feat: add import support and unit tests for provider resources

terraform/provider/internal/resources/import_helpers_test.go

@@ -0,0 +1,23 @@
+package resources
+
+import "testing"
+
+func TestParseImportID(t *testing.T) {
+	namespace, name, err := parseImportID("default/my-resource")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if namespace != "default" || name != "my-resource" {
+		t.Fatalf("unexpected parsed values: namespace=%q name=%q", namespace, name)
+	}
+}
+
+func TestParseImportIDInvalid(t *testing.T) {
+	invalidIDs := []string{"", "default", "default/", "/name", "a/b/c"}
+	for _, importID := range invalidIDs {
+		_, _, err := parseImportID(importID)
+		if err == nil {
+			t.Fatalf("expected error for import id %q", importID)
+		}
+	}
+}