Merge pull request #13 from AngleSharp/devel

0.16.0

Author: egil

src/AngleSharp.Diffing.Tests/AngleSharp.DiffingTests.csproj

@@ -1,15 +1,16 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFramework>net5.0</TargetFramework>
     <IsPackable>false</IsPackable>
     <AssemblyName>AngleSharp.Diffing.Tests</AssemblyName>
     <RootNamespace>AngleSharp.Diffing</RootNamespace>
     <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies> <!-- https://github.com/Tyrrrz/GitHubActionsTestLogger/issues/5 -->
+    <Nullable>annotations</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.9.4" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.10.0" />
     <PackageReference Include="GitHubActionsTestLogger" Version="1.2.0" />
     <PackageReference Include="Shouldly" Version="4.0.3" />
     <PackageReference Include="xunit" Version="2.4.1" />

src/AngleSharp.Diffing.Tests/Strategies/DiffingStrategyPipelineTest.cs

@@ -1,10 +1,7 @@
 using System;
 using System.Linq;
-
 using AngleSharp.Diffing.Core;
-
 using Shouldly;
-
 using Xunit;
 
 namespace AngleSharp.Diffing.Strategies
@@ -22,7 +19,7 @@ public DiffingStrategyPipelineTest(DiffingTestFixture fixture) : base(fixture)
             _ => throw new InvalidOperationException()
         };
 
-        [Fact(DisplayName = "Wen zero filter strategies have been added, true is returned")]
+        [Fact(DisplayName = "When zero filter strategies have been added, true is returned")]
         public void Test1()
         {
             var sut = new DiffingStrategyPipeline();

src/AngleSharp.Diffing/Core/ComparisonSource.cs

@@ -107,10 +107,10 @@ private static int GetNodeIndex(INode node)
         private static string CalculateParentPath(INode node)
         {
             var result = string.Empty;
-            foreach (var parent in node.GetParents().TakeWhile(x => x.Parent is { }))
+            foreach (var parent in node.GetParents().TakeWhile(x => x.Parent is not null))
             {
                 var pathSegment = GetNodePathSegment(parent);
-                if (pathSegment is { })
+                if (pathSegment is not null)
                     result = CombinePath(pathSegment, result);
             }
             return result;
@@ -120,13 +120,16 @@ private static int GetPathIndex(INode node)
         {
             var result = 0;
             var parent = node.Parent;
-            var childNodes = parent.ChildNodes;
-            for (int index = 0; index < childNodes.Length; index++)
+            if (parent is not null)
             {
-                if (ReferenceEquals(childNodes[index], node))
-                    return result;
-                if (childNodes[index] is IParentNode)
-                    result += 1;
+                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;
+                }
             }
             throw new InvalidOperationException("Unexpected node tree state. The node was not found in its parents child nodes collection.");
         }

src/AngleSharp.Diffing/DiffBuilder.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 
 using AngleSharp.Diffing.Core;
+using AngleSharp.Diffing.Extensions;
 using AngleSharp.Diffing.Strategies;
 using AngleSharp.Dom;
 using AngleSharp.Html.Parser;
@@ -35,7 +36,7 @@ private DiffBuilder(string control)
             Control = control;
             var config = Configuration.Default.WithCss();
             _context = BrowsingContext.New(config);
-            _htmlParser = _context.GetService<IHtmlParser>();
+            _htmlParser = _context.GetService<IHtmlParser>() ?? throw new InvalidOperationException("No IHtmlParser registered in the default AngleSharp browsing context.");
             _document = _context.OpenNewAsync().Result;
         }
 
@@ -88,7 +89,7 @@ public IEnumerable<IDiff> Build()
         /// </summary>
         protected INodeList Parse(string html)
         {
-            return _htmlParser.ParseFragment(html, _document.Body);
+            return _htmlParser.ParseFragment(html, _document.Body ?? throw new UnexpectedDOMTreeStructureException());
         }
     }
 }

src/AngleSharp.Diffing/Extensions/ElementExtensions.cs

@@ -96,7 +96,7 @@ public static T GetInlineOptionOrDefault<T>(this IElement startElement, string o
 
             var element = startElement;
 
-            while (element is { })
+            while (element is not null)
             {
                 if (element.Attributes[optionName] is IAttr attr)
                 {
@@ -139,7 +139,7 @@ public static bool TryGetNodeIndex(this INode node, [NotNullWhen(true)] out int
         public static IEnumerable<INode> GetParents(this INode node)
         {
             var parent = node.Parent;
-            while (parent is { })
+            while (parent is not null)
             {
                 yield return parent;
                 parent = parent.Parent;

src/AngleSharp.Diffing/Extensions/NodeExtensions.cs

@@ -26,7 +26,9 @@ public static bool TryGetAttr(this INode node, string attributeName, [NotNullWhe
         {
             if (node is IElement element && element.HasAttribute(attributeName))
             {
-                attribute = element.Attributes[attributeName];
+                // BANG: element.HasAttribute is used to ensure that the attributes indexer
+                //       returns a non-null IAttr value.
+                attribute = element.Attributes[attributeName]!;
                 return true;
             }
             else

src/AngleSharp.Diffing/Extensions/UnexpectedDOMTreeStructureException.cs

@@ -0,0 +1,22 @@
+using System;
+using System.Runtime.Serialization;
+
+namespace AngleSharp.Diffing.Extensions
+{
+    /// <summary>
+    /// Represents an exception that is thrown when a part of the DOM tree is not as expected.
+    /// Generally not supposed to happen.
+    /// </summary>
+    [Serializable]
+    public sealed class UnexpectedDOMTreeStructureException : Exception
+    {
+        /// <summary>
+        /// Creates an instance of the <see cref="UnexpectedDOMTreeStructureException"/>.
+        /// </summary>
+        public UnexpectedDOMTreeStructureException()
+            : base("The DOM tree structure was not as expected by AngleSharp.Diffing.") { }
+
+        private UnexpectedDOMTreeStructureException(SerializationInfo info, StreamingContext context)
+            : base(info, context) { }
+    }
+}

src/AngleSharp.Diffing/HtmlDiffer.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Collections.Generic;
-
 using AngleSharp.Diffing.Core;
+using AngleSharp.Diffing.Extensions;
 using AngleSharp.Dom;
 using AngleSharp.Html.Parser;
 
@@ -26,7 +26,7 @@ public HtmlDiffer(IDiffingStrategy diffingStrategy)
             _diffingStrategy = diffingStrategy ?? throw new ArgumentNullException(nameof(diffingStrategy));
             var config = Configuration.Default.WithCss();
             _context = BrowsingContext.New(config);
-            _htmlParser = _context.GetService<IHtmlParser>();
+            _htmlParser = _context.GetService<IHtmlParser>() ?? throw new InvalidOperationException("No IHtmlParser registered in the default AngleSharp browsing context.");
             _document = _context.OpenNewAsync().Result;
         }
 
@@ -103,7 +103,7 @@ public IEnumerable<IDiff> Compare(IEnumerable<INode> controlNodes, IEnumerable<I
         /// </summary>
         protected INodeList Parse(string html)
         {
-            return _htmlParser.ParseFragment(html, _document.Body);
+            return _htmlParser.ParseFragment(html, _document.Body ?? throw new UnexpectedDOMTreeStructureException());
         }
     }
 }

src/AngleSharp.Diffing/Strategies/ElementStrategies/CssSelectorElementMatcher.cs

@@ -55,7 +55,7 @@ private static bool TryGetTestNode(IDiffContext context, string cssSelector, [No
                 _ => throw new DiffMatchSelectorReturnedTooManyResultsException($@"The CSS selector ""{cssSelector}"" returned {searchResult.Length} matches from the test node tree. No more than one is allowed.")
             };
 
-            return testNode is { };
+            return testNode is not null;
         }
     }
 }

src/AngleSharp.Diffing/Strategies/TextNodeStrategies/StyleSheetTextNodeComparer.cs

@@ -36,7 +36,7 @@ private static bool TryGetStyleDeclaretions(in Comparison comparison, [NotNullWh
                 controlStyles = controlParentStyle?.Sheet;
                 testStyles = testParentStyle?.Sheet;
 
-                return controlStyles is { } && testStyles is { };
+                return controlStyles is not null && testStyles is not null;
             }
             else
                 return false;