Add check for trait impl method anchor

tests/rustdoc-gui/anchors.goml

@@ -45,6 +45,22 @@ define-function: (
             {"color": |src_link_color|, "text-decoration": "none"},
         )
 
+        // Now we ensure that the `§` anchor is "reachable" for users on trait methods.
+        // To ensure the anchor is not hovered, we move the cursor to another item.
+        move-cursor-to: "#search-button"
+        // By default, the anchor is not displayed.
+        wait-for-css: ("#method\.vroum .anchor", {"display": "none"})
+        // Once we move the cursor to the method, the anchor should appear.
+        move-cursor-to: "#method\.vroum .code-header"
+        assert-css-false: ("#method\.vroum .anchor", {"display": "none"})
+        // Now we move the cursor to the anchor to check there is no gap between the method and the
+        // anchor, making the anchor disappear and preventing users to click on it.
+        // To make it work, we need to first move it between the method and the anchor.
+        store-position: ("#method\.vroum .code-header", {"x": method_x, "y": method_y})
+        move-cursor-to: (|method_x| - 2, |method_y|)
+        // Anchor should still be displayed.
+        assert-css-false: ("#method\.vroum .anchor", {"display": "none"})
+
         go-to: "file://" + |DOC_PATH| + "/test_docs/struct.HeavilyDocumentedStruct.html"
         // Since we changed page, we need to set the theme again.
         call-function: ("switch-theme", {"theme": |theme|})

tests/rustdoc-gui/src/staged_api/lib.rs

@@ -4,6 +4,10 @@
 #![stable(feature = "some_feature", since = "1.3.5")]
 #![doc(rust_logo)]
 
+pub trait X {
+    fn vroum();
+}
+
 #[stable(feature = "some_feature", since = "1.3.5")]
 pub struct Foo {}
 
@@ -13,3 +17,7 @@ pub fn bar() {}
     #[stable(feature = "some_other_feature", since = "1.3.6")]
     pub fn yo() {}
 }
+
+impl X for Foo {
+    fn vroum() {}
+}