Bugfix/#421 xpath (#435)

* Fixed attr retrieval using XPATH in CDP

* Updated single node value in CDP

* Added e2e test

* Fixed attr retrieval with XPATH for HTTP driver

* Update Makefile

* Update attr.fql

e2e/tests/dynamic/doc/xpath/attr.fql

@@ -0,0 +1,6 @@
+LET url = @dynamic
+LET page = DOCUMENT(url, { driver: "cdp" })
+
+LET actual = XPATH(page, "//meta/@charset")
+
+RETURN EXPECT(["utf-8"], actual)

e2e/tests/dynamic/doc/xpath/count.fql

@@ -1,5 +1,5 @@
 LET url = @dynamic
-LET page = DOCUMENT(url, true)
+LET page = DOCUMENT(url, { driver: "cdp" })
 
 LET actual = XPATH(page, "count(//body)")
 

e2e/tests/dynamic/doc/xpath/query.fql

@@ -1,5 +1,5 @@
 LET url = @dynamic + "?redirect=/forms"
-LET page = DOCUMENT(url, true)
+LET page = DOCUMENT(url, { driver: "cdp" })
 
 LET actual = XPATH(page, "//div[contains(@class, 'form-group')]")
 

e2e/tests/static/doc/xpath/attr.fql

@@ -0,0 +1,6 @@
+LET url = @static + '/simple.html'
+LET page = DOCUMENT(url)
+
+LET actual = XPATH(page, "//meta/@charset")
+
+RETURN EXPECT(["UTF-8"], actual)

pkg/drivers/cdp/dom/element.go

@@ -627,6 +627,19 @@ func (el *HTMLElement) XPath(ctx context.Context, expression values.String) (res
 				continue
 			}
 
+			// it's not a Node, it's an attr value
+			if descr.Value.ObjectID == nil {
+				var value interface{}
+
+				if err := json.Unmarshal(descr.Value.Value, &value); err != nil {
+					return values.None, err
+				}
+
+				result.Push(values.Parse(value))
+
+				continue
+			}
+
 			repl, err := el.client.DOM.RequestNode(ctx, dom.NewRequestNodeArgs(*descr.Value.ObjectID))
 
 			if err != nil {
@@ -656,7 +669,13 @@ func (el *HTMLElement) XPath(ctx context.Context, expression values.String) (res
 		return result, nil
 	case "object":
 		if out.ObjectID == nil {
-			return values.None, nil
+			var value interface{}
+
+			if err := json.Unmarshal(out.Value, &value); err != nil {
+				return values.None, err
+			}
+
+			return values.Parse(value), nil
 		}
 
 		repl, err := el.client.DOM.RequestNode(ctx, dom.NewRequestNodeArgs(*out.ObjectID))

pkg/drivers/cdp/templates/xpath.go

@@ -2,6 +2,9 @@ package templates
 
 const xPathTemplate = `
 		(element, expression) => {
+			const unwrap = (item) => {
+				return item.nodeType != 2 ? item : item.nodeValue;
+			};
 			const out = document.evaluate(
 				expression,
 				element,
@@ -17,7 +20,7 @@ const xPathTemplate = `
 					let item;
 		
 					while ((item = out.iterateNext())) {
-						result.push(item);
+						result.push(unwrap(item));
 					}
 		
 					break;
@@ -30,7 +33,7 @@ const xPathTemplate = `
 						const item = out.snapshotItem(i);
 		
 						if (item != null) {
-							result.push(item);
+							result.push(unwrap(item));
 						}
 					}
 					break;
@@ -49,7 +52,7 @@ const xPathTemplate = `
 				}
 				case XPathResult.ANY_UNORDERED_NODE_TYPE:
 				case XPathResult.FIRST_ORDERED_NODE_TYPE: {
-					result = out.singleNodeValue;
+					result = unwrap(out.singleNodeValue);
 					break;
 				}
 				default: {

pkg/drivers/http/helpers.go

@@ -15,20 +15,26 @@ import (
 )
 
 func parseXPathNode(nav *htmlquery.NodeNavigator) (core.Value, error) {
-	node := nav.Current()
-
-	if node == nil {
-		return values.None, nil
-	}
-
 	switch nav.NodeType() {
 	case xpath.ElementNode:
+		node := nav.Current()
+
+		if node == nil {
+			return values.None, nil
+		}
+
 		return NewHTMLElement(&goquery.Selection{Nodes: []*html.Node{node}})
 	case xpath.RootNode:
+		node := nav.Current()
+
+		if node == nil {
+			return values.None, nil
+		}
+
 		url := htmlquery.SelectAttr(node, "url")
 		return NewHTMLDocument(goquery.NewDocumentFromNode(node), url, nil)
 	default:
-		return values.Parse(node.Data), nil
+		return values.NewString(nav.Value()), nil
 	}
 }