fix: broken text after receiving batched changes

crates/pgt_workspace/src/workspace/server/change.rs

@@ -65,6 +65,8 @@ impl Document {
 
         // when we recieive more than one change, we need to push back the changes based on the
         // total range of the previous ones. This is because the ranges are always related to the original state.
+        // BUT: only for the statement range changes, not for the text changes
+        // this is why we pass both varaints to apply_change
         let mut changes = Vec::new();
 
         let mut offset: i64 = 0;
@@ -86,9 +88,9 @@ impl Document {
                 change
             };
 
-            changes.extend(self.apply_change(adjusted_change));
+            changes.extend(self.apply_change(adjusted_change, change));
 
-            offset += change.change_size();
+            offset += adjusted_change.change_size();
         }
 
         self.version = change.version;
@@ -240,9 +242,17 @@ impl Document {
     }
 
     /// Applies a single change to the document and returns the affected statements
-    fn apply_change(&mut self, change: &ChangeParams) -> Vec<StatementChange> {
+    ///
+    /// * `change`: The range-adjusted change to use for statement changes
+    /// * `original_change`: The original change to use for text changes (yes, this is a bit confusing, and we might want to refactor this entire thing at some point.)
+    fn apply_change(
+        &mut self,
+        change: &ChangeParams,
+        original_change: &ChangeParams,
+    ) -> Vec<StatementChange> {
         // if range is none, we have a full change
         if change.range.is_none() {
+            // doesnt matter what change since range is null
             return self.apply_full_change(change);
         }
 
@@ -255,7 +265,7 @@ impl Document {
 
         let change_range = change.range.unwrap();
         let previous_content = self.content.clone();
-        let new_content = change.apply_to_text(&self.content);
+        let new_content = original_change.apply_to_text(&self.content);
 
         // we first need to determine the affected range and all affected statements, as well as
         // the index of the prev and the next statement, if any. The full affected range is the
@@ -1663,6 +1673,38 @@ KEY (\"organisation_id\") REFERENCES \"public\".\"organisation\"(\"id\") ON UPDA
         assert_document_integrity(&doc);
     }
 
+    #[test]
+    fn test_content_out_of_sync() {
+        let path = PgTPath::new("test.sql");
+        let initial_content = "select 1, 2, 2232231313393319 from unknown_users;\n";
+
+        let mut doc = Document::new(initial_content.to_string(), 0);
+
+        let change1 = ChangeFileParams {
+            path: path.clone(),
+            version: 1,
+            changes: vec![
+                ChangeParams {
+                    range: Some(TextRange::new(29.into(), 29.into())),
+                    text: "3".to_string(),
+                },
+                ChangeParams {
+                    range: Some(TextRange::new(30.into(), 30.into())),
+                    text: "1".to_string(),
+                },
+            ],
+        };
+
+        let _changes = doc.apply_file_change(&change1);
+
+        assert_eq!(
+            doc.content,
+            "select 1, 2, 223223131339331931 from unknown_users;\n"
+        );
+
+        assert_document_integrity(&doc);
+    }
+
     #[test]
     fn test_comments_only() {
         let path = PgTPath::new("test.sql");