TypeScript 动态参数和返回类型
我正在开发一个 Angular 应用程序,该应用程序必须与一个具有某些安全限制的后端进行通信,这些限制我在每次调用时都必须处理。为了方便处理这些调用,我创建了一个像这样的封装方法:
type ApiResponse<T = any> = {
status: number,
data: T,
error?: string
}
type ApiCall<T=any> = (...args: any[]) => ApiResponse<T>;
const makeApiCall = <T extends ApiCall>(apiCall: T, ...params: Parameters<T>): ReturnType<T> => {
// Execute the "apiCall" method with the parameters, deal with restrictions, parse the response etc
}
所以,假设我有两个 API 调用(它们可以有任意数量的参数和类型):
const f1: ApiCall<string> = (a: number, b: string) => {
// Do logic
return {
status: 200,
data: "Data sample"
}
}
const f2: ApiCall<string[]> = (a: string, b: string, c: number, d: number) => {
// Do logic
return {
status: 200,
data: [ a, b ]
}
}
我可以使用封装器来运行它们:
makeApiCall(f1, 2, 4);
makeApiCall(f2, "String", "Another", 10, 20);
然而,没有什么能阻止我发送错误的参数数量或类型,例如:
makeApiCall(f1, 2, 4, "WRONG PARAMETER");
makeApiCall(f2, "Wrong number and type of params", 10, true);
是否有可能在上述定义中实现类型安全,以便 Typescript 编译器在使用包装器时显示提示和错误?
提前谢谢,
答案#1
尽量避免声明显式的泛型参数。TS 应该推断所有类型。让它来做繁重的工作 :)
type ApiResponse<T> = {
status: number,
data: T,
error?: string
}
type Fn = (...args: any[]) => any
const makeApiCall = <
F extends Fn
>(apiCall: F, ...params: Parameters<F>): ReturnType<F> =>
apiCall(...params)
const f1 = (a: number, b: string) => {
// Do logic
return {
status: 200,
data: [a, b]
}
}
const f2 = (a: string, b: string, c: number, d: number) => {
// Do logic
return {
status: 200,
data: [a, b]
}
}
/**
* Ok
*/
// Return -> { status: number; data: (string|number)[]; }
const result1 = makeApiCall(f1, 42, 'str');
// Return -> { status: number; data: string[]; }
const result2 = makeApiCall(f2, "String", "Another", 10, 20);
/**
* Errors
*/
makeApiCall(f1, 2, 4); // expected error
makeApiCall(f1, 2, 4, "WRONG PARAMETER"); // expected error
makeApiCall(f2, "Wrong number and type of params", 10, true); // expected error
操场
