[ENG-120] Disable git hooks when not invoked from a tty

git-hooks-multiplexer

@@ -1,6 +1,13 @@
 #!/usr/bin/env bash
 set -eu -o pipefail
 
+# Ensure we are being invoked from a terminal (ie. tty)
+# We use stderr since git usually doesn't hook a tty up to stdin in the
+# first place and it seems to specifically hook one up to stdout.
+# Hopefully automated scripts attempt to capture stderr and as such
+# it wouldn't be a tty - meaning we shouldn't attempt to run the hooks.
+[[ -t 2 ]] || exit 0
+
 # Determine which git hook is being run and make sure we're not accidentally
 # being called from another multiplexer script.
 # shellcheck disable=2155