documents: alerts read their marker from parsed text; GFM's filtered tags show as text; block elements close what opened inside them; a TOC press relocates its heading after a write-back or a pending read and acts on press

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/documents/document/place.rs

@@ -1,6 +1,6 @@
 use gpui::{App, Context, Focusable as _, ListOffset, ScrollStrategy, Window, px};
 
-use super::{MarkdownDocument, Placement};
+use super::{DocumentHeading, MarkdownDocument, Placement};
 use crate::documents::{MarkdownMode, modes::joint};
 
 /// Line and column, from zero, of byte `at` in `text`.
@@ -189,13 +189,27 @@ impl MarkdownDocument {
             .saturating_sub(1)
     }
 
-    /// Reveals the line holding byte `at` of the text.
+    /// Reveals the pressed heading, found again in the text.
     pub(super) fn reveal_at(&mut self, at: usize, window: &mut Window, cx: &mut Context<Self>) {
-        let editor = self.editor.read(cx);
-        if at > editor.text().len() {
-            return log::error!("markdown document: a heading past the text");
+        let headings = &self.parsed.headings;
+        let Some(ix) = headings.iter().position(|heading| heading.at == at) else {
+            return log::warn!("markdown document: a heading read away");
+        };
+        let pressed = headings[ix].clone();
+        let same = |heading: &&DocumentHeading| {
+            (heading.depth, &heading.title) == (pressed.depth, &pressed.title)
+        };
+        let nth = headings[..ix].iter().filter(same).count();
+        if self.commit(cx).is_some() || !self.read_now(cx) {
+            self.reparse(true, cx);
         }
-        let line = editor.buffer.line_of(at);
+        if !self.read_now(cx) {
+            return log::warn!("markdown document: a heading pressed while the text is read again");
+        }
+        let Some(found) = self.parsed.headings.iter().filter(same).nth(nth) else {
+            return log::warn!("markdown document: the pressed heading changed as one wrote");
+        };
+        let line = self.editor.read(cx).buffer.line_of(found.at);
         self.reveal(line, window, cx);
     }
 

src/documents/document/tests/toc.rs

@@ -1,6 +1,6 @@
 use gpui::{Modifiers, MouseButton, TestAppContext, VisualTestContext, point, px};
 
-use super::{MarkdownMode, open};
+use super::{MarkdownMode, frames, open, type_in};
 
 const LISTED: &str = "[toc]\n\n# A\n\ntext\n\n## B\n";
 
@@ -34,3 +34,35 @@ fn visual_reveals_on_a_secondary_press_and_edits_on_a_plain_one(cx: &mut TestApp
     press_entry(0, Modifiers::none(), cx);
     assert!(document.read_with(cx, |document, _| document.open.is_some()));
 }
+
+#[gpui::test]
+fn a_press_after_an_earlier_block_grew_finds_the_heading(cx: &mut TestAppContext) {
+    let text = "before\n\n[toc]\n\n# A\n\ntext\n\n## B\n";
+    let (document, cx) = open(text, MarkdownMode::Visual, cx);
+    type_in(&document, Some(0), Some("before\nextra\nextra"), cx);
+    frames(cx);
+    press_entry(1, Modifiers::secondary_key(), cx);
+    frames(cx);
+    assert_eq!(
+        document.read_with(cx, |document, cx| document.caret(cx)),
+        (10, 0)
+    );
+}
+
+#[gpui::test]
+fn a_press_while_the_text_waits_to_be_read_finds_the_heading(cx: &mut TestAppContext) {
+    let (document, cx) = open(LISTED, MarkdownMode::Split, cx);
+    document.update(cx, |document, cx| {
+        document.editor.update(cx, |editor, cx| {
+            editor.edit([(0..0, "inserted\n".repeat(20))], cx);
+        });
+    });
+    cx.run_until_parked();
+    assert!(!document.read_with(cx, |document, cx| document.read_now(cx)));
+    press_entry(1, Modifiers::none(), cx);
+    frames(cx);
+    assert_eq!(
+        document.read_with(cx, |document, cx| document.caret(cx)),
+        (26, 0)
+    );
+}