Spoon and Nullable

[MartinWitt]

Currently, spoon has non @Nullable annotation and we only document nullablility in the Javadoc. Why don't we adopt https://jspecify.dev/docs/start-here and migrate over the time to an annotated library? An alternative is @Contract from JB, but these are only supported in IJ and are way harder to write.

[tenax66]

I am interested in this proposal.
If we adopt jspecify, should we start working with version 0.3 instead of waiting for version 1.0?

[MartinWitt]

We start with 0.3 and can update it later. The goal is to start annotating spoon and waiting for the 1.0 release can take years. A good starting point are methods with null documented in their javadoc for return values.

[MartinWitt]

A noteworthy alternative is using https://www.jetbrains.com/help/idea/annotating-source-code.html. These annotations are at least stable and do the same. But there could be some future where everyone uses jspecify. And the qodana rule for this is: NullableProblems.

[tenax66]

A good starting point are methods with null documented in their javadoc for return values.

I will see what I can do about this.

[tenax66]

I looked for the word "null" in @return tags in Javadoc of the spoon-core code.
Here are the counts for each package.
We may be able to start from these.

package	count
spoon	1
spoon.compiler	1
spoon.metamodel	3
spoon.pattern.internal	2
spoon.pattern.internal.matcher	3
spoon.pattern.internal.node	1
spoon.pattern.internal.parameter	2
spoon.reflect.code	3
spoon.reflect.declaration	12
spoon.reflect.factory	7
spoon.reflect.path	1
spoon.reflect.reference	8
spoon.reflect.visitor	5
spoon.support.compiler	1
spoon.support.compiler.jdt	4
spoon.support.modelobs	1
spoon.support.reflect.eval	1
spoon.support.reflect.reference	1
spoon.support.sniper.internal	3
spoon.support.util	2
spoon.support.util.internal	1
spoon.support.visitor	3
spoon.support.visitor.java	2

[MartinWitt]

Yes, this is a good starting point. 👍

[tenax66]

Create a task list to add @Nullable annotations to the classes under each package.

• spoon
• spoon.compiler
• spoon.metamodel
• spoon.pattern.internal
• spoon.pattern.internal.matcher
• spoon.pattern.internal.node
• spoon.pattern.internal.parameter
• spoon.reflect.code
• spoon.reflect.declaration
• spoon.reflect.factory
• spoon.reflect.path
• spoon.reflect.reference
• spoon.reflect.visitor
• spoon.support.compiler
• spoon.support.compiler.jdt
• spoon.support.modelobs
• spoon.support.reflect.eval
• spoon.support.reflect.reference
• spoon.support.sniper.internal
• spoon.support.util
• spoon.support.util.internal
• spoon.support.visitor
• spoon.support.visitor.java

[tenax66]

As I mentioned in #5424 , JavaReflectionTreeBuilderTest fails when @Nullable is applied to classes under some specific packages. (like spoon.reflect.code, spoon.reflect.declaration).

Can we remove @Nullable and @NonNull from the target of the test? Since these are TYPE_USE annotations, so JavaReflectionTreeBuilder does not build them.