Add anchor for intra-doc links to associated items

Author: ncrothers

src/tools/rust-analyzer/crates/ide/src/doc_links.rs

@@ -379,13 +379,15 @@ fn rewrite_intra_doc_link(
     let resolved = resolve_doc_path_for_def(db, def, link, ns)?;
     let mut url = get_doc_base_urls(db, resolved, None, None).0?;
 
-    let (_, file, _) = filename_and_frag_for_def(db, resolved)?;
+    let (_, file, frag) = filename_and_frag_for_def(db, resolved)?;
     if let Some(path) = mod_path_of_def(db, resolved) {
         url = url.join(&path).ok()?;
     }
 
+    let frag = anchor.or(frag.as_deref());
+
     url = url.join(&file).ok()?;
-    url.set_fragment(anchor);
+    url.set_fragment(frag);
 
     Some((url.into(), strip_prefixes_suffixes(title).to_owned()))
 }
@@ -621,11 +623,9 @@ fn filename_and_frag_for_def(
             format!("fn.{}.html", f.name(db).as_str())
         }
         Definition::Variant(ev) => {
-            format!(
-                "enum.{}.html#variant.{}",
-                ev.parent_enum(db).name(db).as_str(),
-                ev.name(db).as_str()
-            )
+            let def = Definition::Adt(ev.parent_enum(db).into());
+            let (_, file, _) = filename_and_frag_for_def(db, def)?;
+            return Some((def, file, Some(format!("variant.{}", ev.name(db).as_str()))));
         }
         Definition::Const(c) => {
             format!("const.{}.html", c.name(db)?.as_str())

src/tools/rust-analyzer/crates/ide/src/doc_links/tests.rs

@@ -686,3 +686,95 @@ fn rewrite_intra_doc_link_with_anchor() {
         expect!["[PartialEq#derivable](https://doc.rust-lang.org/stable/core/cmp/trait.PartialEq.html#derivable)"],
     );
 }
+
+#[test]
+fn rewrite_intra_doc_link_to_associated_item() {
+    check_rewrite(
+        r#"
+//- /main.rs crate:foo
+/// [Foo::bar]
+pub struct $0Foo;
+
+impl Foo {
+    fn bar() {}
+}
+"#,
+        expect![[r#"[Foo::bar](https://docs.rs/foo/*/foo/struct.Foo.html#method.bar)"#]],
+    );
+    check_rewrite(
+        r#"
+//- /main.rs crate:foo
+/// [Foo::bar]
+pub struct $0Foo {
+    bar: ()
+}
+"#,
+        expect![[r#"[Foo::bar](https://docs.rs/foo/*/foo/struct.Foo.html#structfield.bar)"#]],
+    );
+    check_rewrite(
+        r#"
+//- /main.rs crate:foo
+/// [Foo::Bar]
+pub enum $0Foo {
+    Bar
+}
+"#,
+        expect![[r#"[Foo::Bar](https://docs.rs/foo/*/foo/enum.Foo.html#variant.Bar)"#]],
+    );
+    check_rewrite(
+        r#"
+//- /main.rs crate:foo
+/// [Foo::BAR]
+pub struct $0Foo;
+
+impl Foo {
+    const BAR: () = ();
+}
+"#,
+        expect![[
+            r#"[Foo::BAR](https://docs.rs/foo/*/foo/struct.Foo.html#associatedconstant.BAR)"#
+        ]],
+    );
+    check_rewrite(
+        r#"
+//- /main.rs crate:foo
+/// [Foo::bar]
+pub trait $0Foo {
+    fn bar();
+}
+"#,
+        expect![[r#"[Foo::bar](https://docs.rs/foo/*/foo/trait.Foo.html#tymethod.bar)"#]],
+    );
+    check_rewrite(
+        r#"
+//- /main.rs crate:foo
+/// [Foo::Bar]
+pub trait $0Foo {
+    type Bar;
+}
+"#,
+        expect![[r#"[Foo::Bar](https://docs.rs/foo/*/foo/trait.Foo.html#associatedtype.Bar)"#]],
+    );
+    check_rewrite(
+        r#"
+//- /main.rs crate:foo
+/// [Foo::bar#anchor]
+pub struct $0Foo {
+    bar: (),
+}
+"#,
+        expect![[r#"[Foo::bar#anchor](https://docs.rs/foo/*/foo/struct.Foo.html#anchor)"#]],
+    );
+    check_rewrite(
+        r#"
+//- /main.rs crate:foo
+/// [method](Foo::bar)
+pub struct $0Foo;
+
+impl Foo {
+    fn bar() {}
+}
+"#,
+        expect![[r#"[method](https://docs.rs/foo/*/foo/struct.Foo.html#method.bar)"#]],
+    );
+}