Enhance suggestions for unresolved links with typos path

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -26,6 +26,7 @@ use rustc_resolve::rustdoc::{
 };
 use rustc_span::BytePos;
 use rustc_span::def_id::ModId;
+use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::symbol::{Ident, Symbol, sym};
 use rustc_structures::CrateType;
 use smallvec::{SmallVec, smallvec};
@@ -2008,6 +2009,56 @@ fn report_diagnostic(
     );
 }
 
+fn suggest_path_name_typo(
+    collector: &LinkCollector<'_, '_>,
+    diag: &mut Diag<'_, ()>,
+    span: Option<rustc_span::Span>,
+    link_range: &MarkdownLinkRange,
+    dox: &str,
+    module: ModId,
+    unresolved: &str,
+    has_partial_res: bool,
+    disambiguator: Option<Disambiguator>,
+) {
+    if unresolved.chars().count() <= 1 {
+        // There are too many false positives for single character typos.
+        return;
+    }
+
+    let tcx = collector.cx.tcx;
+    let lookup = Symbol::intern(unresolved);
+    let children = if let Some(local_module) = module.as_local() {
+        tcx.module_children_local(local_module.to_local_def_id())
+    } else {
+        tcx.module_children(module.to_def_id())
+    };
+    let candidates = children
+        .iter()
+        .filter(|child| {
+            disambiguator.is_none_or(|disambiguator| child.res.matches_ns(disambiguator.ns()))
+        })
+        .map(|child| child.ident.name)
+        .filter(|&name| name != lookup)
+        .collect::<Vec<_>>();
+    let Some(candidate) = find_best_match_for_name(&candidates, lookup, None) else {
+        return;
+    };
+
+    let msg = format!("there's a similarly named item `{candidate}`");
+    if let (Some(span), MarkdownLinkRange::Destination(range)) = (span, link_range) {
+        let link = &dox[range.clone()];
+        // A partial resolution means that the unresolved name follows a resolved parent path.
+        let start = if has_partial_res { link.rfind(unresolved) } else { link.find(unresolved) };
+        if let Some(start) = start {
+            let mut suggestion = link.to_owned();
+            suggestion.replace_range(start..start + unresolved.len(), candidate.as_str());
+            diag.span_suggestion_verbose(span, msg, suggestion, Applicability::MaybeIncorrect);
+            return;
+        }
+    }
+    diag.help(msg);
+}
+
 /// Reports a link that failed to resolve.
 ///
 /// This also tries to resolve any intermediate path segments that weren't
@@ -2135,6 +2186,20 @@ fn resolution_failure(
                             diag.note(note);
                         }
 
+                        if !path_is_invalid {
+                            suggest_path_name_typo(
+                                collector,
+                                diag,
+                                sp,
+                                &link_range,
+                                diag_info.dox,
+                                module,
+                                unresolved,
+                                partial_res.is_some(),
+                                disambiguator,
+                            );
+                        }
+
                         if !path_str.contains("::") {
                             if disambiguator.is_none_or(|d| d.ns() == MacroNS)
                                 && collector

tests/rustdoc-ui/intra-doc/auxiliary/typo-imported-item-issue-159496.md

@@ -0,0 +1 @@
+Creates a [Hashmap].

tests/rustdoc-ui/intra-doc/html-as-generics-intra-doc.stderr

@@ -10,6 +10,11 @@ note: the lint level is defined here
    |
 LL | #![deny(rustdoc::broken_intra_doc_links)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+help: there's a similarly named item `ExistentStruct`
+   |
+LL - /// This [test][NonExistentStruct<i32>] thing!
+LL + /// This [test][ExistentStruct<i32>] thing!
+   |
 
 error: unresolved link to `NonExistentStruct2`
   --> $DIR/html-as-generics-intra-doc.rs:17:11
@@ -18,6 +23,11 @@ LL | /// This [NonExistentStruct2<i32>] thing!
    |           ^^^^^^^^^^^^^^^^^^^^^^^ no item named `NonExistentStruct2` in scope
    |
    = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
+help: there's a similarly named item `ExistentStruct`
+   |
+LL - /// This [NonExistentStruct2<i32>] thing!
+LL + /// This [ExistentStruct<i32>] thing!
+   |
 
 error: unresolved link to `NonExistentStruct3`
   --> $DIR/html-as-generics-intra-doc.rs:22:11
@@ -26,6 +36,11 @@ LL | /// This [NonExistentStruct3<i32>][] thing!
    |           ^^^^^^^^^^^^^^^^^^^^^^^ no item named `NonExistentStruct3` in scope
    |
    = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
+help: there's a similarly named item `ExistentStruct`
+   |
+LL - /// This [NonExistentStruct3<i32>][] thing!
+LL + /// This [ExistentStruct<i32>][] thing!
+   |
 
 error: unclosed HTML tag `i32`
   --> $DIR/html-as-generics-intra-doc.rs:9:25

tests/rustdoc-ui/intra-doc/reference-links.stderr

@@ -9,6 +9,10 @@ note: the lint level is defined here
    |
 LL | #![deny(rustdoc::broken_intra_doc_links)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+help: there's a similarly named item `Command`
+   |
+LL | //! [a]: std::process::Command
+   |                              +
 
 error: aborting due to 1 previous error
 

tests/rustdoc-ui/intra-doc/typo-imported-item-issue-159496.rs

@@ -0,0 +1,27 @@
+// Suggest similarly named module items, including imports, for unresolved intra-doc links.
+
+#![deny(rustdoc::broken_intra_doc_links)]
+
+use std::collections::HashMap;
+
+/// Creates a [Hashmap].
+//~^ ERROR unresolved link to `Hashmap`
+pub fn create() {
+    let _: Option<HashMap<(), ()>> = None;
+}
+
+/// Creates a [std::collections::Hashmap].
+//~^ ERROR unresolved link to `std::collections::Hashmap`
+pub fn qualified() {}
+
+/// Creates a [type@Hashmap].
+//~^ ERROR unresolved link to `Hashmap`
+pub fn disambiguated() {}
+
+/// Creates a [`Hashmap<Hashmap>`].
+//~^ ERROR unresolved link to `Hashmap`
+pub fn generic() {}
+
+#[doc = include_str!("auxiliary/typo-imported-item-issue-159496.md")]
+//~? ERROR unresolved link to `Hashmap`
+pub fn included() {}

tests/rustdoc-ui/intra-doc/typo-imported-item-issue-159496.stderr

@@ -0,0 +1,71 @@
+error: unresolved link to `Hashmap`
+  --> $DIR/typo-imported-item-issue-159496.rs:7:16
+   |
+LL | /// Creates a [Hashmap].
+   |                ^^^^^^^ no item named `Hashmap` in scope
+   |
+   = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
+note: the lint level is defined here
+  --> $DIR/typo-imported-item-issue-159496.rs:3:9
+   |
+LL | #![deny(rustdoc::broken_intra_doc_links)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+help: there's a similarly named item `HashMap`
+   |
+LL - /// Creates a [Hashmap].
+LL + /// Creates a [HashMap].
+   |
+
+error: unresolved link to `std::collections::Hashmap`
+  --> $DIR/typo-imported-item-issue-159496.rs:13:16
+   |
+LL | /// Creates a [std::collections::Hashmap].
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^ no item named `Hashmap` in module `collections`
+   |
+help: there's a similarly named item `HashMap`
+   |
+LL - /// Creates a [std::collections::Hashmap].
+LL + /// Creates a [std::collections::HashMap].
+   |
+
+error: unresolved link to `Hashmap`
+  --> $DIR/typo-imported-item-issue-159496.rs:17:16
+   |
+LL | /// Creates a [type@Hashmap].
+   |                ^^^^^^^^^^^^ no item named `Hashmap` in scope
+   |
+   = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
+help: there's a similarly named item `HashMap`
+   |
+LL - /// Creates a [type@Hashmap].
+LL + /// Creates a [type@HashMap].
+   |
+
+error: unresolved link to `Hashmap`
+  --> $DIR/typo-imported-item-issue-159496.rs:21:17
+   |
+LL | /// Creates a [`Hashmap<Hashmap>`].
+   |                 ^^^^^^^^^^^^^^^^ no item named `Hashmap` in scope
+   |
+   = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
+help: there's a similarly named item `HashMap`
+   |
+LL - /// Creates a [`Hashmap<Hashmap>`].
+LL + /// Creates a [`HashMap<Hashmap>`].
+   |
+
+error: unresolved link to `Hashmap`
+  --> $DIR/auxiliary/typo-imported-item-issue-159496.md:1:12
+   |
+LL | Creates a [Hashmap].
+   |            ^^^^^^^ no item named `Hashmap` in scope
+   |
+   = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
+help: there's a similarly named item `HashMap`
+   |
+LL - Creates a [Hashmap].
+LL + Creates a [HashMap].
+   |
+
+error: aborting due to 5 previous errors
+