Need better interactive test driver

[mqudsi]

I have a series of tests that I keep in my head and run manually when testing job control. I can't use the existing testing framework for these because it's incapable of interacting with child processes in any of the modes (C++, fish script, or expect).

As the simplest example, we need a scripted way to do this in an interactive fish session:

• Run fish
• Start foo | less
• Send ^Z to the foreground job
• Run a fish command and error if we hang here

Any suggestions on how this might be accomplished? The Tcl/expect scripts can't do the first bolded step, or at least, I can't figure out how to get them to do it. Input seems to always be directed either to the (local) console or to fish itself, but does not reach child procs.

[zanchey]

Can you signal the process rather than sending Ctrl-Z?

[mqudsi]

@zanchey good suggestion, but I don't think so since that would require some form of backgrounding in order to get the fish instance to return $last_pid and to send the signal while less is in the foreground. Additionally, for testing the most basic assumptions of job control depending on complex bg/fg behavior and executing multiple jobs at once is probably not the way to go.

In all cases, that was just an example of something I needed to do. There are cases where it's necessary to do other things, such as verify that stdin is correctly connected to the right job, etc.

[faho]

Okay, we have pexpect now which is nicer to work with than expect, because it's now python rather than tcl.

I'm calling that good enough for now.

[zanchey]

Can we implement @mqudsi's tests above now?

[faho]

Something like

sendline("cat | cat")
sendline("foo")
expect_str("foo")
sendline("set -l foo bar; echo $foo")
expect_str("set -l foo bar; echo $foo")
send("\x1A")
sendline("set -l foo bar; echo $foo")
expect_str("bar")
expect_prompt()

should do? It seems to work in my tests - The fish script before the \x1A (ctrl-z) and comes back literally, and the script after is interpreted.

[mqudsi]

Indeed, that looks great!