Build Your Own Di Library (Part 1)

TinyInjector.java

class TinyInjector {
    public <T> T get(Class<T> klass) {
        try {
            return klass.newInstance();
        } catch (InstantiationException | IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }
}

Zero.java

class Zero {
    public String say() {
        return "Hello, world!";
    }
}

ZeroTest.java

class ZeroTest {
    @Test
    void canInstantiateAZeroArgumentClass() {
        var injector = new TinyInjector();

        var instance = injector.get(Zero.class);

        assertThat(instance.say(), is("Hello, world!"));
    }
}