Fix for parsing "null" values for auto-value objects.

[radzio]

No description provided.

[rharter]

Thanks for the PR. It looks like this caused the tests to fail, and also needs tests for your addition.

[radzio]

@rharter no problem. I didn't updated tests for this. But I've tested it manually and it's working like a charm :-)

[rharter]

@radzio Are you planning to add tests for your changes? I won't be merging in untested code.

[R4md4c]

Hello @radzio,

Are you planning to add tests for this fix? I'm interested in merging this PR. If you don't have time I can step in to write the tests.

[rharter]

@R4md4c Are you still up for writing tests for this and rebasing it?

[R4md4c]

@rharter Yes, I'm still up for it, but I'm wondering whether I should open a new pull request or I use the current pull request?

[rharter]

You can always check out his branch into your own fork and make a new PR.

[muddin1]

@rharter I use nullSafe() in my custom AutoValueTypeAdapterFactory, but now that AutoValueGsonTypeAdapterFactory is introduced in 0.3.0, I can't really use the generated implementation because it doesn't include nullSafe(). Is this pull request going to fix that?

[R4md4c]

I tried to write a test for this PR before applying the patch (after rebasing with upstream) to check what problem it does solve, but I realized that it doesn't solve anything when trying to read a null auto value object from the JSON string as it reads it without a problem.

Perhaps I misunderstood what problem this PR solves?

Here is the test method

   @Test
    public void testReadingNullAutoValueObject() throws Exception {
        Gson gson = new GsonBuilder()
                .registerTypeAdapterFactory(new PersonTypeAdapterFactory())
                .create();
        Person person = Person.builder()
                .name("Piasy")
                .gender(1)
                .age(23)
                .build();
        // Notice the null facility. 
        String fromJson = "{\"name\":\"Piasy\",\"gender\":1,\"age\":23,\"facility\":null}";
        Person fromJsonPerson = gson.fromJson(fromJson, Person.class);

        Assert.assertEquals(person, fromJsonPerson);
        Assert.assertNull(person.facility());
    }

Here is what I added to the Person class.

   @Nullable
    public abstract Facility facility(); // An AutoValue object that contains an integer.