fix #102

build.go

@@ -449,10 +449,16 @@ func (b *builder) processFunction(root *functionNode, props *builderProp) (query
 		}
 		qyOutput = &functionQuery{Func: stringLengthFunc(arg1)}
 	case "normalize-space":
-		if len(root.Args) == 0 {
-			return nil, errors.New("xpath: normalize-space function must have at least one parameter")
+		var arg node
+		if len(root.Args) > 0 {
+			arg = root.Args[0]
+		} else {
+			arg = &axisNode{
+				AxeType:  "self",
+				nodeType: nodeAxis,
+			}
 		}
-		argQuery, err := b.processNode(root.Args[0], flagsEnum.None, props)
+		argQuery, err := b.processNode(arg, flagsEnum.None, props)
 		if err != nil {
 			return nil, err
 		}

xpath_function_test.go

@@ -226,11 +226,14 @@ func Test_func_namespace_uri(t *testing.T) {
 func Test_func_normalize_space(t *testing.T) {
 	const testStr = "\t    \rloooooooonnnnnnngggggggg  \r \n tes  \u00a0 t strin \n\n \r g "
 	const expectedStr = `loooooooonnnnnnngggggggg tes t strin g`
-	test_xpath_eval(t, employee_example, `normalize-space("`+testStr+`")`, expectedStr)
-
+	test_xpath_eval(t, empty_example, `normalize-space("`+testStr+`")`, expectedStr)
 	test_xpath_eval(t, empty_example, `normalize-space(' abc ')`, "abc")
+	n := selectNode(employee_example, `//employee[@id="1"]/name`)
+	test_xpath_eval(t, n, `normalize-space()`, "Opal Kole")
+	test_xpath_eval(t, n, `normalize-space(.)`, "Opal Kole")
 	test_xpath_eval(t, book_example, `normalize-space(//book/title)`, "Everyday Italian")
 	test_xpath_eval(t, book_example, `normalize-space(//book[1]/title)`, "Everyday Italian")
+
 }
 
 func Test_func_lower_case(t *testing.T) {