From: Justin Collins <justincollins@...>
Date: 2010-02-12T02:48:03+09:00
Subject: Re: Test script

Antoine Makhassak wrote:
> Richard Conroy wrote:
>   
>> What you are attempting to do here is an acceptance test, not a unit 
>> test.
>> Test::Unit will facilitate both in this case.
>>
>> What you want to do is call your program from the shell, with all of the
>> correct
>> arguments, and assert that your program gives the correct output.
>>
>> THen do it again with random or incorrect arguments and verify that your
>> program gives the correct error response or exit code.
>>
>> You will also need to verify the programs side effects. (Any files that 
>> it
>> creates,
>> deletes or touches),
>>     
>
>
>
> Yes I know, but I need to call my program with different arguments 
> "automatically" i.e. I do not want to manually launch my program for 
> each test. Can you tell me pls exactly what to enter in my .rb source 
> file or a shell script / batch file so that it automatically makes the 
> calls and outputs the results?
> Thank you
>   

You can use backticks (``) to call your program and return the output as 
a string. You can use $?.exitstatus to see if it exited with an error. 
You can also use string interpolation for arguments.

For example:

irb(main):001:0> `echo hello`
=> "hello\n"
irb(main):002:0> $?.exitstatus
=> 0
irb(main):003:0> world = "world"
=> "world"
irb(main):004:0> `echo #{world}`
=> "world\n"


-Justin