My Ruby program reads lines from stdin
and uses puts
to print to stdout
(the terminal). Can I use RSpec to test the reads and writes? Can I inject a string to my program like it was written in stdin
and at the same time check the output?
line = STDIN.read.chomp.split
Also, I have the reads and writes in a loop, until line[0]
is "quit". Can I test while the loop is running or should I call subject.read_in
and subject.write_out
?
You can use mocks and have the method called more than once by listing multiple values in the and_return()
method. These will be returned, one on each call, in the order given.
STDIN.should_receive(:read).and_return("Your string")
STDIN.should_receive(:read).and_return("value1", "value2", "value3")
You can do similar things with STDOUT:
STDOUT.should_receive(:puts).with("string")
See the RSpec mocking documentation for more information.
With RSpec 3.0, there is output matcher for this purpose:
expect { my_method }.to output("my message").to_stdout
expect { my_method }.to output("my error").to_stderr
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With