Project Wide Static Analysis Annotations

[Sxtanna]

This PR adds JetBrains annotations throughout the entire project, including:

• @NotNull
• @Nullable
• @Contract

This addresses a concern originally raised by me here:
#133 (comment)

And later similarly referenced here:
#196

( WIP please don't flame me ❤️ )

[ljacqu]

Seems great! I'll have to get used to the String @NotNull [] notation but saw the same being used in Google Guava.

Heads up btw, I'm planning this in for 1.4.0 as I should release 1.3.0 very soon and I'll have to merge in another branch to master for that release still. I hope that won't cause too many conflicts (it's mainly a smaller refactoring in the YAML file resource)

[Sxtanna]

I'll have to get used to the String @NotNull [] notation but saw the same being used in Google Guava.

Yeah, and especially considering that only marks the array object itself as not null, if you want to say both the object is not null AND the array should only contains non null values it's @NotNull String @NotNull [].

What a beauty. 😭

[ljacqu]

Thanks for doing this! I'm clicking through the files and it looks great. I have two questions

• do you think @ParametersAreNonnullByDefault would be picked up by IntelliJ enough that sometime we could revert to using that and only @Nullable? (Not to do it in this PR, don't get me wrong, just interested in an opinion)
• the new annotations project is now packaged into the project and no longer set as provided. Do you know if that impacts the JAR size by much?

[Sxtanna]

do you think @ParametersAreNonnullByDefault would be picked up by IntelliJ enough that sometime we could revert to using that and only @Nullable? (Not to do it in this PR, don't get me wrong, just interested in an opinion)

Judging by their consistent unwillingness, probably not:
JetBrains/java-annotations#60
JetBrains/java-annotations#18

the new annotations project is now packaged into the project and no longer set as provided. Do you know if that impacts the JAR size by much?

This was actually a mistake, none of the annotations have a runtime retention policy anyway. Setting the dependency to provided is perfectly fine.

(for reference though, shading the annotations adds ~26KB to the jar size)

[ljacqu]

Thanks for addressing everything! Taking this over now, and will hopefully get used to the new annotations concept 😄✨