brew/Library/Homebrew/test/support/helper/output_as_tty.rb
2017-07-10 00:09:32 +02:00

85 lines
2.0 KiB
Ruby

require "delegate"
module Test
module Helper
module OutputAsTTY
# This is a custom wrapper for the `output` matcher,
# used for testing output to a TTY:
#
# expect {
# print "test" if $stdout.tty?
# }.to output("test").to_stdout.as_tty
#
# expect {
# # command
# }.to output(...).to_stderr.as_tty.with_color
#
class Output < SimpleDelegator
def matches?(block)
return super(block) unless @tty
colored_tty_block = lambda do
instance_eval("$#{@output}").extend(Module.new do
def tty?
true
end
alias_method :isatty, :tty?
end)
block.call
end
return super(colored_tty_block) if @colors
uncolored_tty_block = lambda do
instance_eval <<-EOS
begin
captured_stream = StringIO.new
original_stream = $#{@output}
$#{@output} = captured_stream
colored_tty_block.call
ensure
$#{@output} = original_stream
$#{@output}.print Tty.strip_ansi(captured_stream.string)
end
EOS
end
super(uncolored_tty_block)
end
def to_stdout
@output = :stdout
super
self
end
def to_stderr
@output = :stderr
super
self
end
def as_tty
@tty = true
return self if [:stdout, :stderr].include?(@output)
raise "`as_tty` can only be chained to `stdout` or `stderr`."
end
def with_color
@colors = true
return self if @tty
raise "`with_color` can only be chained to `as_tty`."
end
end
def output(*args)
core_matcher = super(*args)
Output.new(core_matcher)
end
end
end
end