improvements

src/tests/collab.rs

@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2026 Mateusz Gruszczyński @linuxiarz.pl
+ * Source-Available Code / Dual-Licensed.
+ *
+ * Free for non-commercial and evaluation use under terms of BSL/GPLv3.
+ * Commercial or production use requires a valid paid license.
+ * See LICENSE file in repository root for details.
+ */
+
+use super::*;
+
+fn operation(components: Vec<OperationComponent>) -> TextOperation {
+    TextOperation { components }
+}
+
+#[test]
+fn concurrent_insertions_have_stable_order() {
+    let left = operation(vec![
+        OperationComponent::Retain { count: 1 },
+        OperationComponent::Insert {
+            text: "X".into(),
+            owners: Vec::new(),
+        },
+        OperationComponent::Retain { count: 1 },
+    ]);
+    let right = operation(vec![
+        OperationComponent::Retain { count: 1 },
+        OperationComponent::Insert {
+            text: "Y".into(),
+            owners: Vec::new(),
+        },
+        OperationComponent::Retain { count: 1 },
+    ]);
+    let left_prime = transform_operation(&left, &right, true).unwrap();
+    let right_prime = transform_operation(&right, &left, false).unwrap();
+    let after_right = apply_operation_to_document("aYb", "[]", &left_prime, &[])
+        .unwrap()
+        .0;
+    let after_left = apply_operation_to_document("aXb", "[]", &right_prime, &[])
+        .unwrap()
+        .0;
+    assert_eq!(after_right, "aXYb");
+    assert_eq!(after_left, "aXYb");
+}
+
+#[test]
+fn utf16_offsets_support_emoji() {
+    let operation = operation(vec![
+        OperationComponent::Retain { count: 3 },
+        OperationComponent::Insert {
+            text: "x".into(),
+            owners: Vec::new(),
+        },
+        OperationComponent::Retain { count: 1 },
+    ]);
+    let result = apply_operation_to_document("A😀B", "[]", &operation, &[])
+        .unwrap()
+        .0;
+    assert_eq!(result, "A😀xB");
+}
+
+#[test]
+fn operation_from_edit_preserves_utf16_boundaries() {
+    let operation = operation_from_edit("A😀B", "A😀xB", "[]");
+    let result = apply_operation_to_document("A😀B", "[]", &operation, &[])
+        .unwrap()
+        .0;
+    assert_eq!(result, "A😀xB");
+}
+
+#[test]
+fn acknowledgements_survive_history_compaction() {
+    let mut document = CollaborativeDocument::new(String::new(), "[]".into(), 0);
+    for update_id in 1..=MAX_OPERATION_HISTORY as u64 + 8 {
+        let base_revision_id = document.revision_id;
+        let revision_id = base_revision_id + 1;
+        document.revision_id = revision_id;
+        document.record(AppliedOperation {
+            base_revision_id,
+            revision_id,
+            client_id: "client-123".into(),
+            update_id,
+            operation: TextOperation::default(),
+            owner_replacements: Vec::new(),
+        });
+    }
+    assert!(document.has_applied_update("client-123", 1));
+    assert_eq!(
+        document.acknowledged_updates("client-123"),
+        vec![MAX_OPERATION_HISTORY as u64 + 8]
+    );
+}