Crystal: Passing block to class_property tries to return first assignment in block

[vonKingsley]

The following happened recently on master.
Running this code.

require "logger"
 module Test
   class_property(logger) {
     @@logger ||= begin
       a = 1
       Logger.new(STDOUT)
     end
   } 
   Test.logger.info("logme")
 end

returns class variable '@@logger' of Test must be (Logger | Nil), not Int32

crystal version

Crystal 0.24.0+50 [c9fac5645] (2017-11-14)

LLVM: 4.0.1
Default target: x86_64-apple-macosx

This works correctly in 0.23.1 and worked on 0.24.0 a few days ago so a recent change may have caused this.

[Sija]

Your example shows improper usage of class_property.
The whole point of lazy getter is not to define @@its_cvar by hand...

Proper version is as follows:

require "logger"

module Test
  class_property(logger) { Logger.new(STDOUT) }
end

Test.logger.info "logme"

[Sija]

@jhass I'd suggest removing those tags since it's neither bug nor it's related to the compiler.

[jhass]

Well, how does it get typed as Int32 though? It should expand to

def self.logger
  @@logger ||= begin
    @@logger ||= begin
      a = 1
      Logger.new(STDOUT)
    end
  end
end

The last expression in the inner begin is Logger.new, so the type of the inner begin expression should be Logger, which makes the type of the inner @@logger ||= expression Logger, which makes the type of the outer begin expression Logger, which makes the type of the outer @@logger ||= expression, Logger. Where do I go wrong?

[Sija]

@jhass indeed, you're right! even though included usage of class_property was improper, below code should compile alright...

[vonKingsley]

@Sija you are correct I was using class_property incorrectly. I checked the code and saw the block gets assigned to the class variable. I removed @@logger ||= and my code was working again.

@jhass Thanks for minimizing that code, i now know I was using it incorrectly ,but that particular change in behavior didn't seem right to me.

[vlazar]

Both examples now show

$ crystal test.cr
I, [2019-10-13 20:45:26 +03:00 #26218]  INFO -- : logme

$ crystal --version
Crystal 0.31.1 (2019-10-02)

LLVM: 8.0.1
Default target: x86_64-apple-macosx

[asterite]

@vlazar Yes, thanks! It seems to be working fine now. I don't know what fixed it.