Bug 1635970 - Extended support for XPath expressions in Inspector search. r=jdescottes

The limitation to expressions starting with a slash was lifted in order to allow searching via other possible XPath expressions like `id("foo")` or `(//div)[2]`.

Differential Revision: https://phabricator.services.mozilla.com/D80963

devtools/server/actors/utils/walker-search.js

@@ -210,8 +210,7 @@ WalkerSearch.prototype = {
   },
 
   _searchXPath: function(query, options, results) {
-    const isXPath = query && query.startsWith("/");
-    if (!options.types.includes("xpath") || !isXPath) {
+    if (!options.types.includes("xpath")) {
       return;
     }
 

devtools/server/tests/browser/browser_inspector-search.js

@@ -183,6 +183,18 @@ add_task(async function() {
             },
           ],
         },
+        {
+          desc: "Search using XPath grouping expression",
+          search: "(//*)[2]",
+          expected: [{ node: inspectee.querySelector("head"), type: "xpath" }],
+        },
+        {
+          desc: "Search using XPath function",
+          search: "id('arrows')",
+          expected: [
+            { node: inspectee.querySelector("#arrows"), type: "xpath" },
+          ],
+        },
       ];
 
       const isDeeply = (a, b, msg) => {