RandomizerProxy.invoke will throw an exception if the Supplier passed to RandomizerProxy.asRandomizer is defined as package private or stricter

[LucasAndersson]

Hi

It was a bit hard to write a good title, I'll try my best to explain the issue.

I noticed that RandomizerProxy.invoke threw a IllegalAccessException when I passed a Supplier as a lambda to EnhancedRandomBuilder.randomize. I'm not completely sure but I think the java compiler desugars lambdas to anonymous inner classes which in turn are transformed into package private inner classes. If you change RandomizerProxyTest.theRandomizerProxyShouldBehaveLikeTheSupplier to use a lambda the test will pass. I think this is because RandomizerProxyTest and RandomizerProxy are both in the same package, if you move RandomizerProxyTest to another package the exception I was talking about earlier is thrown and the test fails.

You could just pass Randomizer instead of Supplier and everything would be fine but I like the semantics of the latter when I want to return something that isn't actually random and if you already support Supplier then you might as well support them as lambdas as well.

I hope you understood my explanation, it's a bit hard and confusing to explain. I have a solution for this problem and I'm ready to make a PR if you want. I think it will be easier to understand if you read my PR.

Thanks for this great library by the way, I use it all the time.

[PascalSchumacher]

Hi Lucas,

thanks for reporting.

If I understand you correctly the issue is that this:

@Test
public void test() {
    EnhancedRandom random = EnhancedRandomBuilder.aNewEnhancedRandomBuilder()
        .randomize(String.class, (Supplier<String>) ()-> "test").build();

    assertThat(random.nextObject(String.class)).isEqualTo("test");
}

fails with:

io.github.benas.randombeans.api.ObjectGenerationException: Unable to generate a random instance of type class java.lang.String
	at io.github.benas.randombeans.EnhancedRandomImpl.doPopulateBean(EnhancedRandomImpl.java:128)
	at io.github.benas.randombeans.EnhancedRandomImpl.nextObject(EnhancedRandomImpl.java:77)
	at com.test.RandomizerProxyTest.test(RandomizerProxyTest.java:41)
Caused by: java.lang.reflect.UndeclaredThrowableException
	at com.sun.proxy.$Proxy4.getRandomValue(Unknown Source)
	at io.github.benas.randombeans.EnhancedRandomImpl.doPopulateBean(EnhancedRandomImpl.java:99)
	... 25 more
Caused by: java.lang.IllegalAccessException: Class io.github.benas.randombeans.RandomizerProxy can not access a member of class com.test.RandomizerProxyTest$$Lambda$1/1100439041 with modifiers "public"
	at sun.reflect.Reflection.ensureMemberAccess(Reflection.java:102)

While this:

@Test
public void test() {
    EnhancedRandom randomizer = EnhancedRandomBuilder.aNewEnhancedRandomBuilder()
        .randomize(String.class, (Randomizer<String>) ()-> "test").build();

    assertThat(randomizer.nextObject(String.class)).isEqualTo("test");
}

works fine.

I think both ways should work.

A pull request with a fix is very welcome.

[LucasAndersson]

That is correct, with the exception that your first snippet actually works as long as it's located in the same package as RandomizerProxy. I'll create a PR once I'm home from work.