Can I use TypeScript overloads when using fat arrow syntax for class methods?

Question

I've converted some classes from the conventional form:

class TestOverloads {     private status = "blah";     public doStuff(selector: JQuery);     public doStuff(selector: string);     public doStuff(selector: any) {         alert(this.status);     } } 

to use arrow function expressions instead:

class TestOverloads2 {     private status = "blah";     public doStuff = (selector: any) => {         alert(this.status);     } } 

so as to avoid scoping problems when the class methods are used in a callback (see here for background).

I can't work out how to recreate my overloaded function signatures though. How would I write my overloads when using the fat arrow?

Answer 1

You can write an inline type literal for the call signatures the function supports:

class TestOverloads2 {     private status = "blah";     public doStuff: {         (selector: JQuery): void;         (selector: string): void;     } = (selector: any) => {         alert(this.status);     } } 

That's sort of hideous, so you might want to extract it into an interface instead:

interface SelectByJQueryOrString {     (selector: JQuery): void;     (selector: string): void; }  class TestOverloads3 {     private status = "blah";     public doStuff: SelectByJQueryOrString = (selector: any) => {         alert(this.status);     } }