feat: declare a Mews page's feed, keep its prolog, and lift link-only list items

gemtext/src/lib.rs

@@ -113,7 +113,7 @@ impl Writer {
                     // number in the text to keep the sequence readable.
                     if *ordered {
                         self.line(&format!("* {}. {text}", start + index as u64));
-                    } else {
+                    } else if !is_only_links_item(item) {
                         self.line(&format!("* {text}"));
                     }
                     for block in item {
@@ -201,6 +201,16 @@ impl Writer {
     }
 }
 
+/// Whether a list item holds links and nothing else worth printing, in which
+/// case the `=>` lines are the whole item and a marker line above them would
+/// list every entry twice -- the same reading [`is_only_links`] gives a
+/// paragraph. Markup other than one paragraph keeps its marker, since the
+/// shape is then doing something a link catalogue alone would not carry; so
+/// does an ordered item, whose number would go with it.
+fn is_only_links_item(item: &[Block]) -> bool {
+    matches!(item, [Block::Paragraph(inline)] if is_only_links(inline))
+}
+
 /// Whether a paragraph holds links and nothing else worth printing.
 fn is_only_links(inline: &[Inline]) -> bool {
     let mut saw_link = false;
@@ -295,8 +305,7 @@ mod tests_support {
     pub fn render(markdown: &str) -> String {
         let doc = parse::markdown(markdown).unwrap();
         let settings = PageSettings::default();
-        let ctx =
-            RenderCtx { url: "/x", title: "T", settings: &settings, width: None, mews_hosts: None };
+        let ctx = RenderCtx { url: "/x", title: "T", settings: &settings, width: None, mews: None };
         let out = Gemtext.render(&doc, &ctx).unwrap();
         String::from_utf8(out.body).unwrap()
     }
@@ -371,6 +380,19 @@ mod tests {
         assert_eq!(render("- see [x](/x)\n"), "* see x\n=> /x x\n");
     }
 
+    #[test]
+    fn a_list_of_bare_links_is_a_run_of_link_lines() {
+        // The shape a generator wants for a dated index: a real list, so the
+        // markup formats can give it <ul><li>, without gemtext printing both
+        // the marker line and the link line for every entry.
+        assert_eq!(render("- [a](/a)\n- [b](/b)\n"), "=> /a a\n=> /b b\n");
+    }
+
+    #[test]
+    fn an_ordered_list_of_bare_links_keeps_its_numbers() {
+        assert_eq!(render("1. [a](/a)\n"), "* 1. a\n=> /a a\n");
+    }
+
     #[test]
     fn code_blocks_become_fences_carrying_their_info_string() {
         assert_eq!(render("```rust\nlet x = 1;\n```\n"), "```rust\nlet x = 1;\n```\n");
@@ -399,8 +421,7 @@ mod tests {
         // Pagination is a WML concern; a Gemini client scrolls one document.
         let doc = parse::markdown("a\n\nb\n").unwrap();
         let settings = PageSettings::default();
-        let ctx =
-            RenderCtx { url: "/x", title: "T", settings: &settings, width: None, mews_hosts: None };
+        let ctx = RenderCtx { url: "/x", title: "T", settings: &settings, width: None, mews: None };
         let plain = String::from_utf8(Gemtext.render(&doc, &ctx).unwrap().body).unwrap();
         assert_eq!(plain, "a\n\nb\n");
     }