//// [subtypingWithCallSignaturesWithRestParameters.ts] // call signatures in derived types must have the same or fewer optional parameters as the base type interface Base { a: (...args: number[]) => number; a2: (x: number, ...z: number[]) => number; a3: (x: number, y?: string, ...z: number[]) => number; a4: (x?: number, y?: string, ...z: number[]) => number; } interface I1 extends Base { a: () => number; // ok, same number of required params } interface I1B extends Base { a: (...args: number[]) => number; // ok, same number of required params } interface I1C extends Base { a: (...args: string[]) => number; // error, type mismatch } interface I2 extends Base { a: (x?: number) => number; // ok, same number of required params } interface I2B extends Base { a: (x?: number, y?: number, z?: number) => number; // ok, same number of required params } interface I3 extends Base { a: (x: number) => number; // ok, all present params match } interface I3B extends Base { a: (x?: string) => number; // error, incompatible type } interface I4 extends Base { a2: () => number; // ok, fewer required params } interface I4B extends Base { a2: (...args: number[]) => number; // ok, fewer required params } interface I5 extends Base { a2: (x?: number) => number; // ok, fewer required params } interface I6 extends Base { a2: (x: number) => number; // ok, same number of required params } interface I6B extends Base { a2: (x: number, ...args: number[]) => number; // ok, same number of required params } interface I6C extends Base { a2: (x: number, ...args: string[]) => number; // error } interface I6D extends Base { a2: (x: number, y: number) => number; // ok, all present params match } interface I6E extends Base { a2: (x: number, y?: number) => number; // ok, same number of required params } interface I7 extends Base { a3: () => number; // ok, fewer required params } interface I8 extends Base { a3: (x?: number) => number; // ok, fewer required params } interface I9 extends Base { a3: (x: number) => number; // ok, same number of required params } interface I10 extends Base { a3: (x: number, y: string) => number; // ok, all present params match } interface I10B extends Base { a3: (x: number, y?: number, z?: number) => number; // error } interface I10C extends Base { a3: (x: number, ...z: number[]) => number; // error } interface I10D extends Base { a3: (x: string, y?: string, z?: string) => number; // error, incompatible types } interface I10E extends Base { a3: (x: number, ...z: string[]) => number; // error } interface I11 extends Base { a4: () => number; // ok, fewer required params } interface I12 extends Base { a4: (x?: number, y?: number) => number; // error, type mismatch } interface I13 extends Base { a4: (x: number) => number; // ok, all present params match } interface I14 extends Base { a4: (x: number, y?: number) => number; // error, second param has type mismatch } interface I15 extends Base { a4: (x?: number, y?: string) => number; // ok, same number of required params with matching types } interface I16 extends Base { a4: (x: number, ...args: string[]) => number; // error, rest param has type mismatch } interface I17 extends Base { a4: (...args: number[]) => number; // error } //// [subtypingWithCallSignaturesWithRestParameters.js]