Bug #16438: Check warning messages for Ruby 2.7

• Status: Closed
• Assignee: matz (Yukihiro Matsumoto)
• Target version: 2.7
• Backport: 2.5: UNKNOWN, 2.6: UNKNOWN

[ko1 (Koichi Sasada)]

Please check Ruby 2.7 new introduced warning messages.

• deprecation warning

def foo(**kw)
end

foo({}) #=> test.rb:4: warning: The last argument is used as the keyword parameter
        #   test.rb:1: warning: for `foo' defined here; maybe ** should be added to the call?
# deafult: on

_1 = 2
#=>
# t.rb:1: warning: `_1' is used as numbered parameter

# default: on

def _1; end
#=> test.rb:1: warning: `_1' is used as numbered parameter

# deafult: on
# added at Today!!

def foo
  proc.call #=> 1
end

foo{p 1}
#=>
# t.rb:2: warning: Capturing the given block using Kernel#proc is deprecated; use `&block` instead
# 1

# default: on

$; = //
#=> t.rb:1: warning: non-nil $; will be deprecated

$, = ''
#=> t.rb:2: warning: non-nil $, will be deprecated

# default: on

   def foo
     class << Object.new
       yield
     end
   end
   foo { p :ok } #=> warning: `yield' in class syntax will not be supported from Ruby 3.0.

# default: on

require 'open-uri'
open('http://atdot.net')
#=> test.rb:2: warning: calling URI.open via Kernel#open is deprecated, call URI.open directly or use URI#open

# default: on

• experimental feature

$ ./miniruby -e 'case 1; in 1; end'
-e:1: warning: Pattern matching is experimental, and the behavior may change in future versions of Ruby!

# default: on

[osyo (manga osyo)]

def _1; end
#=> test.rb:1: warning: `_1' is used as numbered parameter

Warn by parameter name instead of method name.

Became warning.

# warning: `_1' is used as numbered parameter
def _1; end

# warning: `_1' is used as numbered parameter
def hoge(_1); end

[ko1 (Koichi Sasada)]

$SAFE = 1
#=> t.rb:1: warning: $SAFE will become a normal global variable in Ruby 3.0

no warning

pls check current master.

[osyo (manga osyo)]

pls check current master.

Sorry, became warning.

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset git|a8bddb3a189545a2bef8ee7cffdb328d8de7974c.

---

Refined the warning message for numbered-parameter like variables

[Bug #16438]

[ko1 (Koichi Sasada)]

At developer's meeting, the followings are proposed. They will be merged into Ruby 2.7 RC2.

def foo(**kw)
end

foo({})

# current:
#=> test.rb:4: warning: The last argument is used as the keyword parameter
#   test.rb:1: warning: for `foo' defined here; maybe ** should be added to the call?

# modified (conclusion):
#=> test.rb:4: warning: The last argument is used as keyword parameters; maybe ** should be added to the call
#   test.rb:1: warning: The called method `foo' is defined here

# t.rb:1: warning: `_1' is used as numbered parameter
->
# t.rb:1: warning: `_1' is reserved for numbered parameter; consider another name

#=> t.rb:1: warning: non-nil $; will be deprecated
=>
#=> t.rb:1: warning: `$;' is deprecated

[puchuu (Andrew Aladjev)]

Hello. I can't understand why setting OFS to not nil value was deprecated. I want to simulate print method behaviour and I am using $OUTPUT_FIELD_SEPARATOR between objects. Than I want to test this method, so I am settings OFS to not nil value in tests. Ruby 2.7.0 throws deprecated warning.

[puchuu (Andrew Aladjev)]

I see the only one way to fix this deprecation. Change write(*objects) signature to print(*objects, field_separator: $OUTPUT_FIELD_SEPARATOR, record_separator: $OUTPUT_RECORD_SEPARATOR) and test print by passing separators directly. Will ruby change print signature in the same way?