From 40e9d6c28148709706ea036b3cadc69e56952410 Mon Sep 17 00:00:00 2001
From: Jeremy Rose <japthorp@slack-corp.com>
Date: Thu, 21 Mar 2024 15:49:23 -0700
Subject: [PATCH] add doc.get_last_local_change

---
 rust/src/lib.rs              | 11 +++++++++++
 src/automerge/_automerge.pyi |  1 +
 tests/test_basic.py          | 28 ++++++++++++++++++++++++++++
 tests/test_changes.py        | 10 ++++++----
 4 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/rust/src/lib.rs b/rust/src/lib.rs
index a4af4e1..4d71a5a 100644
--- a/rust/src/lib.rs
+++ b/rust/src/lib.rs
@@ -366,6 +366,17 @@ impl Document {
         Ok(inner.get_heads())
     }
 
+    fn get_last_local_change(&self) -> PyResult<Option<PyChange>> {
+        let inner = self
+            .inner
+            .read()
+            .map_err(|e| PyException::new_err(e.to_string()))?;
+        Ok(inner
+            .doc
+            .get_last_local_change()
+            .map(|c| PyChange(c.to_owned())))
+    }
+
     fn object_type(&self, obj_id: PyObjId) -> PyResult<PyObjType> {
         let inner = self
             .inner
diff --git a/src/automerge/_automerge.pyi b/src/automerge/_automerge.pyi
index 9342a02..a3a31d5 100644
--- a/src/automerge/_automerge.pyi
+++ b/src/automerge/_automerge.pyi
@@ -21,6 +21,7 @@ class Document:
     def receive_sync_message(self, state: SyncState, msg: Message) -> None: ...
 
     def get_heads(self) -> list[bytes]: ...
+    def get_last_local_change(self) -> Optional[Change]: ...
     def object_type(self, obj_id: bytes) -> ObjType: ...
     def get_changes(self, have_deps: list[bytes]) -> list[Change]: ...
     def get(self, obj_id: bytes, prop: str | int, heads: Optional[list[bytes]] = None) -> Optional[tuple[Value, bytes]]: ...
diff --git a/tests/test_basic.py b/tests/test_basic.py
index 1914d82..136d8d2 100644
--- a/tests/test_basic.py
+++ b/tests/test_basic.py
@@ -73,3 +73,31 @@ def test_diff() -> None:
     patch = doc.diff([], doc.get_heads())
     assert len(patch) == 4
 
+def test_text_heads() -> None:
+    doc1 = Document(actor_id=b'A')
+
+    with doc1.transaction() as tx:
+        text_id = tx.put_object(ROOT, "text", ObjType.Text)
+        tx.insert(text_id, 0, ScalarType.Str, "h")
+
+    doc2 = doc1.fork()
+    doc2.set_actor(b'B')
+
+    with doc1.transaction() as tx:
+        tx.insert(text_id, 1, ScalarType.Str, "i")
+
+    with doc2.transaction() as tx:
+        tx.insert(text_id, 1, ScalarType.Str, "o")
+
+    a_change = doc1.get_last_local_change()
+    assert a_change is not None
+    b_change = doc2.get_last_local_change()
+    assert b_change is not None
+
+    doc1.merge(doc2)
+    heads = doc1.get_heads()
+    assert len(heads) == 2
+
+    assert doc1.text(text_id, [a_change.hash]) == 'hi'
+    assert doc1.text(text_id, [b_change.hash]) == 'ho'
+    assert doc1.text(text_id, [a_change.hash, b_change.hash]) == 'hoi'
diff --git a/tests/test_changes.py b/tests/test_changes.py
index a66c811..cd26209 100644
--- a/tests/test_changes.py
+++ b/tests/test_changes.py
@@ -1,6 +1,6 @@
 from datetime import datetime
-from typing import List
-from automerge.core import Document, ROOT, ScalarType, ObjType, extract
+from typing import List, Optional, Tuple
+from automerge.core import Document, ROOT, ScalarType, ObjType
 
 def test_get_changes() -> None:
     doc = Document()
@@ -68,6 +68,8 @@ def test_multi_author_changes() -> None:
     docB.merge(docA)
     docA.merge(docB)
 
+    assert len(docA.get_heads()) == 2
+
     # docA and docB are the same now, so pick one arbitrarily to read changes
     # out of for history linearization
     doc = docA
@@ -76,8 +78,8 @@ def test_multi_author_changes() -> None:
     assert changes[0].actor_id == b'A'
     assert changes[1].actor_id == b'B'
 
-    last_actor: bytes | None = None
-    snapshots: List[tuple[str, bytes | None]] = []
+    last_actor: Optional[bytes] = None
+    snapshots: List[Tuple[str, Optional[bytes]]] = []
     seen_heads: List[bytes] = []
     # Go through each of the changes, saving when the author changes.
     for change in changes: