Support specific api features

[ccadete]

Since some browsers api are specific to the browser support, an annotation could validate the availability of the method in respect to the runtime. For example, a JSObject method/field annotated with:

public @interface Chrome {
    public String version() default "";
}

or a generic:

public @interface Browser {
    public String name() default ""; 
    public String version() default "";
}

could be validated by a processor, that check if the method/field is available. The runtime would be given as parameter in the maven plugin.
This avoid runtime errors, and manual check from the developer.

[konsoletyper]

This is a useful feature. However, is should be introduced very carefully, as there is usecase when a user wants browser-specific API when available, i.e.:

if (!JS.isUndefined(document.getMozFullScreen())) {
    // do something
}

Might it be annotation to suppress errors in such cases?

I would split version into integer parts, as it is unclear how to compare strings in general and make name enumerated instead of string. Additionaly, there should be annotation named Browsers to indicate, that a method is available in several browsers.

[ccadete]

Could it be validated at compile time with a visitor that traverses the byte code and check if the annotated methods can be used?

[konsoletyper]

TeaVM could do in in the simpliest cases, but in general it could produce lots of positive errors. It's a general problem of static analyzers.