Super simple Scope in Guice

ScopesModule.java

import com.google.inject.*;

import javax.inject.Inject;
import java.lang.annotation.Retention;

import static java.lang.annotation.RetentionPolicy.RUNTIME;

@ScopeAnnotation
@Retention(RUNTIME)
@interface NameScoped {
}

public class ScopesModule extends AbstractModule {

    @Override
    protected void configure() {
        NameScope scope = new NameScope();

        bindScope(NameScoped.class, scope);

        bind(String.class).in(NameScoped.class);
        bind(Greeter.class);
    }
}

class Greeter {

    @Inject
    private String name;

    String greet() {
        return "Hello, " + name;
    }
}

class NameProvider implements Provider<String> {

    private final String name;

    NameProvider(final String name) {
        this.name = name;
    }

    @Override
    public String get() {
        return this.name;
    }
}

class NameScope implements Scope {

    @Override
    public <T> Provider<T> scope(final Key<T> key, final Provider<T> unscoped) {
        return  (Provider<T>) new NameProvider("Joe");
    }
}

ScopesModuleTest.java

import com.google.inject.Guice;
import com.google.inject.Injector;
import org.junit.jupiter.api.Test;

import static org.assertj.core.api.Assertions.assertThat;

class ScopesModuleTest {

    @Test
    public void should_return_object_with_scoped_value() {
        // given
        final ScopesModule scopesModule = new ScopesModule();
        final Injector injector = Guice.createInjector(scopesModule);

        final Greeter instance = injector.getInstance(Greeter.class);
        assertThat(instance).isNotNull();

        final String greet = instance.greet();
        assertThat(greet).isEqualTo("Hello, Joe");
    }
}