threequals is called at the class level

threeequals.rb

module ModuleWithSelf
  def self.===(obj)
    obj === "blah"
  end
end

module ModuleNoSelf
  def ===(obj)
    obj === "blah"
  end
end

class ClassWithSelf
  def self.===(obj)
    obj === "blah"
  end
end

class ClassNoSelf
  def ===(obj)
    obj === "blah"
  end
end

# this returns true
if ModuleWithSelf === "blah"
  puts "module with self worked"
else
  puts "module with self FAILED"
end

# this returns false
if ModuleNoSelf === "blah"
  puts "module no self worked"
else
  puts "module no self FAILED"
end

# this returns true, rest return false
if ClassWithSelf === "blah"
  puts "class with self worked"
else
  puts "class with self FAILED"
end

if ClassNoSelf === "blah"
  puts "class no self worked"
else
  puts "class no self FAILED"
end

if ModuleWithSelf === "blee"
  puts "module with self FAILED"
else
  puts "module with self worked"
end

if ModuleNoSelf === "blee"
  puts "module no self FAILED"
else
  puts "module no self worked"
end

if ClassWithSelf === "blee"
  puts "class with self FAILED"
else
  puts "class with self worked"
end

if ClassNoSelf === "blee"
  puts "class no self FAILED"
else
  puts "class no self worked"
end