From a81cb0f21ef84d80cc40e31203ecd8e91d64d3dd Mon Sep 17 00:00:00 2001
From: AnhNgoo <110978888+AnhNgoo@users.noreply.github.com>
Date: Wed, 28 Oct 2026 10:22:31 +0700
Subject: [PATCH] test(engine): cover default workbook author and preservation

---
 crates/engine/tests/it/main.rs            |  1 +
 crates/engine/tests/it/workbook_author.rs | 50 +++++++++++++++++++++++
 2 files changed, 51 insertions(+)
 create mode 100644 crates/engine/tests/it/workbook_author.rs

diff --git a/crates/engine/tests/it/main.rs b/crates/engine/tests/it/main.rs
index 4c91e58ac..95220c68f 100644
--- a/crates/engine/tests/it/main.rs
+++ b/crates/engine/tests/it/main.rs
@@ -28,4 +28,5 @@ mod sparse_clear_invalidation;
 mod stored_list_shape;
 mod table_resize_overlap;
 mod table_total_row_last_row;
+mod workbook_author;
 mod wrap_row_height;
diff --git a/crates/engine/tests/it/workbook_author.rs b/crates/engine/tests/it/workbook_author.rs
new file mode 100644
index 000000000..7af8b5d68
--- /dev/null
+++ b/crates/engine/tests/it/workbook_author.rs
@@ -0,0 +1,50 @@
+//! Regression tests for the default author of newly created workbooks.
+
+use gridcraft_engine::{DocState, Session, Trust, io, model::Workbook};
+
+#[test]
+fn new_workbook_stamps_the_configured_user_name_at_creation() {
+    let mut session = Session::new();
+
+    session.prefs.user_name = "Ada Lovelace".into();
+    let first = session.new_workbook();
+
+    assert_eq!(session.documents()[first].wb.props.author, "Ada Lovelace");
+
+    // Changing the preference must not rewrite an existing workbook.
+    session.prefs.user_name = "Grace Hopper".into();
+
+    assert_eq!(session.documents()[first].wb.props.author, "Ada Lovelace");
+
+    // A new workbook uses the preference as it exists at creation.
+    let second = session.new_workbook();
+
+    assert_eq!(session.documents()[second].wb.props.author, "Grace Hopper");
+
+    assert_eq!(session.documents()[first].wb.props.author, "Ada Lovelace");
+}
+
+#[test]
+fn opening_and_resaving_preserves_the_existing_workbook_author() {
+    // An existing XLSX has its own author metadata.
+    let mut source = Workbook::new();
+    source.props.author = "Original Spreadsheet Author".into();
+
+    let bytes = io::save_bytes(&source, "source.xlsx").unwrap();
+    let (opened, _) = io::open_bytes("source.xlsx", &bytes).unwrap();
+
+    let mut session = Session::new();
+    session.prefs.user_name = "Current GridCraft User".into();
+
+    session.add_document(DocState::new(opened, None, "source".into(), Trust::FromFile));
+
+    // Opening an existing workbook must not replace its author.
+    assert_eq!(session.doc().unwrap().wb.props.author, "Original Spreadsheet Author");
+
+    // The original author must survive another XLSX save and reopen.
+    let saved = io::save_bytes(&session.doc().unwrap().wb, "saved.xlsx").unwrap();
+
+    let (reopened, _) = io::open_bytes("saved.xlsx", &saved).unwrap();
+
+    assert_eq!(reopened.props.author, "Original Spreadsheet Author");
+}