add set-ref command and refactor tests

e2e-tests/bash_completion_test.go

@@ -21,7 +21,6 @@ package e2etests_test
 import (
 	"testing"
 
-	"github.com/alecthomas/assert/v2"
 	"github.com/efficientgo/e2e"
 )
 
@@ -31,10 +30,7 @@ func TestE2EBashCompletion(t *testing.T) {
 		"bash-completion",
 		COMMON_SYSTEMS,
 		func(t *testing.T, r e2e.Runnable) {
-			err := r.Exec(e2e.NewCommand(
-				"alr", "install", "--generate-bash-completion",
-			))
-			assert.NoError(t, err)
+			execShouldNoError(t, r, "alr", "install", "--generate-bash-completion")
 		},
 	)
 }