Closure Compiler issues warning with namespaced enum

问题

The following sample code generates a compiler warning on advanced optimization: "JSC_UNSAFE_NAMESPACE: incomplete alias created for namespace NS". If I remove the @enum comment, it doesn't give the warning.

var NS = {};

/**
 * @enum {string}
 */
NS.type = {
    FOO : 'bar'
};

NS.foobar = function(){ alert(NS.type.FOO); };

window['NS'] = NS;
window['NS']['foobar'] = NS.foobar;

Exporting only the function and not the namespace also seems to work:

window['NS_foobar'] = NS.foobar;

What am I doing wrong? Is there a way around this? I'd rather not include the Closure library if possible.

回答1:

The compiler expects to collapse the enum value into single variables:

NS.type.FOO becomes NS$type$FOO. The "NS" that you exported would not contain what you expect.

I suspect you want something like this:

window['NS'] = {}; // an external namespace object.
window['NS']['foobar'] = NS.foobar; // add 'foobar' to the external namespace.

来源：https://stackoverflow.com/questions/8178382/closure-compiler-issues-warning-with-namespaced-enum