NoMethodError calling callMethod on instance of reopened Java class

I looked through the JRuby code and found that receiver must be an instance of IRubyObject. Neither the method signature nor the method documentation hints at this.

Using JavaEmbedUtils I changed the example to this:

import org.jruby.embed.ScriptingContainer;
import org.jruby.javasupport.JavaEmbedUtils;

class JRUBY_6785 {
    public JRUBY_6785() {}

    public static void main(String[] args) throws Exception {
        ScriptingContainer sc = new ScriptingContainer();
        sc.put("JRUBY_6785", sc.runScriptlet("Java::JRUBY_6785"));
        sc.runScriptlet("class JRUBY_6785 ; def ruby_method ; puts 'Success!' ; end ; end");
        sc.callMethod(JavaEmbedUtils.javaToRuby(sc.getProvider().getRuntime(), new JRUBY_6785()), "ruby_method");
    }
}

This seems to work. Woohoo!

Is this the right/best way to do it?

Attached a patch that changes ScriptingContainer#callMethod() to automatically call JavaEmbedUtils.javaToRuby() on the receiver if it is not an IRubyObject.

Also treat null/nil as a regular receiver for consistency.

All tests are green after the patch.

This patch makes the original example work.

Here is an even simpler patch that removes the duplicated tests for IRubyObject.

The original example still works, and all tests are green.

Patch may be ok...will defer to Yoko for review.

Yoko and I have discussed the change, and she has approved of the functional change.

The code changes are committed on the JRUBY-6785 branch, ready to be merged as soon as Yoko gives her blessing.

OK, Yoko, I merged the code since you agreed to the functional change. I am confident that it is good.

Uwe, I have a objection about this change.

You changed the feature of API, which will confuse users.

When people evaluate "def my_method; end" only, a return value will be null. Released versions don't require users to change receiver to container.getTopSelf(). Please don't change test as much as possible.

I'll fix those.

Yoko added a new method runRubyMethod with the new behavior. It is good!

I think I will widen the version of runRubyMethod to allow for return type and block so we cover the most general case. This version can be used for the more simple cases as well, and we can add convenience versions later if we want.

I'll add a version of runRubyMethod without Block for easier use with reflection since all signature classes except Block are in the standard Java library.

The new runRubyMethod method solves this nicely.