Improve suggestion in case a bare URL is surrounded by brackets

Author: GuillaumeGomez

src/librustdoc/passes/lint/bare_urls.rs

@@ -17,33 +17,43 @@ use crate::core::DocContext;
 use crate::html::markdown::main_body_opts;
 
 pub(super) fn visit_item(cx: &DocContext<'_>, item: &Item, hir_id: HirId, dox: &str) {
-    let report_diag = |cx: &DocContext<'_>, msg: &'static str, range: Range<usize>| {
-        let maybe_sp = source_span_for_markdown_range(cx.tcx, dox, &range, &item.attrs.doc_strings)
-            .map(|(sp, _)| sp);
-        let sp = maybe_sp.unwrap_or_else(|| item.attr_span(cx.tcx));
-        cx.tcx.node_span_lint(crate::lint::BARE_URLS, hir_id, sp, |lint| {
-            lint.primary_message(msg)
-                .note("bare URLs are not automatically turned into clickable links");
-            // The fallback of using the attribute span is suitable for
-            // highlighting where the error is, but not for placing the < and >
-            if let Some(sp) = maybe_sp {
-                lint.multipart_suggestion(
-                    "use an automatic link instead",
-                    vec![
-                        (sp.shrink_to_lo(), "<".to_string()),
-                        (sp.shrink_to_hi(), ">".to_string()),
-                    ],
-                    Applicability::MachineApplicable,
-                );
-            }
-        });
-    };
+    let report_diag =
+        |cx: &DocContext<'_>, msg: &'static str, range: Range<usize>, no_brackets: Option<&str>| {
+            let maybe_sp =
+                source_span_for_markdown_range(cx.tcx, dox, &range, &item.attrs.doc_strings)
+                    .map(|(sp, _)| sp);
+            let sp = maybe_sp.unwrap_or_else(|| item.attr_span(cx.tcx));
+            cx.tcx.node_span_lint(crate::lint::BARE_URLS, hir_id, sp, |lint| {
+                lint.primary_message(msg)
+                    .note("bare URLs are not automatically turned into clickable links");
+                // The fallback of using the attribute span is suitable for
+                // highlighting where the error is, but not for placing the < and >
+                if let Some(sp) = maybe_sp {
+                    if let Some(no_brackets) = no_brackets {
+                        lint.multipart_suggestion(
+                            "use an automatic link instead",
+                            vec![(sp, format!("<{no_brackets}>"))],
+                            Applicability::MachineApplicable,
+                        );
+                    } else {
+                        lint.multipart_suggestion(
+                            "use an automatic link instead",
+                            vec![
+                                (sp.shrink_to_lo(), "<".to_string()),
+                                (sp.shrink_to_hi(), ">".to_string()),
+                            ],
+                            Applicability::MachineApplicable,
+                        );
+                    }
+                }
+            });
+        };
 
     let mut p = Parser::new_ext(dox, main_body_opts()).into_offset_iter();
 
     while let Some((event, range)) = p.next() {
         match event {
-            Event::Text(s) => find_raw_urls(cx, &s, range, &report_diag),
+            Event::Text(s) => find_raw_urls(cx, dox, &s, range, &report_diag),
             // We don't want to check the text inside code blocks or links.
             Event::Start(tag @ (Tag::CodeBlock(_) | Tag::Link { .. })) => {
                 for (event, _) in p.by_ref() {
@@ -67,25 +77,41 @@ static URL_REGEX: LazyLock<Regex> = LazyLock::new(|| {
         r"https?://",                          // url scheme
         r"([-a-zA-Z0-9@:%._\+~#=]{2,256}\.)+", // one or more subdomains
         r"[a-zA-Z]{2,63}",                     // root domain
-        r"\b([-a-zA-Z0-9@:%_\+.~#?&/=]*)"      // optional query or url fragments
+        r"\b([-a-zA-Z0-9@:%_\+.~#?&/=]*)",     // optional query or url fragments
     ))
     .expect("failed to build regex")
 });
 
 fn find_raw_urls(
     cx: &DocContext<'_>,
+    whole_text: &str,
     text: &str,
     range: Range<usize>,
-    f: &impl Fn(&DocContext<'_>, &'static str, Range<usize>),
+    f: &impl Fn(&DocContext<'_>, &'static str, Range<usize>, Option<&str>),
 ) {
     trace!("looking for raw urls in {text}");
     // For now, we only check "full" URLs (meaning, starting with "http://" or "https://").
     for match_ in URL_REGEX.find_iter(text) {
         let url_range = match_.range();
+        let mut no_brackets = None;
+        let mut extra_range = 0;
+        // If the whole text is contained inside `[]`, then we need to replace the brackets and
+        // not just add `<>`.
+        if whole_text[..range.start + url_range.start].ends_with('[')
+            && range.start + url_range.end <= whole_text.len()
+            && whole_text[range.start + url_range.end..].starts_with(']')
+        {
+            extra_range = 1;
+            no_brackets = Some(match_.as_str());
+        }
         f(
             cx,
             "this URL is not a hyperlink",
-            Range { start: range.start + url_range.start, end: range.start + url_range.end },
+            Range {
+                start: range.start + url_range.start - extra_range,
+                end: range.start + url_range.end + extra_range,
+            },
+            no_brackets,
         );
     }
 }