chore: plenary tests POC: add make entry, specify tests

scripts/test.sh

@@ -2,16 +2,19 @@
 
 set -e
 
-# TODO add ability for user to specify a test file or directory
-
-# TODO clone plenary
-
 DIR_REPO="$(git rev-parse --show-toplevel)"
 export DIR_REPO
 
 DIR_PLENARY="${DIR_REPO}/plenary.nvim"
 export DIR_PLENARY
 
+if [ "${#}" -eq 1 ]; then
+	TEST_NAME="${1}"
+else
+	TEST_NAME="tests"
+fi
+export TEST_NAME
+
 nvim --headless \
 	--clean \
 	-u "${DIR_REPO}/tests/minimal_init.lua" \