swc/crates/swc_ecma_parser/tests/tsc/duplicateStringIndexers.ts

// it is an error to have duplicate index signatures of the same kind in a type

module test {
    interface Number {
        [x: string]: string;
        [x: string]: string;
    }

    interface String {
        [x: string]: string;
        [x: string]: string;
    }

    interface Array<T> {
        [x: string]: T;
        [x: string]: T;
    }

    class C {
        [x: string]: string;
        [x: string]: string;
    }

    interface I {
        [x: string]: string;
        [x: string]: string;
    }

    var a: {
        [x: string]: string;
        [x: string]: string;
    }
}