Typo in error message from AbstractCommandSpecProcessor#extractTypedMember(Element, String)?

[rgoldberg]

I think there's another typo in the error message from AbstractCommandSpecProcessor#extractTypedMember(Element, String).

It currently outputs:

"Can only process %s annotations on fields, methods and method parameters, not on %s"

But the element.getKind() == ElementKind.PARAMETER check is commented, so I think the correct message should be:

"Can only process %s annotations on fields and methods, not on %s"

Or maybe the element.getKind() == ElementKind.PARAMETER should be uncommented…

As an aside, I also think the code should use a switch statement instead of chained ifs.

I can make a PR, but just wanted to check first.

[remkop]

Thank you for raising this!
I'll take a look when I get to my PC.

[remkop]

I had a quick look, and it seems that @Option-annotated method parameters are handled in AbstractCommandSpecProcessor#buildOptionsAndPositionalsFromMethodParameters.

I suspect that the extractTypedMember method is not called for annotated elements other than fields and methods.
There is a test for @Option-annotated method parameters: picocli.annotation.processing.tests.AbstractCommandSpecProcessorTest#testCommandWithMixin, and this test does not result in a compiler error.

I did not look in more detail, however.

I am going to leave this error message as it is for now; the error message itself is correct (for example, if a class is annotated with @Option, this error message would be shown, and it would be useful to have it state all valid places where the @Option annotation can be used).

[rgoldberg]

I got the error when I annotated a Kotlin primary constructor parameter with @Parameters:

error: Cannot only process @Parameters annotations on fields, methods and method parameters, not on PARAMETER
    java.lang.String software, @org.jetbrains.annotations.NotNull

It's saying that @Parameters can only be processed on a, b & method parameters, but not on PARAMETER. Since PARAMETER is a method parameter, the message is incorrect.

[remkop]

I got the error when I annotated a Kotlin primary constructor parameter with @Parameters:

Oh I see, interesting. So this is related to #1195.

You could try uncommenting the || element.getKind() == ElementKind.PARAMETER) { condition in extractTypedMember.

Also, (and this may not be important, but) buildOptionsAndPositionalsFromMethodParameters has some extra logic for calculating position for @Parameters elements that do not have an explicit index set. The extractTypedMember does not have that logic. (But it may not be needed, not sure). If it is possible to invoke buildOptionsAndPositionalsFromMethodParameters for constructors, that may be good - but this is just a random thought, I have not looked at the implications of doing this.

[rgoldberg]

Yep, I saw this while investigating #1195.

I'm not trying to change this now to implement #1195.

The current error output must be incorrect, since it says that the annotation can be processed on method parameters, but then says it cannot be processed on PARAMETER. But PARAMETER is a method parameter.

Unless I've completely missed something…

[remkop]

Yes, good point.
I improved the error message to clarify that currently only parameters in @Command-annotated methods are supported.