Less: Fix incorrect comment in selector() (#8707)

src/language-css/printer-postcss.js

@@ -20,6 +20,7 @@ const {
     indent,
     dedent,
     ifBreak,
+    breakParent,
   },
   utils: { removeLines },
 } = require("../document");
@@ -501,6 +502,23 @@ function genericPrint(path, options, print) {
         return options.originalText.slice(start, end).trim();
       }
 
+      // Same reason above
+      const grandParent = path.getParentNode(1);
+      if (
+        parentNode.type === "value-paren_group" &&
+        grandParent &&
+        grandParent.type === "value-func" &&
+        grandParent.value === "selector"
+      ) {
+        const start = options.locStart(parentNode.open) + 1;
+        const end = options.locEnd(parentNode.close) - 1;
+        const selector = options.originalText.slice(start, end).trim();
+
+        return lastLineHasInlineComment(selector)
+          ? concat([breakParent, selector])
+          : selector;
+      }
+
       return node.value;
     }
     // postcss-values-parser

tests/less/function-selector/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,26 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`selector.less format 1`] = `
+====================================options=====================================
+parsers: ["less"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+@supports selector(
+:focus-visible // *"a"
+) {
+a{color:#f00
+}
+}
+
+=====================================output=====================================
+@supports selector(
+  :focus-visible // *"a"
+) {
+  a {
+    color: #f00;
+  }
+}
+
+================================================================================
+`;

tests/less/function-selector/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname, ["less"]);

tests/less/function-selector/selector.less

@@ -0,0 +1,6 @@
+@supports selector(
+:focus-visible // *"a"
+) {
+a{color:#f00
+}
+}