Typescript Duplicate Function Implementation
I have defined the following two function signatures in the same Typescript class, i.e.,
public emit<T1>(event: string, arg1: T1): void {}
and
public emit<T1,T2>(event: string, arg1: T1, arg2: T2): void {}
However when transpiling the typescript I get the following error
error TS2393: Duplicate function implementation.
I thought you could overload functions in typescript providing the number of parameters in the function signature were different. Given that the above signatures have 2 and 3 parameters respectively, why am I getting this transpilation error?
I'm assuming your code looks like this:
public emit<T1>(event: string, arg1: T1): void {}
public emit<T1,T2>(event: string, arg1: T1, arg2: T2): void {}
public emit(event: string, ...args: any[]): void {
// actual implementation here
}
The problem is that you have {}
after the first 2 lines. This actually defines an empty implementation of a function, i.e. something like:
function empty() {}
You only want to define a type for the function, not an implementation. So replace the empty blocks with just a semi-colon:
public emit<T1>(event: string, arg1: T1): void;
public emit<T1,T2>(event: string, arg1: T1, arg2: T2): void;
public emit(event: string, ...args: any[]): void {
// actual implementation here
}
export {}
Just add this line at the top of the typescript file