Jukito issue 34: Provider bindings in @Provides methods

package org.jukito.provbug;

import javax.inject.Inject;
import javax.inject.Provider;

import com.google.inject.AbstractModule;
import com.google.inject.Guice;
import com.google.inject.Injector;
import com.google.inject.Provides;

import org.jukito.JukitoModule;
import org.jukito.JukitoRunner;
import org.junit.Test;
import org.junit.runner.RunWith;
import static org.junit.Assert.assertEquals;

/**
 * Uncomment exactly one of the lines marked A, B, or C and run as a test
 * or as a main program.
 * <p>
 * When A is uncommented, the test passes and the main program runs with
 * no problem, because we aren't binding the Provider<Integer> in a
 * @Provides method.
 * <p>
 * When B is uncommented, the test passes and the main program runs with
 * no problem, because String is injected with Integer rather than a
 * Provider<Integer>.
 * <p>
 * When C is uncommented, the test gets an error but the main program
 * still runs with no problem. This is the issue 34 bug: Guice supports
 * binding to Provider in @Provides methods, but Jukito doesn't.
 */
@RunWith(JukitoRunner.class)
public class ProvidesBugTest {

    public static void main(String... args) {
        String s = Guice.createInjector(new Mod2()).getInstance(String.class);
        assert "123".equals(s) : "problem: should be 123";
        System.out.println("no problem");
    }

    public static class Mod1 extends JukitoModule {
        @Override protected void configureTest() {
            install(new Mod2());
        }
    }

    public static class Mod2 extends AbstractModule {
        @Override protected void configure() {
            bind(Integer.class).toInstance(123);
            bind(String.class).toProvider(StringProvider.class);      // A
        }

        static class StringProvider implements Provider<String> {
            final Provider<Integer> ip;
            @Inject StringProvider(Provider<Integer> ip) { this.ip = ip; }
            public String get() {
                return ip.get().toString();
            }
        }

        //@Provides                                                     // B
        String getStringFromInt(Integer i) {
            return i.toString();
        }

        //@Provides                                                     // C
        String getStringFromIntProvider(Provider<Integer> i) {
            return i.get().toString();
        }
    }

    @Test public void foo(String s) {
        assertEquals("123", s);
    }
}