定义我想作为输入的 function 类型：Typescript

Question

I want to make sure that my input accepts only below function as an argument:

  async getAll<T extends Entity>(url: string, params?: any): Promise<T[]> {
     // func body
  }

My function :

  setFunc(getAllFunc: any){
    this.func = getAllFunc;
  }

I want to replace any with custom type.

Thanks in advance.

Answer 1

You can either use an interface or a type for this.

Type:

type TGetAllFunc<T extends Entity> = (url: string, params? : any) => Promise<T[]>;

Interface:

interface IGetAllFunc<T extends Entity> {
    (url: string, params? : any): Promise<T[]>;
}

Then you can pass in either one to the function(I passed in the Interface here):

setFunc(getAllFunc: IGetAllFunc<Entity>){
  this.func = getAllFunc;
}

Answer 2

Based on your function the type of your getAll function is as follows:

type FunctionType<T> = (string, any) => Promise<T[]>;

You can then rewrite your function setFunc to take in the function type.

setFunc(getAllFunc: FunctionType<T>){
    this.func = getAllFunc;
}

It seems like you set getAllFunc to class property, so that means that you would need to have your class also generic. so your class would look something like this,

type FunctionType<T> = (string, any) => Promise<T[]>;

class SomeClass<T> { // named SomeClass for brevity, use your own name here
    func: FunctionType<T>

    setFunc(getAllFunc: FunctionType<T>){
        this.func = getAllFunc;
    }

    /* ... */
}