swc/crates/swc_ecma_parser/tests/tsc/assignmentCompatWithCallSignaturesWithOptionalParameters.ts

69 lines
2.3 KiB
TypeScript

// call signatures in derived types must have the same or fewer optional parameters as the base type
interface Base {
a: () => number;
a2: (x?: number) => number;
a3: (x: number) => number;
a4: (x: number, y?: number) => number;
a5: (x?: number, y?: number) => number;
a6: (x: number, y: number) => number;
}
var b: Base;
var a: () => number;
a = () => 1 // ok, same number of required params
a = (x?: number) => 1; // ok, same number of required params
a = (x: number) => 1; // error, too many required params
a = b.a; // ok
a = b.a2; // ok
a = b.a3; // error
a = b.a4; // error
a = b.a5; // ok
a = b.a6; // error
var a2: (x?: number) => number;
a2 = () => 1; // ok, same number of required params
a2 = (x?: number) => 1; // ok, same number of required params
a2 = (x: number) => 1; // ok, same number of params
a2 = b.a; // ok
a2 = b.a2; // ok
a2 = b.a3; // ok, same number of params
a2 = b.a4; // ok, excess params are optional in b.a3
a2 = b.a5; // ok
a2 = b.a6; // error
var a3: (x: number) => number;
a3 = () => 1; // ok, fewer required params
a3 = (x?: number) => 1; // ok, fewer required params
a3 = (x: number) => 1; // ok, same number of required params
a3 = (x: number, y: number) => 1; // error, too many required params
a3 = b.a; // ok
a3 = b.a2; // ok
a3 = b.a3; // ok
a3 = b.a4; // ok
a3 = b.a5; // ok
a3 = b.a6; // error
var a4: (x: number, y?: number) => number;
a4 = () => 1; // ok, fewer required params
a4 = (x?: number, y?: number) => 1; // ok, fewer required params
a4 = (x: number) => 1; // ok, same number of required params
a4 = (x: number, y: number) => 1; // ok, same number of params
a4 = b.a; // ok
a4 = b.a2; // ok
a4 = b.a3; // ok
a4 = b.a4; // ok
a4 = b.a5; // ok
a4 = b.a6; // ok, same number of params
var a5: (x?: number, y?: number) => number;
a5 = () => 1; // ok, fewer required params
a5 = (x?: number, y?: number) => 1; // ok, fewer required params
a5 = (x: number) => 1; // ok, fewer params in lambda
a5 = (x: number, y: number) => 1; // ok, same number of params
a5 = b.a; // ok
a5 = b.a2; // ok
a5 = b.a3; // ok, fewer params in b.a3
a5 = b.a4; // ok, same number of params
a5 = b.a5; // ok
a5 = b.a6; // ok, same number of params