fix: ensure users imported from LDAP have fields validated (#923)

backend/internal/dto/validations_test.go

@@ -0,0 +1,58 @@
+package dto
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestValidateUsername(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected bool
+	}{
+		{"valid simple", "user123", true},
+		{"valid with dot", "user.name", true},
+		{"valid with underscore", "user_name", true},
+		{"valid with hyphen", "user-name", true},
+		{"valid with at", "user@name", true},
+		{"starts with symbol", ".username", false},
+		{"ends with non-alphanumeric", "username-", false},
+		{"contains space", "user name", false},
+		{"empty", "", false},
+		{"only special chars", "-._@", false},
+		{"valid long", "a1234567890_b.c-d@e", true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.expected, ValidateUsername(tt.input))
+		})
+	}
+}
+
+func TestValidateClientID(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected bool
+	}{
+		{"valid simple", "client123", true},
+		{"valid with dot", "client.id", true},
+		{"valid with underscore", "client_id", true},
+		{"valid with hyphen", "client-id", true},
+		{"valid with all", "client.id-123_abc", true},
+		{"contains space", "client id", false},
+		{"contains at", "client@id", false},
+		{"empty", "", false},
+		{"only special chars", "-._", true},
+		{"invalid char", "client!id", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.expected, ValidateClientID(tt.input))
+		})
+	}
+}