From 46e21fccc76e07f38529e87fd5d4647f9c979e12 Mon Sep 17 00:00:00 2001
From: Zixuan Chen <remch183@outlook.com>
Date: Sat, 7 Sep 2024 16:49:28 +0800
Subject: [PATCH] fix: two tree move (inside the same parent) issues (#450)

* fix: two tree move (inside the same parent) issues

* chore: add release note
---
 .changeset/lemon-maps-smash.md           |  6 ++++++
 crates/loro-internal/src/handler/tree.rs |  2 +-
 crates/loro/src/lib.rs                   |  4 +---
 crates/loro/tests/loro_rust_test.rs      | 19 +++++++++++++++++++
 loro-js/tests/tree.test.ts               | 12 +++++++++++-
 5 files changed, 38 insertions(+), 5 deletions(-)
 create mode 100644 .changeset/lemon-maps-smash.md

diff --git a/.changeset/lemon-maps-smash.md b/.changeset/lemon-maps-smash.md
new file mode 100644
index 00000000..dec550dc
--- /dev/null
+++ b/.changeset/lemon-maps-smash.md
@@ -0,0 +1,6 @@
+---
+"loro-crdt": patch
+"loro-wasm": patch
+---
+
+Fix tree move issues
diff --git a/crates/loro-internal/src/handler/tree.rs b/crates/loro-internal/src/handler/tree.rs
index 7b9e2718..539b39ec 100644
--- a/crates/loro-internal/src/handler/tree.rs
+++ b/crates/loro-internal/src/handler/tree.rs
@@ -518,7 +518,7 @@ impl TreeHandler {
             .ok_or(LoroTreeError::TreeNodeNotExist(other))?;
         let mut index = self.get_index_by_tree_id(&other).unwrap();
         if self.is_parent(target, parent)
-            && index > 1
+            && index >= 1
             && self.get_index_by_tree_id(&target).unwrap() < index
         {
             index -= 1;
diff --git a/crates/loro/src/lib.rs b/crates/loro/src/lib.rs
index a985426b..a49040c4 100644
--- a/crates/loro/src/lib.rs
+++ b/crates/loro/src/lib.rs
@@ -1322,9 +1322,7 @@ impl LoroTree {
     /// tree.mov(root2, root).unwrap();
     /// ```
     pub fn mov<T: Into<Option<TreeID>>>(&self, target: TreeID, parent: T) -> LoroResult<()> {
-        let parent = parent.into();
-        let index = self.children_num(parent).unwrap_or(0);
-        self.handler.move_to(target, parent, index)
+        self.handler.mov(target, parent)
     }
 
     /// Move the `target` node to be a child of the `parent` node at the given index.
diff --git a/crates/loro/tests/loro_rust_test.rs b/crates/loro/tests/loro_rust_test.rs
index a8706b8e..d9b36a46 100644
--- a/crates/loro/tests/loro_rust_test.rs
+++ b/crates/loro/tests/loro_rust_test.rs
@@ -871,3 +871,22 @@ fn len_and_is_empty_inconsistency() {
     assert_eq!(map.len(), 0);
     assert!(map.is_empty());
 }
+
+#[test]
+fn test_tree_move() {
+    let doc = LoroDoc::new();
+    let tree = doc.get_tree("tree");
+    let root1 = tree.create(None).unwrap();
+    let node1 = tree.create(root1).unwrap();
+    let node2 = tree.create(root1).unwrap();
+    assert_eq!(tree.children(Some(root1)).unwrap(), vec![node1, node2]);
+    tree.mov_before(node2, node1).unwrap();
+    assert_eq!(tree.children(Some(root1)).unwrap(), vec![node2, node1]);
+    tree.mov_before(node2, node1).unwrap();
+    assert_eq!(tree.children(Some(root1)).unwrap(), vec![node2, node1]);
+
+    tree.mov_after(node2, node1).unwrap();
+    assert_eq!(tree.children(Some(root1)).unwrap(), vec![node1, node2]);
+    tree.mov_after(node2, node1).unwrap();
+    assert_eq!(tree.children(Some(root1)).unwrap(), vec![node1, node2]);
+}
diff --git a/loro-js/tests/tree.test.ts b/loro-js/tests/tree.test.ts
index d6a2d07f..b34f482d 100644
--- a/loro-js/tests/tree.test.ts
+++ b/loro-js/tests/tree.test.ts
@@ -182,6 +182,16 @@ describe("loro tree node", ()=>{
     });
 });
 
+describe("LoroTree", () => {
+  it ("move", () => {
+    const loro = new Loro();
+    const tree = loro.getTree("root");
+    const root = tree.createNode();
+    const child = tree.createNode(root.id);
+    tree.move(child.id, root.id);
+  })
+})
+
 function one_ms(): Promise<void> {
   return new Promise((resolve) => setTimeout(resolve, 1));
-}
\ No newline at end of file
+}