Captures the given stream and returns it:
stream = capture(:stdout) { puts "Cool" } stream # => "Cool\n"
# File lib/active_support/core_ext/kernel/reporting.rb, line 70 def capture(stream) begin stream = stream.to_s eval "$#{stream} = StringIO.new" yield result = eval("$#{stream}").string ensure eval("$#{stream} = #{stream.upcase}") end result end
#class_eval on an object acts like singleton_class.class_eval.
# File lib/active_support/core_ext/kernel/singleton_class.rb, line 10 def class_eval(*args, &block) singleton_class.class_eval(*args, &block) end
Starts a debugging session if ruby-debug has been loaded (call rails server –debugger to do load it).
# File lib/active_support/core_ext/kernel/debugger.rb, line 4 def debugger message = "\n***** Debugger requested, but was not available (ensure ruby-debug is listed in Gemfile/installed as gem): Start server with --debugger to enable *****\n" defined?(Rails) ? Rails.logger.info(message) : $stderr.puts(message) end
Sets $VERBOSE to true for the duration of the block and back to its original value afterwards.
# File lib/active_support/core_ext/kernel/reporting.rb, line 17 def enable_warnings with_warnings(true) { yield } end
Silences both STDOUT and STDERR, even for subprocesses.
quietly { system 'bundle install' }
# File lib/active_support/core_ext/kernel/reporting.rb, line 88 def quietly silence_stream(STDOUT) do silence_stream(STDERR) do yield end end end
Silences any stream for the duration of the block.
silence_stream(STDOUT) do puts 'This will never be seen' end puts 'But this will'
# File lib/active_support/core_ext/kernel/reporting.rb, line 41 def silence_stream(stream) old_stream = stream.dup stream.reopen(RbConfig::CONFIG['host_os'] =~ /mswin|mingw/ ? 'NUL:' : '/dev/null') stream.sync = true yield ensure stream.reopen(old_stream) end
Sets $VERBOSE to nil for the duration of the block and back to its original value afterwards.
silence_warnings do value = noisy_call # no warning voiced end noisy_call # warning voiced
# File lib/active_support/core_ext/kernel/reporting.rb, line 12 def silence_warnings with_warnings(nil) { yield } end
Returns the object's singleton class.
# File lib/active_support/core_ext/kernel/singleton_class.rb, line 3 def singleton_class class << self self end end
Blocks and ignores any exception passed as argument if raised within the block.
suppress(ZeroDivisionError) do 1/0 puts "This code is NOT reached" end puts "This code gets executed and nothing related to ZeroDivisionError was seen"
# File lib/active_support/core_ext/kernel/reporting.rb, line 58 def suppress(*exception_classes) begin yield rescue Exception => e raise unless exception_classes.any? { |cls| e.kind_of?(cls) } end end
Sets $VERBOSE for the duration of the block and back to its original value afterwards.
# File lib/active_support/core_ext/kernel/reporting.rb, line 22 def with_warnings(flag) old_verbose, $VERBOSE = $VERBOSE, flag yield ensure $VERBOSE = old_verbose end