Nested class in TypeScript throwing error

Question

I was following instructions in the official TypeScript handbook under the section "Merging Namespaces with Classes" for how to get nested classes. But it looks like if I try to add a function declaration of any type in the child class definition I get the TS error

"An accessor cannot be declared in an ambient context"

I don't know what this means or why I'm getting this when I'm following the example exactly as far as I can tell.

export class Schedule {
    // ...
}

export declare namespace Schedule {
    export class MaxGracePeriod {
        // Static, read-only constants in TypeScript (See: https://stackoverflow.com/a/22993349/1504964)
        public static get Hourly(): number { return 12; }
        public static get Daily(): number { return 12; }
        public static get Weekly(): number { return 12; }
        public static get Monthly(): number { return 24; }
        public static get Yearly(): number { return 24; }       
        //                ~~~~~~ => "An accessor cannot be declared in an ambient context"
    }

    export enum DaysOfWeek {
        Sunday = 0,
        Monday = 1,
        Tuesday = 2,
        Wednesday = 3,
        Thursday = 4,
        Friday = 5,
        Saturday = 6,
    }
}

I get the red squiggle and error on the Hourly(), Daily(), etc. definitions.

Hint: if you never use the constructor of your class, and it does not have any methods besides static ones, you should not be using class syntax at all. — Bergi
– Bergi, Commented Feb 5, 2018 at 17:17
A simple object literal. For typing? Yes, probably an interface. — Bergi
– Bergi, Commented Feb 5, 2018 at 18:42
@Bergi Hmm it gives me a bunch of errors with my method declarations if I change it to interface... — Kyle V.
– Kyle V., Commented Feb 5, 2018 at 18:53

Suren Srapyan · Accepted Answer · 2018-02-05 17:09:10Z

1

Remove declare from the namespace definition. You don't need that.

export class Schedule {
    // ...
}

export namespace Schedule {
    export class MaxGracePeriod {
        public static get Hourly(): number { return 12; }
        public static get Daily(): number { return 12; }
        public static get Weekly(): number { return 12; }
        public static get Monthly(): number { return 24; }
        public static get Yearly(): number { return 24; }       
    }

    export enum DaysOfWeek {
        Sunday = 0,
        Monday = 1,
        Tuesday = 2,
        Wednesday = 3,
        Thursday = 4,
        Friday = 5,
        Saturday = 6,
    }
}

answered Feb 5, 2018 at 17:09

Suren Srapyan

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