fix(markdown): expand presentational tables into blocks

Honor presentation and none table roles with ASCII case-insensitive matching and HTML whitespace trimming. Preserve captions, cell content, and independent conversion of nested data tables.

Validation: cargo fmt --all; cargo clippy --workspace --all-targets --all-features -- -D warnings; cargo nextest run --no-fail-fast (18,162 passed, 13 skipped).

moli-html2md/README.md

@@ -64,13 +64,15 @@ and cell line breaks and paragraph boundaries use inline `<br>` tags. Attribute
 newlines are encoded or normalized so they cannot break a table row. GFM supplies
 missing trailing cells in short rows; the converter does not allocate a padded grid.
 
-Complex tables retain Turndown core's ordinary block expansion, in DOM order with
-blank lines between cells. This includes non-unit spans, multiple `thead` rows,
-rows wider than an explicit header, or cells containing nested tables, lists,
-headings, quotes or preformatted blocks. Inner simple tables can still produce
-GFM when their containing layout table is expanded. Roles, borders and CSS do
-not select another conversion path, so structurally simple layout tables also
-produce GFM. Complex layouts remain readable blocks instead of raw HTML tables.
+Tables with `role="presentation"` or `role="none"` retain ordinary block expansion,
+in DOM order with blank lines between cells, even when structurally simple. Role
+matching ignores ASCII case and surrounding HTML whitespace. The same fallback
+applies to complex tables: non-unit spans, multiple `thead` rows, rows wider than
+an explicit header, or cells containing nested tables, lists, headings, quotes
+or preformatted blocks. Inner simple tables can still produce GFM when their
+containing layout table is expanded. Other roles, borders and CSS do not select
+another conversion path. Complex layouts remain readable blocks instead of raw
+HTML tables.
 
 Supported output includes headings, paragraphs, emphasis, strikethrough, links,
 images, lists, blockquotes, hard breaks, and fenced code. Inline HTML is used when

moli-html2md/src/table.rs

@@ -26,6 +26,12 @@ impl<Id: Copy> Table<Id> {
         depth: usize,
         max_depth: usize,
     ) -> Option<Self> {
+        if dom.attribute(node, "role").is_some_and(|role| {
+            let role = role.trim_matches(is_space);
+            role.eq_ignore_ascii_case("presentation") || role.eq_ignore_ascii_case("none")
+        }) {
+            return None;
+        }
         let mut table = Self {
             captions: Vec::new(),
             cells: Vec::new().into_iter(),

moli-html2md/tests/tables.rs

@@ -55,14 +55,55 @@ fn wrapping_a_table_preserves_its_content() {
 }
 
 #[test]
-fn table_roles_do_not_change_conversion() {
+fn presentational_tables_expand_into_blocks() {
+    for role in ["presentation", "none", " PRESENTATION ", "\tNoNe\r\n"] {
+        for header in [
+            "",
+            "<tr><th>Name</th><th>Value</th></tr>",
+            "<thead><tr><td>Name</td><td>Value</td></tr></thead>",
+        ] {
+            let html = format!(
+                "<table role='{role}'><caption><strong>Title</strong></caption>{header}<tbody><tr><td><a href='/one'>one</a></td><td><code>two|three</code></td></tr></tbody><tfoot><tr><td>end</td></tr></tfoot></table>"
+            );
+            let heading = if header.is_empty() {
+                ""
+            } else {
+                "Name\n\nValue\n\n"
+            };
+            assert_eq!(
+                markdown(&html),
+                format!("**Title**\n\n{heading}[one](/one)\n\n`two|three`\n\nend"),
+                "{html}"
+            );
+        }
+    }
+}
+
+#[test]
+fn presentational_table_roles_do_not_propagate_to_nested_tables() {
+    for role in ["presentation", "none"] {
+        let inner =
+            "<table><tr><th>Name</th><th>Value</th></tr><tr><td>one</td><td>two</td></tr></table>";
+        let html = format!(
+            "<table role='{role}'><tr><td>before</td><td>{inner}</td><td>after</td></tr></table>"
+        );
+        assert_eq!(
+            markdown(&html),
+            "before\n\n| Name | Value |\n| --- | --- |\n| one | two |\n\nafter",
+            "{html}"
+        );
+    }
+}
+
+#[test]
+fn other_table_roles_do_not_change_conversion() {
     for role in [
         "",
-        "presentation",
-        "none",
-        " PRESENTATION ",
         "table",
         "grid",
+        "treegrid",
+        "presentationish",
+        "none-other",
     ] {
         let html = format!(
             "<table role='{role}'><tr><th>Name</th><th>Value</th></tr><tr><td>one</td><td>two</td></tr></table>"