From f3fd82cd76642db52593018d24268e5bc8e7e6e8 Mon Sep 17 00:00:00 2001
From: RiRiSharp <github@ririsharp.nl>
Date: Thu, 11 Sep 2025 17:14:07 +0200
Subject: [PATCH 1/7] Ignore unmatched :ignore attributes

---
 src/AngleSharp.Diffing.Tests/DiffBuilderTest.cs     | 13 +++++++++++++
 src/AngleSharp.Diffing/Core/HtmlDifferenceEngine.cs |  9 ++++++++-
 src/AngleSharp.Diffing/Core/SourceMap.cs            |  2 +-
 .../AttributeStrategies/IgnoreAttributeComparer.cs  |  7 ++++++-
 4 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/src/AngleSharp.Diffing.Tests/DiffBuilderTest.cs b/src/AngleSharp.Diffing.Tests/DiffBuilderTest.cs
index 9769990..67fe5ef 100644
--- a/src/AngleSharp.Diffing.Tests/DiffBuilderTest.cs
+++ b/src/AngleSharp.Diffing.Tests/DiffBuilderTest.cs
@@ -116,4 +116,17 @@ public void Test006(string control, string test)
 
         diffs.ShouldBeEmpty();
     }
+
+    [Theory(DisplayName = "When a control element has 'class:ignore', elements with and without class should return empty diffs")]
+    [InlineData("<div class=\"ian-fleming\"></div>")]
+    [InlineData("<div class=\"\"></div>")]
+    [InlineData("<div class></div>")]
+    [InlineData("<div></div>")]
+    public void Test007(string testHtml)
+    {
+        var controlHtml = "<div class:ignore></div>";
+        var diffs = DiffBuilder.Compare(controlHtml).WithTest(testHtml).Build();
+        Assert.Empty(diffs);
+    }
+
 }
diff --git a/src/AngleSharp.Diffing/Core/HtmlDifferenceEngine.cs b/src/AngleSharp.Diffing/Core/HtmlDifferenceEngine.cs
index 575ca96..3ce514f 100644
--- a/src/AngleSharp.Diffing/Core/HtmlDifferenceEngine.cs
+++ b/src/AngleSharp.Diffing/Core/HtmlDifferenceEngine.cs
@@ -1,4 +1,5 @@
 using AngleSharp.Diffing.Core.Diffs;
+using AngleSharp.Diffing.Strategies.AttributeStrategies;
 
 namespace AngleSharp.Diffing.Core;
 
@@ -160,7 +161,13 @@ void MarkSelectedSourcesAsMatched(in AttributeComparison comparison)
 
         void UpdateUnmatchedTracking()
         {
-            Context.MissingAttributeSources.AddRange(controls.GetUnmatched());
+            // Filter out unmatched :ignore attributes, they were meant to be ignored after all
+            // https://github.com/AngleSharp/AngleSharp.Diffing/issues/48
+            var controlsUnmatched = controls
+                .GetUnmatched()
+                .Where(c => !IgnoreAttributeComparer.IsIgnoreAttribute(c.Attribute));
+
+            Context.MissingAttributeSources.AddRange(controlsUnmatched);
             Context.UnexpectedAttributeSources.AddRange(tests.GetUnmatched());
         }
     }
diff --git a/src/AngleSharp.Diffing/Core/SourceMap.cs b/src/AngleSharp.Diffing/Core/SourceMap.cs
index 4f99c8d..4b30d12 100644
--- a/src/AngleSharp.Diffing/Core/SourceMap.cs
+++ b/src/AngleSharp.Diffing/Core/SourceMap.cs
@@ -70,7 +70,7 @@ public IEnumerable<AttributeComparisonSource> GetUnmatched()
     {
         foreach (var source in _sources.Values)
         {
-            if (!_matched.Contains(source.Attribute.Name))
+            if (IsUnmatched(source.Attribute.Name))
                 yield return source;
         }
     }
diff --git a/src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeComparer.cs b/src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeComparer.cs
index c74f619..087ca08 100644
--- a/src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeComparer.cs
+++ b/src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeComparer.cs
@@ -15,8 +15,13 @@ public static CompareResult Compare(in AttributeComparison comparison, CompareRe
         if (currentDecision.IsSameOrSkip)
             return currentDecision;
 
-        return comparison.Control.Attribute.Name.EndsWith(DIFF_IGNORE_POSTFIX, StringComparison.OrdinalIgnoreCase)
+        return IsIgnoreAttribute(comparison.Control.Attribute)
             ? CompareResult.Same
             : currentDecision;
     }
+
+    public static bool IsIgnoreAttribute(IAttr source)
+    {
+        return source.Name.EndsWith(DIFF_IGNORE_POSTFIX,  StringComparison.OrdinalIgnoreCase);
+    }
 }

From 80483799490ea1b89c969ce3949ece6c16455435 Mon Sep 17 00:00:00 2001
From: RiRiSharp <github@ririsharp.nl>
Date: Fri, 12 Sep 2025 23:05:31 +0200
Subject: [PATCH 2/7] Add more tests

---
 .../DiffBuilderTest.cs                        | 22 +++++++++++++------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/src/AngleSharp.Diffing.Tests/DiffBuilderTest.cs b/src/AngleSharp.Diffing.Tests/DiffBuilderTest.cs
index 67fe5ef..845b987 100644
--- a/src/AngleSharp.Diffing.Tests/DiffBuilderTest.cs
+++ b/src/AngleSharp.Diffing.Tests/DiffBuilderTest.cs
@@ -117,14 +117,22 @@ public void Test006(string control, string test)
         diffs.ShouldBeEmpty();
     }
 
-    [Theory(DisplayName = "When a control element has 'class:ignore', elements with and without class should return empty diffs")]
-    [InlineData("<div class=\"ian-fleming\"></div>")]
-    [InlineData("<div class=\"\"></div>")]
-    [InlineData("<div class></div>")]
-    [InlineData("<div></div>")]
-    public void Test007(string testHtml)
+    [Theory(DisplayName =
+        "When a control element has ':ignore', elements with and without that attribute should return empty diffs")]
+    [InlineData("<div class:ignore></div>", "<div class=\"ian-fleming\"></div>")]
+    [InlineData("<div class:ignore></div>", "<div class=\"\"></div>")]
+    [InlineData("<div class:ignore></div>", "<div class></div>")]
+    [InlineData("<div class:ignore></div>", "<div></div>")]
+    [InlineData("<input required:ignore/>", "<input required=\"required\"/>")]
+    [InlineData("<input required:ignore/>", "<input required=\"\"/>")]
+    [InlineData("<input required:ignore/>", "<input required/>")]
+    [InlineData("<input required:ignore/>", "<input/>")]
+    [InlineData("<button onclick:ignore/></button>", "<button onclick=\"alert(1)\"></button>")]
+    [InlineData("<button onclick:ignore/></button>", "<button/></button>")]
+    [InlineData("<a aria-disabled:ignore/></a>", "<a aria-disabled=\"true\"/></a>")]
+    [InlineData("<a aria-disabled:ignore/></a>", "<a/></a>")]
+    public void Test007(string controlHtml, string testHtml)
     {
-        var controlHtml = "<div class:ignore></div>";
         var diffs = DiffBuilder.Compare(controlHtml).WithTest(testHtml).Build();
         Assert.Empty(diffs);
     }

From 5f19c088bd745db5bd3e62eab69f5188603ca2dd Mon Sep 17 00:00:00 2001
From: RiRiSharp <github@ririsharp.nl>
Date: Sat, 13 Sep 2025 14:09:05 +0200
Subject: [PATCH 3/7] Add test to cover situation where no ignore attribute was
 requested

---
 .../DiffBuilderTest.cs                        | 44 ++++++++++++------
 .../TestData/IgnoreAttributeTestData.cs       | 45 +++++++++++++++++++
 2 files changed, 76 insertions(+), 13 deletions(-)
 create mode 100644 src/AngleSharp.Diffing.Tests/TestData/IgnoreAttributeTestData.cs

diff --git a/src/AngleSharp.Diffing.Tests/DiffBuilderTest.cs b/src/AngleSharp.Diffing.Tests/DiffBuilderTest.cs
index 845b987..3ec92a3 100644
--- a/src/AngleSharp.Diffing.Tests/DiffBuilderTest.cs
+++ b/src/AngleSharp.Diffing.Tests/DiffBuilderTest.cs
@@ -1,3 +1,8 @@
+using AngleSharp.Diffing.Strategies;
+using AngleSharp.Diffing.Strategies.AttributeStrategies;
+using AngleSharp.Diffing.Strategies.TextNodeStrategies;
+using AngleSharp.Diffing.TestData;
+
 namespace AngleSharp.Diffing;
 
 
@@ -119,22 +124,35 @@ public void Test006(string control, string test)
 
     [Theory(DisplayName =
         "When a control element has ':ignore', elements with and without that attribute should return empty diffs")]
-    [InlineData("<div class:ignore></div>", "<div class=\"ian-fleming\"></div>")]
-    [InlineData("<div class:ignore></div>", "<div class=\"\"></div>")]
-    [InlineData("<div class:ignore></div>", "<div class></div>")]
-    [InlineData("<div class:ignore></div>", "<div></div>")]
-    [InlineData("<input required:ignore/>", "<input required=\"required\"/>")]
-    [InlineData("<input required:ignore/>", "<input required=\"\"/>")]
-    [InlineData("<input required:ignore/>", "<input required/>")]
-    [InlineData("<input required:ignore/>", "<input/>")]
-    [InlineData("<button onclick:ignore/></button>", "<button onclick=\"alert(1)\"></button>")]
-    [InlineData("<button onclick:ignore/></button>", "<button/></button>")]
-    [InlineData("<a aria-disabled:ignore/></a>", "<a aria-disabled=\"true\"/></a>")]
-    [InlineData("<a aria-disabled:ignore/></a>", "<a/></a>")]
+    [MemberData(nameof(IgnoreAttributeTestData.ControlAndHtmlData), MemberType = typeof(IgnoreAttributeTestData))]
     public void Test007(string controlHtml, string testHtml)
     {
         var diffs = DiffBuilder.Compare(controlHtml).WithTest(testHtml).Build();
         Assert.Empty(diffs);
     }
 
-}
+    [Theory(DisplayName =
+        "When a control element has ':ignore', but IgnoreAttributeComparer is not active, diffs should be found")]
+    [MemberData(nameof(IgnoreAttributeTestData.ControlHtmlAndDiffData), MemberType = typeof(IgnoreAttributeTestData))]
+    public void Test008(string controlHtml, string testHtml, DiffResult expectedDiffResult)
+    {
+        var diffs = DiffBuilder
+            .Compare(controlHtml)
+            .WithTest(testHtml)
+            .WithOptions(a => a // Most important thing to note here is we do not have a ignore attribute comparer
+                .AddSearchingNodeMatcher()
+                .AddAttributeNameMatcher()
+                .AddElementComparer(enforceTagClosing: false)
+                .AddMatcher(PostfixedAttributeMatcher.Match, StrategyType.Specialized)
+                .AddComparer(AttributeComparer.Compare, StrategyType.Generalized)
+                .AddClassAttributeComparer()
+                .AddBooleanAttributeComparer(BooleanAttributeComparision.Strict)
+                .AddStyleAttributeComparer())
+            .Build()
+            .ToList();
+
+        Assert.Single(diffs);
+        Assert.Equal(DiffTarget.Attribute, diffs[0].Target);
+        Assert.Equal(expectedDiffResult, diffs[0].Result);
+    }
+}
\ No newline at end of file
diff --git a/src/AngleSharp.Diffing.Tests/TestData/IgnoreAttributeTestData.cs b/src/AngleSharp.Diffing.Tests/TestData/IgnoreAttributeTestData.cs
new file mode 100644
index 0000000..daded07
--- /dev/null
+++ b/src/AngleSharp.Diffing.Tests/TestData/IgnoreAttributeTestData.cs
@@ -0,0 +1,45 @@
+namespace AngleSharp.Diffing.TestData;
+
+internal static class IgnoreAttributeTestData
+{
+    public static TheoryData<string, string> ControlAndHtmlData()
+    {
+        var theoryData = new TheoryData<string, string>();
+        foreach (var (controlHtml, expectedHtml, _) in TestCases)
+        {
+            theoryData.Add(controlHtml, expectedHtml);
+        }
+
+        return theoryData;
+    }
+
+    public static TheoryData<string, string, DiffResult> ControlHtmlAndDiffData()
+    {
+        var theoryData = new TheoryData<string, string, DiffResult>();
+        foreach (var (controlHtml, expectedHtml, expectedDiffResult) in TestCases)
+        {
+            theoryData.Add(controlHtml, expectedHtml, expectedDiffResult);
+        }
+
+        return theoryData;
+    }
+
+    private static readonly IEnumerable<(string controlHtml, string expectedHtml, DiffResult expectedDiffResult)>
+        TestCases =
+        [
+            ("<div class:ignore></div>", "<div class=\"ian-fleming\"></div>", DiffResult.Different),
+            ("<div class:ignore></div>", "<div class=\"\"></div>", DiffResult.Different),
+            ("<div class:ignore></div>", "<div class></div>", DiffResult.Different),
+            ("<div class:ignore></div>", "<div></div>", DiffResult.Missing),
+            ("<input required:ignore/>", "<input required=\"required\"/>", DiffResult.Different),
+            ("<input required:ignore/>", "<input required=\"\"/>", DiffResult.Different),
+            ("<input required:ignore/>", "<input required/>", DiffResult.Different),
+            ("<input required:ignore/>", "<input/>", DiffResult.Missing),
+            ("<button onclick:ignore/></button>", "<button onclick=\"alert(1)\"></button>", DiffResult.Different),
+            ("<button onclick:ignore/></button>", "<button/></button>", DiffResult.Missing),
+            ("<a aria-disabled:ignore/></a>", "<a aria-disabled=\"true\"/></a>", DiffResult.Different),
+            ("<a aria-disabled:ignore/></a>", "<a/></a>", DiffResult.Missing),
+            ("<span style:ignore/></span>", "<span style=\"color:red;\"/></span>", DiffResult.Different),
+            ("<span style:ignore/></span>", "<span/></span>", DiffResult.Missing),
+        ];
+}
\ No newline at end of file

From e254b0cd10de2a317076aba996e9306b94a95e1c Mon Sep 17 00:00:00 2001
From: RiRiSharp <github@ririsharp.nl>
Date: Sun, 14 Sep 2025 15:48:56 +0200
Subject: [PATCH 4/7] Add :ignore filter approach

---
 .../DiffBuilderTest.cs                        |  2 +-
 .../Core/HtmlDifferenceEngine.cs              |  8 +----
 ...iffingStrategyPipelineBuilderExtensions.cs |  1 +
 .../IgnoreAttributeMatcher.cs                 | 29 +++++++++++++++++++
 4 files changed, 32 insertions(+), 8 deletions(-)
 create mode 100644 src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeMatcher.cs

diff --git a/src/AngleSharp.Diffing.Tests/DiffBuilderTest.cs b/src/AngleSharp.Diffing.Tests/DiffBuilderTest.cs
index 3ec92a3..e9ad09d 100644
--- a/src/AngleSharp.Diffing.Tests/DiffBuilderTest.cs
+++ b/src/AngleSharp.Diffing.Tests/DiffBuilderTest.cs
@@ -141,7 +141,7 @@ public void Test008(string controlHtml, string testHtml, DiffResult expectedDiff
             .WithTest(testHtml)
             .WithOptions(a => a // Most important thing to note here is we do not have a ignore attribute comparer
                 .AddSearchingNodeMatcher()
-                .AddAttributeNameMatcher()
+                .AddMatcher(AttributeNameMatcher.Match, StrategyType.Generalized)
                 .AddElementComparer(enforceTagClosing: false)
                 .AddMatcher(PostfixedAttributeMatcher.Match, StrategyType.Specialized)
                 .AddComparer(AttributeComparer.Compare, StrategyType.Generalized)
diff --git a/src/AngleSharp.Diffing/Core/HtmlDifferenceEngine.cs b/src/AngleSharp.Diffing/Core/HtmlDifferenceEngine.cs
index 3ce514f..35734aa 100644
--- a/src/AngleSharp.Diffing/Core/HtmlDifferenceEngine.cs
+++ b/src/AngleSharp.Diffing/Core/HtmlDifferenceEngine.cs
@@ -161,13 +161,7 @@ void MarkSelectedSourcesAsMatched(in AttributeComparison comparison)
 
         void UpdateUnmatchedTracking()
         {
-            // Filter out unmatched :ignore attributes, they were meant to be ignored after all
-            // https://github.com/AngleSharp/AngleSharp.Diffing/issues/48
-            var controlsUnmatched = controls
-                .GetUnmatched()
-                .Where(c => !IgnoreAttributeComparer.IsIgnoreAttribute(c.Attribute));
-
-            Context.MissingAttributeSources.AddRange(controlsUnmatched);
+            Context.MissingAttributeSources.AddRange(controls.GetUnmatched());
             Context.UnexpectedAttributeSources.AddRange(tests.GetUnmatched());
         }
     }
diff --git a/src/AngleSharp.Diffing/Strategies/AttributeStrategies/DiffingStrategyPipelineBuilderExtensions.cs b/src/AngleSharp.Diffing/Strategies/AttributeStrategies/DiffingStrategyPipelineBuilderExtensions.cs
index 17b8223..18f619b 100644
--- a/src/AngleSharp.Diffing/Strategies/AttributeStrategies/DiffingStrategyPipelineBuilderExtensions.cs
+++ b/src/AngleSharp.Diffing/Strategies/AttributeStrategies/DiffingStrategyPipelineBuilderExtensions.cs
@@ -23,6 +23,7 @@ public static IDiffingStrategyCollection IgnoreDiffAttributes(this IDiffingStrat
     public static IDiffingStrategyCollection AddAttributeNameMatcher(this IDiffingStrategyCollection builder)
     {
         builder.AddMatcher(AttributeNameMatcher.Match, StrategyType.Generalized);
+        builder.AddMatcher(IgnoreAttributeMatcher.Match, StrategyType.Generalized);
         return builder;
     }
 
diff --git a/src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeMatcher.cs b/src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeMatcher.cs
new file mode 100644
index 0000000..d079042
--- /dev/null
+++ b/src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeMatcher.cs
@@ -0,0 +1,29 @@
+namespace AngleSharp.Diffing.Strategies.AttributeStrategies;
+
+/// <summary>
+/// Ignore Attribute matcher strategy.
+/// </summary>
+public static class IgnoreAttributeMatcher
+{
+    private const string DIFF_IGNORE_POSTFIX = ":ignore";
+
+    /// <summary>
+    /// Attribute name matcher strategy.
+    /// </summary>
+    public static IEnumerable<AttributeComparison> Match(IDiffContext context, SourceMap controlSources, SourceMap testSources)
+    {
+        if (controlSources is null)
+            throw new ArgumentNullException(nameof(controlSources));
+        if (testSources is null)
+            throw new ArgumentNullException(nameof(testSources));
+
+        foreach (var control in controlSources.GetUnmatched())
+        {
+            // An unmatched :ignore attribute can just be matched with itself if it isn't
+            // matched with a "test" attribute of the same name already.
+            // this means an ignored attribute is ignored even if it does not appear in the test html.
+            if (control.Attribute.Name.EndsWith(DIFF_IGNORE_POSTFIX, StringComparison.OrdinalIgnoreCase))
+                yield return new AttributeComparison(control, control);
+        }
+    }
+}
\ No newline at end of file

From 25975588e119f3fcb2b53ebf74bc065a6ee9bd8c Mon Sep 17 00:00:00 2001
From: RiRiSharp <github@ririsharp.nl>
Date: Sun, 14 Sep 2025 20:25:11 +0200
Subject: [PATCH 5/7] Fix Linux pipeline

---
 build.sh | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/build.sh b/build.sh
index c62ce5c..1f8df2e 100755
--- a/build.sh
+++ b/build.sh
@@ -20,6 +20,8 @@ DRYRUN=
 SHOW_VERSION=false
 SCRIPT_ARGUMENTS=()
 
+sudo apt install mono-devel # ubuntu-latest does not come with mono pre-installed anymore.
+
 # Parse arguments.
 for i in "$@"; do
     case $1 in

From 082c0d66b77590b236a017d6dc92def9427b7441 Mon Sep 17 00:00:00 2001
From: RiRiSharp <github@ririsharp.nl>
Date: Sun, 14 Sep 2025 20:36:21 +0200
Subject: [PATCH 6/7] Create IgnoreAttributeStrategy and make
 IgnoreAttributeComparer obsolete

---
 .../IgnoreAttributeComparerTest.cs            |  8 ++++----
 ...iffingStrategyPipelineBuilderExtensions.cs |  4 ++--
 .../IgnoreAttributeComparer.cs                |  7 ++++---
 ...eMatcher.cs => IgnoreAttributeStrategy.cs} | 20 ++++++++++++++++++-
 4 files changed, 29 insertions(+), 10 deletions(-)
 rename src/AngleSharp.Diffing/Strategies/AttributeStrategies/{IgnoreAttributeMatcher.cs => IgnoreAttributeStrategy.cs} (65%)

diff --git a/src/AngleSharp.Diffing.Tests/Strategies/AttributeStrategies/IgnoreAttributeComparerTest.cs b/src/AngleSharp.Diffing.Tests/Strategies/AttributeStrategies/IgnoreAttributeComparerTest.cs
index a59efc3..34bb922 100644
--- a/src/AngleSharp.Diffing.Tests/Strategies/AttributeStrategies/IgnoreAttributeComparerTest.cs
+++ b/src/AngleSharp.Diffing.Tests/Strategies/AttributeStrategies/IgnoreAttributeComparerTest.cs
@@ -17,7 +17,7 @@ public void Test000(CompareResult currentResult)
             @"<p foo=""bar""></p>", "foo"
         );
 
-        IgnoreAttributeComparer
+        IgnoreAttributeStrategy
             .Compare(comparison, currentResult)
             .ShouldBe(currentResult);
     }
@@ -30,8 +30,8 @@ public void Test003()
             @"<p foo=""bar""></p>", "foo"
         );
 
-        IgnoreAttributeComparer.Compare(comparison, CompareResult.Different).ShouldBe(CompareResult.Different);
-        IgnoreAttributeComparer.Compare(comparison, CompareResult.Same).ShouldBe(CompareResult.Same);
+        IgnoreAttributeStrategy.Compare(comparison, CompareResult.Different).ShouldBe(CompareResult.Different);
+        IgnoreAttributeStrategy.Compare(comparison, CompareResult.Same).ShouldBe(CompareResult.Same);
     }
 
     [Fact(DisplayName = "When a attribute does contain have the ':ignore' postfix, Same is returned")]
@@ -42,6 +42,6 @@ public void Test004()
             @"<p foo=""baz""></p>", "foo"
         );
 
-        IgnoreAttributeComparer.Compare(comparison, CompareResult.Unknown).ShouldBe(CompareResult.Same);
+        IgnoreAttributeStrategy.Compare(comparison, CompareResult.Unknown).ShouldBe(CompareResult.Same);
     }
 }
diff --git a/src/AngleSharp.Diffing/Strategies/AttributeStrategies/DiffingStrategyPipelineBuilderExtensions.cs b/src/AngleSharp.Diffing/Strategies/AttributeStrategies/DiffingStrategyPipelineBuilderExtensions.cs
index 18f619b..ca9f18d 100644
--- a/src/AngleSharp.Diffing/Strategies/AttributeStrategies/DiffingStrategyPipelineBuilderExtensions.cs
+++ b/src/AngleSharp.Diffing/Strategies/AttributeStrategies/DiffingStrategyPipelineBuilderExtensions.cs
@@ -23,7 +23,7 @@ public static IDiffingStrategyCollection IgnoreDiffAttributes(this IDiffingStrat
     public static IDiffingStrategyCollection AddAttributeNameMatcher(this IDiffingStrategyCollection builder)
     {
         builder.AddMatcher(AttributeNameMatcher.Match, StrategyType.Generalized);
-        builder.AddMatcher(IgnoreAttributeMatcher.Match, StrategyType.Generalized);
+        builder.AddMatcher(IgnoreAttributeStrategy.Match, StrategyType.Generalized);
         return builder;
     }
 
@@ -34,7 +34,7 @@ public static IDiffingStrategyCollection AddAttributeComparer(this IDiffingStrat
     {
         builder.AddMatcher(PostfixedAttributeMatcher.Match, StrategyType.Specialized);
         builder.AddComparer(AttributeComparer.Compare, StrategyType.Generalized);
-        builder.AddComparer(IgnoreAttributeComparer.Compare, StrategyType.Specialized);
+        builder.AddComparer(IgnoreAttributeStrategy.Compare, StrategyType.Specialized);
         return builder;
     }
 
diff --git a/src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeComparer.cs b/src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeComparer.cs
index 087ca08..eb42457 100644
--- a/src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeComparer.cs
+++ b/src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeComparer.cs
@@ -3,6 +3,7 @@
 /// <summary>
 /// Represents the ignore attribute comparer.
 /// </summary>
+[Obsolete("Has been moved to IgnoreAttributeStrategy")]
 public static class IgnoreAttributeComparer
 {
     private const string DIFF_IGNORE_POSTFIX = ":ignore";
@@ -20,8 +21,8 @@ public static CompareResult Compare(in AttributeComparison comparison, CompareRe
             : currentDecision;
     }
 
-    public static bool IsIgnoreAttribute(IAttr source)
+    private static bool IsIgnoreAttribute(IAttr source)
     {
-        return source.Name.EndsWith(DIFF_IGNORE_POSTFIX,  StringComparison.OrdinalIgnoreCase);
+        return source.Name.EndsWith(DIFF_IGNORE_POSTFIX, StringComparison.OrdinalIgnoreCase);
     }
-}
+}
\ No newline at end of file
diff --git a/src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeMatcher.cs b/src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeStrategy.cs
similarity index 65%
rename from src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeMatcher.cs
rename to src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeStrategy.cs
index d079042..84d24b6 100644
--- a/src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeMatcher.cs
+++ b/src/AngleSharp.Diffing/Strategies/AttributeStrategies/IgnoreAttributeStrategy.cs
@@ -3,10 +3,23 @@
 /// <summary>
 /// Ignore Attribute matcher strategy.
 /// </summary>
-public static class IgnoreAttributeMatcher
+public static class IgnoreAttributeStrategy
 {
     private const string DIFF_IGNORE_POSTFIX = ":ignore";
 
+    /// <summary>
+    /// The ignore attribute comparer.
+    /// </summary>
+    public static CompareResult Compare(in AttributeComparison comparison, CompareResult currentDecision)
+    {
+        if (currentDecision.IsSameOrSkip)
+            return currentDecision;
+
+        return IsIgnoreAttribute(comparison.Control.Attribute)
+            ? CompareResult.Same
+            : currentDecision;
+    }
+
     /// <summary>
     /// Attribute name matcher strategy.
     /// </summary>
@@ -26,4 +39,9 @@ public static IEnumerable<AttributeComparison> Match(IDiffContext context, Sourc
                 yield return new AttributeComparison(control, control);
         }
     }
+
+    private static bool IsIgnoreAttribute(IAttr source)
+    {
+        return source.Name.EndsWith(DIFF_IGNORE_POSTFIX,  StringComparison.OrdinalIgnoreCase);
+    }
 }
\ No newline at end of file

From afee48a97322591f5a6318dbc7aef77e7e93c36a Mon Sep 17 00:00:00 2001
From: RiRiSharp <github@ririsharp.nl>
Date: Mon, 15 Sep 2025 10:31:53 +0200
Subject: [PATCH 7/7] Revert "Fix Linux pipeline"

This reverts commit 25975588e119f3fcb2b53ebf74bc065a6ee9bd8c.
---
 build.sh | 2 --
 1 file changed, 2 deletions(-)

diff --git a/build.sh b/build.sh
index 1f8df2e..c62ce5c 100755
--- a/build.sh
+++ b/build.sh
@@ -20,8 +20,6 @@ DRYRUN=
 SHOW_VERSION=false
 SCRIPT_ARGUMENTS=()
 
-sudo apt install mono-devel # ubuntu-latest does not come with mono pre-installed anymore.
-
 # Parse arguments.
 for i in "$@"; do
     case $1 in