Add support for non-interactive terminal

[sheerun]

This should fix #869

[sheerun]

Also added a commit that should fix #873

[fson]

tty.isatty(fd) should be passed a file descriptor.

[sheerun]

"A numeric file descriptor", it's correct

[fson]

Right, so 1 is a magical number that means the standard output. Perhaps process.stdout.isTTY would be clearer?

[sheerun]

Sure... I've changed it

[fson]

I was testing this branch and after making a change the terminal screen just went blank. I thought the compiler had got stuck. Why did we change this behavior?

[fson]

Perhaps we could only show The app is running at... after the first compile, but keep showing Compiled successfully! after each successful rebuild?

[sheerun]

Hmm. This should be non-interactive only change. It's to prevent duplicate output in non-interactive terminal. I've just fixed it.

[gaearon]

Can we please simplify this condition by extracting some boolean variables? It's getting crowdy and hard to tell when it's true.

[sheerun]

ok, fixed..

[sheerun]

It should be ready to merge..

[fson]

I tested the non-interactive shell with concurrently. The output after starting the server, changing a file and waiting a few seconds looks like this:

Maybe it's just me, but it feels like the compiler is still recompiling because we print "Compiling..." but never "Compiled successfully!". Can we either remove the "Compiling..." output in non-interactive mode, or alternatively also print "Compiled successfully!" each time compiling has finished?

I'm not normally using a setup like this, so I'm not sure which alternative would be better, but the current behaviour doesn't seem right.

[sheerun]

@fson I've changed code so it always displays "Compiled successfully!". Could we merge?

[fson]

Thanks @sheerun, nice work!