Forum: Ruby-core [ruby-trunk - Feature #7730][Open] Top level variables aren't checked for assigned but unused behavi

Issue #7730 has been reported by agrimm (Andrew Grimm).

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Feature #7730: Top level variables aren't checked for assigned but 
unused behavior
https://bugs.ruby-lang.org/issues/7730

Author: agrimm (Andrew Grimm)
Status: Open
Priority: Normal
Assignee:
Category:
Target version:


In the following code, variable a in the method gets a warning, but 
variable b in top level code doesn't get any warning

    def warning_method
      a = 2
    end

    b = 2
    warning_method

    $ ruby -w no_toplevel_warnings.rb
    no_toplevel_warnings.rb:2: warning: assigned but unused variable - a

It is possible to detect that b is unused if the script is required from 
another script.

I'd like Ruby to be able to detect that b is an assigned but unused 
variable.

Issue #7730 has been updated by nobu (Nobuyoshi Nakada).

File 0001-parse.y-warn-assigned-but-unused-in-toplevel.patch added

Agree except for -e option.
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Feature #7730: Top level variables aren't checked for assigned but 
unused behavior
https://bugs.ruby-lang.org/issues/7730#change-35541

Author: agrimm (Andrew Grimm)
Status: Open
Priority: Normal
Assignee:
Category:
Target version:


In the following code, variable a in the method gets a warning, but 
variable b in top level code doesn't get any warning

    def warning_method
      a = 2
    end

    b = 2
    warning_method

    $ ruby -w no_toplevel_warnings.rb
    no_toplevel_warnings.rb:2: warning: assigned but unused variable - a

It is possible to detect that b is unused if the script is required from 
another script.

I'd like Ruby to be able to detect that b is an assigned but unused 
variable.

Issue #7730 has been updated by ko1 (Koichi Sasada).

Category set to core
Assignee set to nobu (Nobuyoshi Nakada)
Target version set to next minor

Nobu, do you need matz's approval?

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Feature #7730: Top level variables aren't checked for assigned but 
unused behavior
https://bugs.ruby-lang.org/issues/7730#change-35592

Author: agrimm (Andrew Grimm)
Status: Open
Priority: Normal
Assignee: nobu (Nobuyoshi Nakada)
Category: core
Target version: next minor


In the following code, variable a in the method gets a warning, but 
variable b in top level code doesn't get any warning

    def warning_method
      a = 2
    end

    b = 2
    warning_method

    $ ruby -w no_toplevel_warnings.rb
    no_toplevel_warnings.rb:2: warning: assigned but unused variable - a

It is possible to detect that b is unused if the script is required from 
another script.

I'd like Ruby to be able to detect that b is an assigned but unused 
variable.