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//// [unionTypeMembers.ts]
interface I1<T> {
commonMethodType(a: string): string;
commonPropertyType: string;
commonMethodDifferentParameterType(a: string): string;
commonMethodDifferentReturnType(a: string): string;
commonPropertyDifferenType: string;
commonMethodWithTypeParameter(a: T): T;
commonMethodWithOwnTypeParameter<U>(a: U): U;
methodOnlyInI1(a: string): string;
propertyOnlyInI1: string;
}
interface I2<T> {
commonMethodType(a: string): string;
commonPropertyType: string;
commonMethodDifferentParameterType(a: number): number;
commonMethodDifferentReturnType(a: string): number;
commonPropertyDifferenType: number;
commonMethodWithTypeParameter(a: T): T;
commonMethodWithOwnTypeParameter<U>(a: U): U;
methodOnlyInI2(a: string): string;
propertyOnlyInI2: string;
}
// a union type U has those members that are present in every one of its constituent types,
// with types that are unions of the respective members in the constituent types
var x : I1<number> | I2<number>;
var str: string;
var num: number;
var strOrNum: string | number;
// If each type in U has a property P, U has a property P of a union type of the types of P from each type in U.
str = x.commonPropertyType; // string
str = x.commonMethodType(str); // (a: string) => string so result should be string
strOrNum = x.commonPropertyDifferenType;
strOrNum = x.commonMethodDifferentReturnType(str); // string | union
x.commonMethodDifferentParameterType; // No error - property exists
x.commonMethodDifferentParameterType(strOrNum); // error - no call signatures because the type of this property is ((a: string) => string) | (a: number) => number
// and the call signatures arent identical
num = x.commonMethodWithTypeParameter(num);
num = x.commonMethodWithOwnTypeParameter(num);
str = x.commonMethodWithOwnTypeParameter(str);
strOrNum = x.commonMethodWithOwnTypeParameter(strOrNum);
x.propertyOnlyInI1; // error
x.propertyOnlyInI2; // error
x.methodOnlyInI1("hello"); // error
x.methodOnlyInI2(10); // error
//// [unionTypeMembers.js]
// a union type U has those members that are present in every one of its constituent types,
// with types that are unions of the respective members in the constituent types
var x;
var str;
var num;
var strOrNum;
// If each type in U has a property P, U has a property P of a union type of the types of P from each type in U.
str = x.commonPropertyType; // string
str = x.commonMethodType(str); // (a: string) => string so result should be string
strOrNum = x.commonPropertyDifferenType;
strOrNum = x.commonMethodDifferentReturnType(str); // string | union
x.commonMethodDifferentParameterType; // No error - property exists
x.commonMethodDifferentParameterType(strOrNum); // error - no call signatures because the type of this property is ((a: string) => string) | (a: number) => number
// and the call signatures arent identical
num = x.commonMethodWithTypeParameter(num);
num = x.commonMethodWithOwnTypeParameter(num);
str = x.commonMethodWithOwnTypeParameter(str);
strOrNum = x.commonMethodWithOwnTypeParameter(strOrNum);
x.propertyOnlyInI1; // error
x.propertyOnlyInI2; // error
x.methodOnlyInI1("hello"); // error
x.methodOnlyInI2(10); // error
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