;
>str : string
@ -34,7 +34,7 @@ switch (strAndNum) {
// Overlap in constituents
case numAndBool:
>numAndBool : (number & true) | (number & false)
>numAndBool : never
break;

4
tests/baselines/reference/typeGuardsWithInstanceOf.types
View file

@ -25,7 +25,7 @@ if (!(result instanceof RegExp)) {
} else if (!result.global) {
>!result.global : boolean
>result.global : (string & true) | (string & false)
>result.global : never
>result : I & RegExp
>global : (string & true) | (string & false)
>global : never
}

36
tests/cases/conformance/types/intersection/intersectionWithUnionConstraint.ts Normal file
View file

@ -0,0 +1,36 @@
// @strict: true
function f1<T extends string | number, U extends string | number>(x: T & U) {
// Combined constraint of 'T & U' is 'string | number'
let y: string | number = x;
}
function f2<T extends string | number | undefined, U extends string | null | undefined>(x: T & U) {
let y1: string | number = x; // Error
let y2: string | null = x; // Error
let y3: string | undefined = x;
let y4: number | null = x; // Error
let y5: number | undefined = x; // Error
let y6: null | undefined = x; // Error
}
type T1 = (string | number | undefined) & (string | null | undefined); // string | undefined
function f3<T extends string | number | undefined>(x: T & (number | object | undefined)) {
const y: number | undefined = x;
}
function f4<T extends string | number>(x: T & (number | object)) {
const y: number = x;
}
function f5<T, U extends keyof T>(x: keyof T & U) {
let y: keyof any = x;
}
// Repro from #23648
type Example<T, U> = { [K in keyof T]: K extends keyof U ? UnexpectedError<K> : NoErrorHere<K> }
type UnexpectedError<T extends PropertyKey> = T
type NoErrorHere<T extends PropertyKey> = T