NullAway does not recognize null-check methods properly

[uber]

NullAway does not recognize null-check methods properly

[bejibx]

In addition to these options, NullAway will look for any classes implementing the com.uber.nullaway.LibraryModels interface...

It seems I have to use compile dependency instead of annotationProcessor to do so, which will add a lot of uneccessary dependencies (including huge Guava library) to my project, which I want to avoid.

[msridhar]

NullAway is not able to reason across procedure calls to prove the original example safe. Doing so could slow the tool down considerably. That said, is this a well-known StringUtils class from a standard library? If so we could maybe add a library model to catch this case.

[bejibx]

No, this is my own utility class. Actually, I used TextUtils#isEmpty(CharSequence) initially, but migrate to my own method because IntelliJ IDEA code inspections running on CI server were not able to analyze these situations properly. If NullAway is ok with android method I can potentially migrate back (which I don't want to do, because it is a LOT of code), but there are many other places in app, where similar null-checking logic involved. I also don't like to supress those warnings because I have to supress whole method, which is ok for above example, but may be unacceptable for larger methods. Maybe add an option to supress warning using comments similar to how Lint inspections being supressed?

//noinspection NullAway
return StringUtils.isEmptyOrNull(text) ? "Hello World!" : text;

[msridhar]

I think a good option here would be for you to add your own library model actually. The process is documented here, but the docs are a bit sparse. We should add a sample library model to show how it's done. We'll work on that, but if you figure it out in the meantime let us know.

[msridhar]

@bejibx I just added a sample library model on master; see #53. It's used by the sample app just by adding an annotation processor dependency; no need to pollute your app's classpath. Does this look like a reasonable solution?

[msridhar]

btw for targeted suppressions, you can "downcast" any particular expression from @Nullable to @NonNull with a utility method; see here

[msridhar]

Gonna close this out as I think it's solved; @bejibx please let us know if you need further help

[bejibx]

Sorry for late response, yeah, I managed to fix those errors by implementing LibraryModels in separate module.