[dotnet]: Adding ability to use By object with relative locators

Also marking RelativeBy.WithTagName as obsolete. Users should change
their calls to `RelativeBy.WithLocator(By.TagName(...))`.

Author: jimevans

dotnet/src/webdriver/RelativeBy.cs

@@ -70,6 +70,7 @@ private RelativeBy(object root, List<object> filters) : this()
         /// </summary>
         /// <param name="tagName">The tag name of the element to find.</param>
         /// <returns>A <see cref="RelativeBy"/> object to be used in finding the elements.</returns>
+        [Obsolete("Use the WithLocator method instead, passing By.TagName.")]
         public static RelativeBy WithTagName(string tagName)
         {
             if (string.IsNullOrEmpty(tagName))
@@ -80,6 +81,17 @@ public static RelativeBy WithTagName(string tagName)
             return new RelativeBy(By.TagName(tagName));
         }
 
+        /// <summary>
+        /// Creates a new <see cref="RelativeBy"/> for finding elements with the specified tag name.
+        /// </summary>
+        /// <param name="by">A By object that will be used to find the initial element.</param>
+        /// <returns>A <see cref="RelativeBy"/> object to be used in finding the elements.</returns>
+        public static RelativeBy WithLocator(By by)
+        {
+            return new RelativeBy(by);
+        }
+
+
         /// <summary>
         /// Finds the first element matching the criteria.
         /// </summary>
@@ -111,7 +123,7 @@ public override ReadOnlyCollection<IWebElement> FindElements(ISearchContext cont
             filterParameters["filters"] = this.filters;
             parameters["relative"] = filterParameters;
             object rawElements = js.ExecuteScript(wrappedAtom, parameters);
-            ReadOnlyCollection<IWebElement> elements = rawElements as ReadOnlyCollection<IWebElement>; 
+            ReadOnlyCollection<IWebElement> elements = rawElements as ReadOnlyCollection<IWebElement>;
             return elements;
         }
 

dotnet/test/common/RelativeLocatorTest.cs

@@ -16,7 +16,7 @@ public void ShouldBeAbleToFindElementsAboveAnother()
 
             IWebElement lowest = driver.FindElement(By.Id("below"));
 
-            ReadOnlyCollection<IWebElement> elements = driver.FindElements(RelativeBy.WithTagName("p").Above(lowest));
+            ReadOnlyCollection<IWebElement> elements = driver.FindElements(RelativeBy.WithLocator(By.TagName("p")).Above(lowest));
             List<string> elementIds = new List<string>();
             foreach (IWebElement element in elements)
             {
@@ -32,7 +32,7 @@ public void ShouldBeAbleToCombineFilters()
         {
             driver.Url = (EnvironmentManager.Instance.UrlBuilder.WhereIs("relative_locators.html"));
 
-            ReadOnlyCollection<IWebElement> seen = driver.FindElements(RelativeBy.WithTagName("td").Above(By.Id("center")).RightOf(By.Id("second")));
+            ReadOnlyCollection<IWebElement> seen = driver.FindElements(RelativeBy.WithLocator(By.TagName("td")).Above(By.Id("center")).RightOf(By.Id("second")));
 
             List<string> elementIds = new List<string>();
             foreach (IWebElement element in seen)