From 06c37f89b017734bd9b2671ffdcfe14a03125e4b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=9B=B7=E7=94=B5=E8=8A=BD=E8=A1=A3?=
 <zhangyanghaha0407@outlook.com>
Date: Fri, 8 May 2026 05:07:19 -0400
Subject: [PATCH] Track tab opener relationships

---
 crates/ely_browser_core/src/state/tabs.rs |  1 +
 crates/ely_browser_core/tests/tabs.rs     | 34 +++++++++++++++++++++++
 crates/ely_domain/src/tab.rs              | 13 +++++++++
 3 files changed, 48 insertions(+)

diff --git a/crates/ely_browser_core/src/state/tabs.rs b/crates/ely_browser_core/src/state/tabs.rs
index 096e73f..dde3720 100644
--- a/crates/ely_browser_core/src/state/tabs.rs
+++ b/crates/ely_browser_core/src/state/tabs.rs
@@ -322,6 +322,7 @@ impl BrowserCore {
 
     fn build_tab(&self, url: UrlText) -> BrowserTab {
         self.build_tab_for(self.active_space_id.clone(), self.active_profile_id.clone(), url)
+            .with_parent_tab_id(self.active_tab_id.clone())
     }
 
     pub(super) fn nearest_tab_in_space(
diff --git a/crates/ely_browser_core/tests/tabs.rs b/crates/ely_browser_core/tests/tabs.rs
index 9a1174d..31fc06f 100644
--- a/crates/ely_browser_core/tests/tabs.rs
+++ b/crates/ely_browser_core/tests/tabs.rs
@@ -22,6 +22,40 @@ fn opens_new_tab_below_active_tab() -> Result<(), Box<dyn Error>> {
     Ok(())
 }
 
+#[test]
+fn opened_tabs_record_active_tab_as_parent() -> Result<(), Box<dyn Error>> {
+    let mut core = BrowserCore::new(InitialBrowserConfig::ely_defaults()?)?;
+    let first_tab_id = core.active_tab()?.id().clone();
+
+    let second_tab_id = core.open_tab(UrlText::parse("https://example.com")?);
+    let snapshot = core.snapshot()?;
+
+    let opened_tab = snapshot
+        .tabs
+        .iter()
+        .find(|tab| tab.id() == &second_tab_id)
+        .ok_or(CoreError::MissingActiveTab)?;
+    assert_eq!(opened_tab.parent_tab_id(), Some(&first_tab_id));
+    Ok(())
+}
+
+#[test]
+fn replacement_tabs_have_no_parent_tab() -> Result<(), Box<dyn Error>> {
+    let mut core = BrowserCore::new(InitialBrowserConfig::ely_defaults()?)?;
+    let active_tab_id = core.active_tab()?.id().clone();
+
+    let replacement_tab_id = core.close_tab(&active_tab_id)?;
+    let snapshot = core.snapshot()?;
+
+    let replacement_tab = snapshot
+        .tabs
+        .iter()
+        .find(|tab| tab.id() == &replacement_tab_id)
+        .ok_or(CoreError::MissingActiveTab)?;
+    assert_eq!(replacement_tab.parent_tab_id(), None);
+    Ok(())
+}
+
 #[test]
 fn closes_active_tab_and_selects_next_neighbor() -> Result<(), Box<dyn Error>> {
     let mut core = BrowserCore::new(InitialBrowserConfig::ely_defaults()?)?;
diff --git a/crates/ely_domain/src/tab.rs b/crates/ely_domain/src/tab.rs
index 04223b8..3621770 100644
--- a/crates/ely_domain/src/tab.rs
+++ b/crates/ely_domain/src/tab.rs
@@ -26,6 +26,7 @@ pub struct BrowserTab {
     profile_id: ProfileId,
     title: String,
     url: UrlText,
+    parent_tab_id: Option<TabId>,
     state: TabState,
     flags: TabFlags,
     split_id: Option<SplitId>,
@@ -49,6 +50,7 @@ impl BrowserTab {
             profile_id,
             title: title.into(),
             url,
+            parent_tab_id: None,
             state: TabState::Ready,
             flags: TabFlags::default(),
             split_id: None,
@@ -57,6 +59,12 @@ impl BrowserTab {
         }
     }
 
+    #[must_use]
+    pub fn with_parent_tab_id(mut self, parent_tab_id: TabId) -> Self {
+        self.parent_tab_id = Some(parent_tab_id);
+        self
+    }
+
     #[must_use]
     pub fn id(&self) -> &TabId {
         &self.id
@@ -82,6 +90,11 @@ impl BrowserTab {
         &self.url
     }
 
+    #[must_use]
+    pub fn parent_tab_id(&self) -> Option<&TabId> {
+        self.parent_tab_id.as_ref()
+    }
+
     #[must_use]
     pub fn display_url(&self) -> String {
         self.url.display_url()