Fix programmatic cursor position updates

Author: gerardp

Sources/CodeEditSourceEditor/SourceEditor/SourceEditor.swift

@@ -159,8 +159,8 @@ public struct SourceEditor: NSViewControllerRepresentable {
         return
     }
 
-    private func updateControllerWithState(_ state: SourceEditorState, controller: TextViewController) {
-        if let cursorPositions = state.cursorPositions, cursorPositions != state.cursorPositions {
+    func updateControllerWithState(_ state: SourceEditorState, controller: TextViewController) {
+        if let cursorPositions = state.cursorPositions, cursorPositions != controller.cursorPositions {
             controller.setCursorPositions(cursorPositions)
         }
 

Tests/CodeEditSourceEditorTests/Controller/TextViewControllerTests.swift

@@ -432,6 +432,24 @@ final class TextViewControllerTests: XCTestCase {
         XCTAssertEqual(controller.cursorPositions[1].start.column, 1)
     }
 
+    func test_sourceEditorUpdatesCursorPositionsFromState() {
+        controller.setText("1\n2\n")
+        controller.setCursorPositions([CursorPosition(line: 1, column: 1)])
+        let editor = SourceEditor(
+            .constant(""),
+            language: .default,
+            configuration: Mock.config(),
+            state: .constant(SourceEditorState())
+        )
+
+        editor.updateControllerWithState(
+            SourceEditorState(cursorPositions: [CursorPosition(line: 2, column: 1)]),
+            controller: controller
+        )
+
+        XCTAssertEqual(controller.cursorPositions.first?.start, CursorPosition.Position(line: 2, column: 1))
+    }
+
     // MARK: - TreeSitterClient
 
     func test_treeSitterSetUp() {