Add regression test for #118195

Author: GuillaumeGomez

tests/rustdoc/enum-variant-fields-heading.rs

@@ -0,0 +1,18 @@
+// This is a regression test for <https://github.com/rust-lang/rust/issues/118195>.
+// It ensures that the "Fields" heading is not generated if no field is displayed.
+
+#![crate_name = "foo"]
+
+// @has 'foo/enum.Foo.html'
+// @has - '//*[@id="variant.A"]' 'A'
+// @count - '//*[@id="variant.A.fields"]' 0
+// @has - '//*[@id="variant.B"]' 'B'
+// @count - '//*[@id="variant.B.fields"]' 0
+// @snapshot variants - '//*[@id="main-content"]/*[@class="variants"]'
+
+pub enum Foo {
+    /// A variant with no fields
+    A {},
+    /// A variant with hidden fields
+    B { #[doc(hidden)] a: u8 },
+}

tests/rustdoc/enum-variant-fields-heading.variants.html

@@ -0,0 +1,3 @@
+<div class="variants"><section id="variant.A" class="variant"><a href="#variant.A" class="anchor">&#167;</a><h3 class="code-header">A</h3></section><div class="docblock"><p>A variant with no fields</p>
+</div><section id="variant.B" class="variant"><a href="#variant.B" class="anchor">&#167;</a><h3 class="code-header">B</h3></section><div class="docblock"><p>A variant with hidden fields</p>
+</div></div>