It's pretty common to want to apply the various fmt.Fprint... functions
to our two output streams, and so to make that much less noisy at the
callsite here we have a small number of very thin wrappers around the
underlying fmt package functionality.
Although we're aiming to not have too much abstraction in this "terminal"
package, this seems justified in that it is only a very thin wrapper
around functionality that most Go programmers are already familiar with,
and so the risk of this causing any surprises is low and the improvement
to readability of callers seems worth it.
This is to allow convenient testing of functions that are designed to work
directly with *terminal.Streams or the individual stream objects inside.
Because the InputStream and OutputStream APIs expose directly an *os.File,
this does some extra work to set up OS-level pipes so we can capture the
output into local buffers to make test assertions against. The idea here
is to keep the tricky stuff we need for testing confined to the test
codepaths, so that the "real" codepaths don't end up needing to work
around abstractions that are otherwise unnecessary.
This is a helper package that creates a very thin abstraction over
terminal setup, with the main goal being to deal with all of the extra
setup we need to do in order to get a UTF-8-supporting virtual terminal
on a Windows system.
Martin Atkins