从http://stackoverflow.com/questions/41336330/typescript-how-can-i-make-an-existing-namespace-global找到

export {};

declare global {
    namespace foo {
        export var a;
    }
    import bar = foo;
}

我相信这不应该产生错误，但是它返回了错误

Imports are not permitted in module augmentations. Consider moving them to the enclosing external module.