fix(breaking): Change Core.ComparisonSource.GetPathIndex() to return the Index inside ChildNodes instead of Children

Closes #20

Author: edxlhornung

CHANGELOG.md

@@ -3,6 +3,7 @@
 Released on Tuesday, February 15, 2022.
 
 - Added a new style comparer which orders the styles before comparing them. By [@grishat](https://github.com/SebastianStehle).
+- Change Core.ComparisonSource.GetPathIndex() to return the index inside ChildNodes instead of Children. By [@edxlhornung](https://github.com/edxlhornung).
 
 # 0.17.0
 

src/AngleSharp.Diffing.Tests/Core/ComparisonSourceTest.cs

@@ -68,12 +68,13 @@ public void Test002()
         }
 
         [Theory(DisplayName = "The index in the source's path is based on its position in it's parents" +
-            "child node list, i.e. excluding other node types that does not contain children")]
+            "child node list")]
         [InlineData("<p>", 0, "p(0)")]
-        [InlineData("text<p>", 1, "p(0)")]
-        [InlineData("<!--x--><p>", 1, "p(0)")]
-        [InlineData("<i></i>text<p>", 2, "p(1)")]
-        [InlineData("<i></i><!--x--><p>", 2, "p(1)")]
+        [InlineData("text<p>", 1, "p(1)")]
+        [InlineData("<!--x--><p>", 1, "p(1)")]
+        [InlineData("<i></i>text<p>", 2, "p(2)")]
+        [InlineData("<i></i><!--x--><p>", 2, "p(2)")]
+        [InlineData("<i></i>text<!--x--><p>text", 2, "#comment(2)")]
         public void Test005(string sourceMarkup, int nodeIndex, string expectedPath)
         {
             var node = ToNodeList(sourceMarkup)[nodeIndex];
@@ -91,7 +92,7 @@ public void Test006()
 
             var sut = new ComparisonSource(textNode, ComparisonSourceType.Control);
 
-            sut.Path.ShouldBe("p(0) > i(1) > #text(0)");
+            sut.Path.ShouldBe("p(0) > i(2) > #text(0)");
         }
 
         [Fact(DisplayName = "Source uses parent path if provided to construct own path")]

src/AngleSharp.Diffing/Core/ComparisonSource.cs

@@ -118,17 +118,14 @@ private static string CalculateParentPath(INode node)
 
         private static int GetPathIndex(INode node)
         {
-            var result = 0;
             var parent = node.Parent;
             if (parent is not null)
             {
                 var childNodes = parent.ChildNodes;
                 for (int index = 0; index < childNodes.Length; index++)
                 {
                     if (ReferenceEquals(childNodes[index], node))
-                        return result;
-                    if (childNodes[index] is IParentNode)
-                        result += 1;
+                        return index;
                 }
             }
             throw new InvalidOperationException("Unexpected node tree state. The node was not found in its parents child nodes collection.");