internal/app: check username validation

This stuff should be hardcoded in libc, but check it anyway.

Signed-off-by: Ophestra <cat@gensokyo.uk>

1 files changed, 26 insertions, 0 deletions

diff --git a/internal/app/username_test.go b/internal/app/username_test.go
new file mode 100644
index 00000000..15f15a4c
--- /dev/null
+++ b/internal/app/username_test.go
@@ -0,0 +1,26 @@
+package app
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestIsValidUsername(t *testing.T) {
+	t.Run("long", func(t *testing.T) {
+		if isValidUsername(strings.Repeat("a", sysconf(_SC_LOGIN_NAME_MAX))) {
+			t.Errorf("isValidUsername unexpected true")
+		}
+	})
+
+	t.Run("regexp", func(t *testing.T) {
+		if isValidUsername("0") {
+			t.Errorf("isValidUsername unexpected true")
+		}
+	})
+
+	t.Run("valid", func(t *testing.T) {
+		if !isValidUsername("alice") {
+			t.Errorf("isValidUsername unexpected false")
+		}
+	})
+}