fix(lists): propagate checkbox state to ancestor list items on toggle

Toggling/cycling/rejecting a nested checkbox now recomputes each
ancestor's progress marker (vimwiki's listsyms_propagate). Mirrors
vimwiki's averaging — rejected items count as 100% unless every child
is rejected, in which case the parent itself becomes rejected. Walks
up while each ancestor has its own checkbox.

Also tightens find_checkbox_span to scan only the marker line, since a
parent item's span covers its nested sublist and was matching child
markers as if they belonged to the parent.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/nuwiki-lsp/tests/commands_checkboxes.rs

@@ -60,7 +60,7 @@ fn reject_state_toggles_dash_marker() {
 fn toggle_empty_checkbox_to_done() {
     let src = "- [ ] task\n";
     let doc = parse(src);
-    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 4, true, ops::toggle_state)
+    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 4, true, ops::toggle_state, true)
         .expect("toggle edit");
     let te = one_text_edit(edit);
     assert_eq!(te.new_text, "[X]");
@@ -72,7 +72,7 @@ fn toggle_empty_checkbox_to_done() {
 fn cycle_advances_partial_states() {
     let src = "- [.] half\n";
     let doc = parse(src);
-    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 0, true, ops::cycle_state)
+    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 0, true, ops::cycle_state, true)
         .expect("cycle edit");
     let te = one_text_edit(edit);
     assert_eq!(te.new_text, "[o]");
@@ -82,7 +82,7 @@ fn cycle_advances_partial_states() {
 fn reject_replaces_empty_with_dash() {
     let src = "* [ ] thing\n";
     let doc = parse(src);
-    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 0, true, ops::reject_state)
+    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 0, true, ops::reject_state, true)
         .expect("reject edit");
     let te = one_text_edit(edit);
     assert_eq!(te.new_text, "[-]");
@@ -93,7 +93,7 @@ fn checkbox_edit_returns_none_on_plain_list_item() {
     // No `[…]` at all → no edit.
     let src = "- plain item\n";
     let doc = parse(src);
-    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 0, true, ops::toggle_state);
+    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 0, true, ops::toggle_state, true);
     assert!(edit.is_none());
 }
 
@@ -101,7 +101,7 @@ fn checkbox_edit_returns_none_on_plain_list_item() {
 fn checkbox_edit_returns_none_off_list() {
     let src = "just a paragraph\n";
     let doc = parse(src);
-    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 0, true, ops::toggle_state);
+    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 0, true, ops::toggle_state, true);
     assert!(edit.is_none());
 }
 
@@ -110,7 +110,7 @@ fn checkbox_edit_finds_item_in_sublist() {
     let src = "- top\n  - [ ] nested\n";
     let doc = parse(src);
     // Cursor on line 1, the nested item.
-    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 1, 5, true, ops::toggle_state)
+    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 1, 5, true, ops::toggle_state, true)
         .expect("edit on nested item");
     let te = one_text_edit(edit);
     assert_eq!(te.new_text, "[X]");
@@ -123,7 +123,189 @@ fn checkbox_edit_finds_item_in_sublist() {
 fn checkbox_edit_uses_changes_map_not_document_changes() {
     let src = "- [ ] task\n";
     let doc = parse(src);
-    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 4, true, ops::toggle_state).unwrap();
+    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 4, true, ops::toggle_state, true).unwrap();
     assert!(doc_changes_for(edit.clone()).is_none());
     assert!(edit.changes.is_some());
 }
+
+// ===== parent propagation (vimwiki listsyms_propagate) =====
+
+/// Collect the (line, new_text) pairs for every TextEdit in the result,
+/// sorted by line. Lets propagation tests assert the parent edit
+/// without caring about edit ordering.
+fn edits_by_line(edit: tower_lsp::lsp_types::WorkspaceEdit) -> Vec<(u32, String)> {
+    let changes = edit.changes.expect("expected changes map");
+    let (_, edits) = changes.into_iter().next().expect("at least one uri");
+    let mut pairs: Vec<(u32, String)> = edits
+        .into_iter()
+        .map(|e| (e.range.start.line, e.new_text))
+        .collect();
+    pairs.sort_by_key(|(line, _)| *line);
+    pairs
+}
+
+#[test]
+fn propagate_one_of_four_done_marks_parent_quarter() {
+    // Toggle the first child of a 4-child parent. Parent should land at
+    // [.] (Quarter, 25%).
+    let src = "\
+- [ ] root
+  - [ ] sub1
+  - [ ] sub2
+  - [ ] sub3
+  - [ ] sub4
+";
+    let doc = parse(src);
+    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 1, 6, true, ops::toggle_state, true)
+        .expect("toggle edit");
+    let pairs = edits_by_line(edit);
+    assert_eq!(pairs, vec![(0, "[.]".into()), (1, "[X]".into())]);
+}
+
+#[test]
+fn propagate_two_of_four_done_marks_parent_half() {
+    // sub1 is already done; toggling sub2 → done leaves rate=50% → [o].
+    let src = "\
+- [ ] root
+  - [X] sub1
+  - [ ] sub2
+  - [ ] sub3
+  - [ ] sub4
+";
+    let doc = parse(src);
+    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 2, 6, true, ops::toggle_state, true)
+        .expect("toggle edit");
+    let pairs = edits_by_line(edit);
+    assert_eq!(pairs, vec![(0, "[o]".into()), (2, "[X]".into())]);
+}
+
+#[test]
+fn propagate_three_of_four_done_marks_parent_three_quarters() {
+    let src = "\
+- [ ] root
+  - [X] sub1
+  - [X] sub2
+  - [ ] sub3
+  - [ ] sub4
+";
+    let doc = parse(src);
+    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 3, 6, true, ops::toggle_state, true)
+        .expect("toggle edit");
+    let pairs = edits_by_line(edit);
+    assert_eq!(pairs, vec![(0, "[O]".into()), (3, "[X]".into())]);
+}
+
+#[test]
+fn propagate_all_done_marks_parent_done() {
+    let src = "\
+- [ ] root
+  - [X] sub1
+  - [X] sub2
+  - [X] sub3
+  - [ ] sub4
+";
+    let doc = parse(src);
+    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 4, 6, true, ops::toggle_state, true)
+        .expect("toggle edit");
+    let pairs = edits_by_line(edit);
+    assert_eq!(pairs, vec![(0, "[X]".into()), (4, "[X]".into())]);
+}
+
+#[test]
+fn propagate_untoggle_drops_parent_back() {
+    // Untoggling the only completed child should put parent back to [ ].
+    let src = "\
+- [.] root
+  - [X] sub1
+  - [ ] sub2
+  - [ ] sub3
+  - [ ] sub4
+";
+    let doc = parse(src);
+    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 1, 6, true, ops::toggle_state, true)
+        .expect("toggle edit");
+    let pairs = edits_by_line(edit);
+    assert_eq!(pairs, vec![(0, "[ ]".into()), (1, "[ ]".into())]);
+}
+
+#[test]
+fn propagate_disabled_only_emits_leaf_edit() {
+    let src = "\
+- [ ] root
+  - [ ] sub1
+  - [ ] sub2
+  - [ ] sub3
+  - [ ] sub4
+";
+    let doc = parse(src);
+    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 1, 6, true, ops::toggle_state, false)
+        .expect("toggle edit");
+    let pairs = edits_by_line(edit);
+    assert_eq!(pairs, vec![(1, "[X]".into())]);
+}
+
+#[test]
+fn propagate_skips_parent_without_checkbox() {
+    // Parent has no `[…]`, so propagation has nothing to update.
+    let src = "\
+- root
+  - [ ] sub1
+  - [ ] sub2
+";
+    let doc = parse(src);
+    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 1, 6, true, ops::toggle_state, true)
+        .expect("toggle edit");
+    let pairs = edits_by_line(edit);
+    assert_eq!(pairs, vec![(1, "[X]".into())]);
+}
+
+#[test]
+fn propagate_walks_multiple_levels() {
+    // Toggle the deepest leaf: grandparent has 1 child (parent), parent
+    // has 2 children. Sub1 done → parent half → grandparent half.
+    let src = "\
+- [ ] grand
+  - [ ] parent
+    - [ ] sub1
+    - [ ] sub2
+";
+    let doc = parse(src);
+    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 2, 8, true, ops::toggle_state, true)
+        .expect("toggle edit");
+    let pairs = edits_by_line(edit);
+    assert_eq!(
+        pairs,
+        vec![(0, "[o]".into()), (1, "[o]".into()), (2, "[X]".into())]
+    );
+}
+
+#[test]
+fn propagate_all_rejected_marks_parent_rejected() {
+    // Every counted child is rejected → parent becomes [-].
+    let src = "\
+- [ ] root
+  - [-] sub1
+  - [ ] sub2
+";
+    let doc = parse(src);
+    // Reject sub2 so both children are rejected.
+    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 2, 6, true, ops::reject_state, true)
+        .expect("reject edit");
+    let pairs = edits_by_line(edit);
+    assert_eq!(pairs, vec![(0, "[-]".into()), (2, "[-]".into())]);
+}
+
+#[test]
+fn propagate_rejected_sibling_counts_as_done_for_average() {
+    // sub1 rejected, sub2 toggled to done → both "complete" → parent [X].
+    let src = "\
+- [ ] root
+  - [-] sub1
+  - [ ] sub2
+";
+    let doc = parse(src);
+    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 2, 6, true, ops::toggle_state, true)
+        .expect("toggle edit");
+    let pairs = edits_by_line(edit);
+    assert_eq!(pairs, vec![(0, "[X]".into()), (2, "[X]".into())]);
+}