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tests/cases/conformance/interfaces/interfaceDeclarations/interfaceWithMultipleBaseTypes.ts(21,11): error TS2430: Interface 'Derived2' incorrectly extends interface 'Base2'.
Types of property 'x' are incompatible.
Type '{ a: string; b: number; }' is not assignable to type '{ b: string; }'.
Types of property 'b' are incompatible.
Type 'number' is not assignable to type 'string'.
tests/cases/conformance/interfaces/interfaceDeclarations/interfaceWithMultipleBaseTypes.ts(52,15): error TS2320: Interface 'Derived3<T>' cannot simultaneously extend types 'Base1<number>' and 'Base2<number>'.
Named property 'x' of types 'Base1<number>' and 'Base2<number>' are not identical.
tests/cases/conformance/interfaces/interfaceDeclarations/interfaceWithMultipleBaseTypes.ts(54,15): error TS2430: Interface 'Derived4<T>' incorrectly extends interface 'Base1<number>'.
Types of property 'x' are incompatible.
Type '{ a: T; b: T; }' is not assignable to type '{ a: number; }'.
Types of property 'a' are incompatible.
Type 'T' is not assignable to type 'number'.
tests/cases/conformance/interfaces/interfaceDeclarations/interfaceWithMultipleBaseTypes.ts(54,15): error TS2430: Interface 'Derived4<T>' incorrectly extends interface 'Base2<number>'.
Types of property 'x' are incompatible.
Type '{ a: T; b: T; }' is not assignable to type '{ b: number; }'.
Types of property 'b' are incompatible.
Type 'T' is not assignable to type 'number'.
tests/cases/conformance/interfaces/interfaceDeclarations/interfaceWithMultipleBaseTypes.ts(60,15): error TS2430: Interface 'Derived5<T>' incorrectly extends interface 'Base1<T>'.
Types of property 'x' are incompatible.
Type 'T' is not assignable to type '{ a: T; }'.
tests/cases/conformance/interfaces/interfaceDeclarations/interfaceWithMultipleBaseTypes.ts(60,15): error TS2430: Interface 'Derived5<T>' incorrectly extends interface 'Base2<T>'.
Types of property 'x' are incompatible.
Type 'T' is not assignable to type '{ b: T; }'.
==== tests/cases/conformance/interfaces/interfaceDeclarations/interfaceWithMultipleBaseTypes.ts (6 errors) ====
// an interface may have multiple bases with properties of the same name as long as the interface's implementation satisfies all base type versions
interface Base1 {
x: {
a: string;
}
}
interface Base2 {
x: {
b: string;
}
}
interface Derived extends Base1, Base2 {
x: {
a: string; b: string;
}
}
interface Derived2 extends Base1, Base2 { // error
~~~~~~~~
!!! error TS2430: Interface 'Derived2' incorrectly extends interface 'Base2'.
!!! error TS2430: Types of property 'x' are incompatible.
!!! error TS2430: Type '{ a: string; b: number; }' is not assignable to type '{ b: string; }'.
!!! error TS2430: Types of property 'b' are incompatible.
!!! error TS2430: Type 'number' is not assignable to type 'string'.
x: {
a: string; b: number;
}
}
module Generic {
interface Base1<T> {
x: {
a: T;
}
}
interface Base2<T> {
x: {
b: T;
}
}
interface Derived<T> extends Base1<string>, Base2<number> {
x: {
a: string; b: number;
}
}
interface Derived2<T, U> extends Base1<T>, Base2<U> {
x: {
a: T; b: U;
}
}
interface Derived3<T> extends Base1<number>, Base2<number> { } // error
~~~~~~~~
!!! error TS2320: Interface 'Derived3<T>' cannot simultaneously extend types 'Base1<number>' and 'Base2<number>'.
!!! error TS2320: Named property 'x' of types 'Base1<number>' and 'Base2<number>' are not identical.
interface Derived4<T> extends Base1<number>, Base2<number> { // error
~~~~~~~~
!!! error TS2430: Interface 'Derived4<T>' incorrectly extends interface 'Base1<number>'.
!!! error TS2430: Types of property 'x' are incompatible.
!!! error TS2430: Type '{ a: T; b: T; }' is not assignable to type '{ a: number; }'.
!!! error TS2430: Types of property 'a' are incompatible.
!!! error TS2430: Type 'T' is not assignable to type 'number'.
~~~~~~~~
!!! error TS2430: Interface 'Derived4<T>' incorrectly extends interface 'Base2<number>'.
!!! error TS2430: Types of property 'x' are incompatible.
!!! error TS2430: Type '{ a: T; b: T; }' is not assignable to type '{ b: number; }'.
!!! error TS2430: Types of property 'b' are incompatible.
!!! error TS2430: Type 'T' is not assignable to type 'number'.
x: {
a: T; b: T;
}
}
interface Derived5<T> extends Base1<T>, Base2<T> { // error
~~~~~~~~
!!! error TS2430: Interface 'Derived5<T>' incorrectly extends interface 'Base1<T>'.
!!! error TS2430: Types of property 'x' are incompatible.
!!! error TS2430: Type 'T' is not assignable to type '{ a: T; }'.
~~~~~~~~
!!! error TS2430: Interface 'Derived5<T>' incorrectly extends interface 'Base2<T>'.
!!! error TS2430: Types of property 'x' are incompatible.
!!! error TS2430: Type 'T' is not assignable to type '{ b: T; }'.
x: T;
}
}
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