setup.sh/setup: show usage when no argument is given (#2540)

setup.sh

@@ -236,4 +236,5 @@ function _main
   return 0
 }
 
+[[ -z ${1:-} ]] && set 'help'
 _main "${@}"

target/bin/setup

@@ -167,4 +167,9 @@ function _main
   esac
 }
 
-_main "${@}"
+if [[ -z ${1:-} ]]
+then
+  _usage
+else
+  _main "${@}"
+fi

test/tests.bats

@@ -936,10 +936,10 @@ EOF
 # --- setup.sh ----------------------------------
 # -----------------------------------------------
 
-@test "checking setup.sh: exit with error when no arguments provided" {
+@test "checking setup.sh: show usage when no arguments provided" {
   run ./setup.sh
-  assert_failure
-  assert_line --index 0 --partial "The command '' is invalid."
+  assert_success
+  assert_output --partial "This is the main administration script that you use for all your interactions with"
 }
 
 @test "checking setup.sh: exit with error when wrong arguments provided" {