@types/koa-compose

compose: {
    <T1, U1, T2, U2>(
        middleware: [Koa.Middleware<T1, U1>, Koa.Middleware<T2, U2>]
    ): Koa.Middleware<T1 & T2, U1 & U2>;
    <T1, U1, T2, U2, T3, U3>(
        middleware: [
            Koa.Middleware<T1, U1>,
            Koa.Middleware<T2, U2>,
            Koa.Middleware<T3, U3>
        ]
    ): Koa.Middleware<T1 & T2 & T3, U1 & U2 & U3>;
    <T1, U1, T2, U2, T3, U3, T4, U4>(
        middleware: [
            Koa.Middleware<T1, U1>,
            Koa.Middleware<T2, U2>,
            Koa.Middleware<T3, U3>,
            Koa.Middleware<T4, U4>
        ]
    ): Koa.Middleware<T1 & T2 & T3 & T4, U1 & U2 & U3 & U4>;
    <T1, U1, T2, U2, T3, U3, T4, U4, T5, U5>(
        middleware: [
            Koa.Middleware<T1, U1>,
            Koa.Middleware<T2, U2>,
            Koa.Middleware<T3, U3>,
            Koa.Middleware<T4, U4>,
            Koa.Middleware<T5, U5>
        ]
    ): Koa.Middleware<T1 & T2 & T3 & T4 & T5, U1 & U2 & U3 & U4 & U5>;
    <T1, U1, T2, U2, T3, U3, T4, U4, T5, U5, T6, U6>(
        middleware: [
            Koa.Middleware<T1, U1>,
            Koa.Middleware<T2, U2>,
            Koa.Middleware<T3, U3>,
            Koa.Middleware<T4, U4>,
            Koa.Middleware<T5, U5>,
            Koa.Middleware<T6, U6>
        ]
    ): Koa.Middleware<T1 & T2 & T3 & T4 & T5 & T6, U1 & U2 & U3 & U4 & U5 & U6>;
    <T1, U1, T2, U2, T3, U3, T4, U4, T5, U5, T6, U6, T7, U7>(
        middleware: [
            Koa.Middleware<T1, U1>,
            Koa.Middleware<T2, U2>,
            Koa.Middleware<T3, U3>,
            Koa.Middleware<T4, U4>,
            Koa.Middleware<T5, U5>,
            Koa.Middleware<T6, U6>,
            Koa.Middleware<T7, U7>
        ]
    ): Koa.Middleware<
        T1 & T2 & T3 & T4 & T5 & T6 & T7,
        U1 & U2 & U3 & U4 & U5 & U6 & U7
    >;
    <T1, U1, T2, U2, T3, U3, T4, U4, T5, U5, T6, U6, T7, U7, T8, U8>(
        middleware: [
            Koa.Middleware<T1, U1>,
            Koa.Middleware<T2, U2>,
            Koa.Middleware<T3, U3>,
            Koa.Middleware<T4, U4>,
            Koa.Middleware<T5, U5>,
            Koa.Middleware<T6, U6>,
            Koa.Middleware<T7, U7>,
            Koa.Middleware<T8, U8>
        ]
    ): Koa.Middleware<
        T1 & T2 & T3 & T4 & T5 & T6 & T7 & T8,
        U1 & U2 & U3 & U4 & U5 & U6 & U7 & U8
    >;
    <T>(middleware: compose.Middleware<T>[]): compose.ComposedMiddleware<T>;
};

type ComposedMiddleware<T> = (context: T, next?: Koa.Next) => Promise<void>;

type Middleware<T> = (context: T, next: Koa.Next) => any;