Actions adore keyword arguments

[JoshCheek]

Consider this task:

task :t, [:arg] do |task, arg: 'default_value'|
  emotion = "\e[32m^_^\e[0m"
  emotion = "\e[31mt.t\e[0m" if ARGV[0] =~ /t\[(.*)\]$/ && $1 != arg
  puts "task #{task.name.inspect} got #{arg.inspect} #{emotion}"
end

Run this on your machine right now and you'll see the task is in tears. But this commit turns tearful eyes into smiling ones, observe:

$ rake t
task "t" got "default_value" ^_^
$ rake t[custom_value]
task "t" got "default_value" t.t

$ ruby -Ilib exe/rake t
task "t" got "default_value" ^_^
$ ruby -Ilib exe/rake t[custom_value]
task "t" got "custom_value" ^_^

It accomplishes this by always invoking the action in the same way. Previously, Rake invoke the action with different argument structures based the arity.

case act.arity
when 1
  act.call(self)
else
  act.call(self, args)
end

I assume it's expecting one of these:

proc { |task| }.arity           # => 1
proc { |task, options| }.arity  # => 2

However this leads numerous task signatures to be invoked incorrectly. Eg, consider the case of our tearful task above, here is why it cries.

proc { |task, arg: 'default_value'| }.arity # => 1

The solution is nice and easy: always invoke the block the same way.

Why was this ever a thing at all, then? Looks like it was added in 2007 about a month after Ruby 1.8.6 was released. 925fbb8 Probably something was just different back then, eg the (difference) between lambdas and procs was whether you did prc.call or prc.yield

[nobu]

You need +1 to __LINE__

[nobu]

A failure in jruby-head seems a bug of jruby.

[n054]

@JoshCheek let me see if I can help with Travis intigration. @n054

[JoshCheek]

@n054 I'd appreciate it ^_^

[n054]

@JoshCheek investigating the Travis test shows test#482.1-482.7 are passing.
Test#482.8&482.9 show TestRakeTaskWithArguments#test_actions_adore_keywords:
ArgumentError:missing keyword: reqr

[JoshCheek]

Looks like it's a JRuby bug. Surprising, maybe I just use keywords a lot more than other people?

Here's the program:

$ cat f.rb
p proc { |a, b:| [a, b] }.call("a-val", b: "b-val")

MRI handles it.

$ chruby 2.3.2
$ ruby -v
ruby 2.3.2p217 (2016-11-15 revision 56796) [x86_64-darwin15]
$ ruby f.rb
["a-val", "b-val"]

Rbx handles it

$ chruby rbx
$ rbx -v
rubinius 3.60 (2.3.1 5d5e49f7 2016-09-21 3.9.0) [x86_64-darwin15.6.0]
$ rbx f.rb
["a-val", "b-val"]

JRuby blows up.

$ chruby jruby
$ jruby -v
jruby 9.1.5.0 (2.3.1) 2016-09-07 036ce39 Java HotSpot(TM) 64-Bit Server VM 25.71-b15 on 1.8.0_71-b15 +jit [darwin-x86_64]
$ jruby f.rb
ArgumentError: missing keyword: b
  block in f.rb at f.rb:-1
         <main> at f.rb:1

[JoshCheek]

Looks @nobu beat me to reporting: jruby/jruby#4344