Improve CQ1

src/Markdig/Extensions/Footnotes/FootnoteParser.cs

@@ -2,6 +2,8 @@
 // This file is licensed under the BSD-Clause 2 license. 
 // See the license.txt file in the project root for more information.
 
+using System;
+
 using Markdig.Helpers;
 using Markdig.Parsers;
 using Markdig.Syntax;
@@ -41,7 +43,7 @@ private BlockState TryOpen(BlockProcessor processor, bool isContinue)
 
             var saved = processor.Column;
             int start = processor.Start;
-            if (!LinkHelper.TryParseLabel(ref processor.Line, false, out string? label, out SourceSpan labelSpan) || !label.StartsWith("^") || processor.CurrentChar != ':')
+            if (!LinkHelper.TryParseLabel(ref processor.Line, false, out string? label, out SourceSpan labelSpan) || !label.StartsWith("^", StringComparison.Ordinal) || processor.CurrentChar != ':')
             {
                 processor.GoToColumn(saved);
                 return BlockState.None;

src/Markdig/Extensions/MediaLinks/HostProviderBuilder.cs

@@ -92,16 +92,16 @@ private static string[] SplitQuery(Uri uri)
             }
             var queryParams = SplitQuery(uri);
             return BuildYouTubeIframeUrl(
-                queryParams.FirstOrDefault(p => p.StartsWith("v="))?.Substring(2),
-                queryParams.FirstOrDefault(p => p.StartsWith("t="))?.Substring(2)
+                queryParams.FirstOrDefault(p => p.StartsWith("v=", StringComparison.Ordinal))?.Substring(2),
+                queryParams.FirstOrDefault(p => p.StartsWith("t=", StringComparison.Ordinal))?.Substring(2)
             );
         }
 
         private static string? YouTubeShortened(Uri uri)
         {
             return BuildYouTubeIframeUrl(
                 uri.AbsolutePath.Substring(1),
-                SplitQuery(uri).FirstOrDefault(p => p.StartsWith("t="))?.Substring(2)
+                SplitQuery(uri).FirstOrDefault(p => p.StartsWith("t=", StringComparison.Ordinal))?.Substring(2)
             );
         }
 
@@ -135,7 +135,7 @@ private static string[] SplitQuery(Uri uri)
             string? trackKeyword = items.Skip(2).FirstOrDefault();
             string? trackId = items.Skip(3).FirstOrDefault();
 
-            if (albumKeyword != "album" || albumId is null || trackKeyword != "track" || trackId is null)
+            if (albumKeyword is not "album" || albumId is null || trackKeyword is not "track" || trackId is null)
             {
                 return null;
             }

src/Markdig/Extensions/MediaLinks/MediaLinkExtension.cs

@@ -57,7 +57,7 @@ private bool TryLinkInlineRenderer(HtmlRenderer renderer, LinkInline linkInline)
             {
                 // see https://tools.ietf.org/html/rfc3986#section-4.2
                 // since relative uri doesn't support many properties, "http" is used as a placeholder here.
-                if (linkInline.Url.StartsWith("//") && Uri.TryCreate("http:" + linkInline.Url, UriKind.Absolute, out uri))
+                if (linkInline.Url.StartsWith("//", StringComparison.Ordinal) && Uri.TryCreate("http:" + linkInline.Url, UriKind.Absolute, out uri))
                 {
                     isSchemaRelative = true;
                 }
@@ -101,7 +101,7 @@ private bool TryGuessAudioVideoFile(Uri uri, bool isSchemaRelative, HtmlRenderer
                 Options.ExtensionToMimeType.TryGetValue(path.Substring(lastDot), out string? mimeType))
             {
                 var htmlAttributes = GetHtmlAttributes(linkInline);
-                var isAudio = mimeType.StartsWith("audio");
+                var isAudio = mimeType.StartsWith("audio", StringComparison.Ordinal);
                 var tagType = isAudio ? "audio" : "video";
 
                 renderer.Write($"<{tagType}");

src/Markdig/Extensions/ReferralLinks/ReferralLinksExtension.cs

@@ -9,14 +9,14 @@
 
 namespace Markdig.Extensions.ReferralLinks
 {
-    public class ReferralLinksExtension : IMarkdownExtension
+    public sealed class ReferralLinksExtension : IMarkdownExtension
     {
         public ReferralLinksExtension(string[] rels)
         {
-            Rels = rels?.ToList();
+            Rels = rels.ToList();
         }
 
-        public List<string>? Rels { get; }
+        public List<string> Rels { get; }
 
         public void Setup(MarkdownPipelineBuilder pipeline)
         {

src/Markdig/Extensions/SelfPipeline/SelfPipelineExtension.cs

@@ -86,7 +86,7 @@ public MarkdownPipeline CreatePipelineFromInput(string inputText)
                 var endOfTag = inputText.IndexOf("-->", optionStart, StringComparison.OrdinalIgnoreCase);
                 if (endOfTag >= 0)
                 {
-                    defaultConfig = inputText.Substring(optionStart, endOfTag - optionStart).Trim();
+                    defaultConfig = inputText.AsSpan(optionStart, endOfTag - optionStart).Trim().ToString();
                 }
             }
 

src/Markdig/Helpers/CompactPrefixTree.cs

@@ -519,7 +519,7 @@ private bool TryInsert(in KeyValuePair<string, TValue> pair, InsertionBehavior b
                                 Debug.Assert(key.Length != previousKey.Length);
                                 if (previousKey.Length < key.Length) // If the input was sorted, this should be hit
                                 {
-                                    Debug.Assert(key.StartsWith(previousKey));
+                                    Debug.Assert(key.StartsWith(previousKey, StringComparison.Ordinal));
                                     node.ChildChar = key[i];
                                     node.MatchIndex = previousMatchIndex;
                                     EnsureTreeCapacity(TreeSize + 1);
@@ -533,7 +533,7 @@ private bool TryInsert(in KeyValuePair<string, TValue> pair, InsertionBehavior b
                                 else // if key.Length < previousKey.Length
                                 {
                                     Debug.Assert(key.Length < previousKey.Length);
-                                    Debug.Assert(previousKey.StartsWith(key));
+                                    Debug.Assert(previousKey.StartsWith(key, StringComparison.Ordinal));
                                     node.ChildChar = previousKey[i];
                                     node.MatchIndex = Count;
                                     EnsureTreeCapacity(TreeSize + 1);
@@ -583,7 +583,7 @@ private bool TryInsert(in KeyValuePair<string, TValue> pair, InsertionBehavior b
                         else
                         {
                             // This node has a child char, therefore we either don't have a match attached or that match is simply a prefix of the current key
-                            Debug.Assert(node.MatchIndex == -1 || key.StartsWith(_matches[node.MatchIndex].Key));
+                            Debug.Assert(node.MatchIndex == -1 || key.StartsWith(_matches[node.MatchIndex].Key, StringComparison.Ordinal));
 
                             // Set this pair as the current node's first element in the Children list
                             node.Children = _childrenIndex;
@@ -641,7 +641,7 @@ private bool TryInsert(in KeyValuePair<string, TValue> pair, InsertionBehavior b
                         // It's not a duplicate but shares key.Length characters, therefore it's longer
                         // This will never occur if the input was sorted
                         Debug.Assert(previousMatch.Key.Length > key.Length);
-                        Debug.Assert(previousMatch.Key.StartsWith(key));
+                        Debug.Assert(previousMatch.Key.StartsWith(key, StringComparison.Ordinal));
                         Debug.Assert(node.ChildChar == 0 && node.Children == -1);
 
                         // It is a leaf node

src/Markdig/Markdig.targets

@@ -6,6 +6,9 @@
     <NeutralLanguage>en-US</NeutralLanguage>
     <VersionPrefix>0.23.0</VersionPrefix>
     <Authors>Alexandre Mutel</Authors>
+
+    <!-- Markdig.Wpf needs support for net452 which is supported by Microsoft until January 10, 2023 -->
+    <!-- The decision to continue support for this target is documented in https://github.com/xoofx/markdig/pull/466 -->
     <TargetFrameworks>net452;netstandard2.0;netstandard2.1;netcoreapp2.1;netcoreapp3.1</TargetFrameworks>
     <PackageTags>Markdown CommonMark md html md2html</PackageTags>
     <PackageReleaseNotes>https://github.com/lunet-io/markdig/blob/master/changelog.md</PackageReleaseNotes>

src/Markdig/MarkdownExtensions.cs

@@ -452,6 +452,7 @@ public static MarkdownPipelineBuilder UseEmojiAndSmiley(this MarkdownPipelineBui
             }
             return pipeline;
         }
+
         /// <summary>
         /// Add rel=nofollow to all links rendered to HTML.
         /// </summary>
@@ -463,20 +464,23 @@ public static MarkdownPipelineBuilder UseNoFollowLinks(this MarkdownPipelineBuil
             return pipeline.UseReferralLinks("nofollow");
         }
 
-        public static MarkdownPipelineBuilder UseReferralLinks(this MarkdownPipelineBuilder pipeline, params string[] rels)
+        public static MarkdownPipelineBuilder UseReferralLinks(this MarkdownPipelineBuilder pipeline, params string[]? rels)
         {
-            if (!pipeline.Extensions.Contains<ReferralLinksExtension>())
+            rels ??= ArrayHelper.Empty<string>();
+
+            var extension = pipeline.Extensions.Find<ReferralLinksExtension>();
+
+            if (extension is null)
             {
                 pipeline.Extensions.Add(new ReferralLinksExtension(rels));
             }
             else
             {
-                var referralLinksExtension = pipeline.Extensions.Find<ReferralLinksExtension>();
-                foreach(string rel in rels)
+                foreach (string rel in rels)
                 {
-                    if (!referralLinksExtension.Rels.Contains(rel))
+                    if (!extension.Rels.Contains(rel))
                     {
-                        referralLinksExtension.Rels.Add(rel);
+                        extension.Rels.Add(rel);
                     }
                 }
             }

src/Markdig/Parsers/FencedBlockParserBase.cs

@@ -234,7 +234,7 @@ public static bool DefaultInfoParser(BlockProcessor state, ref StringSlice line,
                     }
                 }
 
-                argString = line.Text.Substring(firstSpace, line.End - firstSpace + 1).Trim();
+                argString = line.Text.AsSpan(firstSpace, line.End - firstSpace + 1).Trim().ToString();
             }
             else
             {

src/Markdig/Parsers/ListBlockParser.cs

@@ -262,7 +262,7 @@ private BlockState TryParseListItem(BlockProcessor state, Block? block)
             if ((block ?? state.LastBlock) is ParagraphBlock previousParagraph)
             {
                 if (state.IsBlankLine ||
-                    state.IsOpen(previousParagraph) && listInfo.BulletType == '1' && listInfo.OrderedStart != "1")
+                    state.IsOpen(previousParagraph) && listInfo.BulletType == '1' && listInfo.OrderedStart is not "1")
                 {
                     state.GoToColumn(initColumn);
                     state.TriviaStart = savedTriviaStart; // restore changed TriviaStart state

src/Markdig/Renderers/Html/CodeBlockRenderer.cs

@@ -47,7 +47,7 @@ protected override void Write(HtmlRenderer renderer, CodeBlock obj)
                 {
                     renderer.Write("<div")
                             .WriteAttributes(obj.TryGetAttributes(),
-                                cls => cls.StartsWith(infoPrefix) ? cls.Substring(infoPrefix.Length) : cls)
+                                cls => cls.StartsWith(infoPrefix, StringComparison.Ordinal) ? cls.Substring(infoPrefix.Length) : cls)
                             .Write(">");
                 }
 

src/Markdig/Renderers/Html/ListRenderer.cs

@@ -25,7 +25,7 @@ protected override void Write(HtmlRenderer renderer, ListBlock listBlock)
                         renderer.Write(" type=\"").Write(listBlock.BulletType).Write("\"");
                     }
 
-                    if (listBlock.OrderedStart != null && (listBlock.OrderedStart != "1"))
+                    if (listBlock.OrderedStart != null && (listBlock.OrderedStart is not "1"))
                     {
                         renderer.Write(" start=\"").Write(listBlock.OrderedStart).Write("\"");
                     }

src/Markdig/Renderers/Roundtrip/CodeBlockRenderer.cs

@@ -67,11 +67,13 @@ protected override void Write(RoundtripRenderer renderer, CodeBlock obj)
             }
             else
             {
-                var indents = new List<string>();
-                foreach (var cbl in obj.CodeBlockLines)
+                var indents = new string[obj.CodeBlockLines.Count];
+
+                for (int i = 0; i < obj.CodeBlockLines.Count; i++)
                 {
-                    indents.Add(cbl.TriviaBefore.ToString());
+                    indents[i] = obj.CodeBlockLines[i].TriviaBefore.ToString();
                 }
+
                 renderer.PushIndent(indents);
                 WriteLeafRawLines(renderer, obj);
                 renderer.PopIndent();

src/Markdig/Renderers/Roundtrip/ListRenderer.cs

@@ -28,7 +28,7 @@ protected override void Write(RoundtripRenderer renderer, ListBlock listBlock)
                     var bws = listItem.TriviaBefore.ToString();
                     var bullet = listItem.SourceBullet.ToString();
                     var delimiter = listBlock.OrderedDelimiter;
-                    renderer.PushIndent(new List<string> { $@"{bws}{bullet}{delimiter}" });
+                    renderer.PushIndent(new string[] { $"{bws}{bullet}{delimiter}" });
                     renderer.WriteChildren(listItem);
                     renderer.RenderLinesAfter(listItem);
                 }
@@ -45,7 +45,7 @@ protected override void Write(RoundtripRenderer renderer, ListBlock listBlock)
                     char bullet = listBlock.BulletType;
                     StringSlice aws = listItem.TriviaAfter;
 
-                    renderer.PushIndent(new List<string> { $@"{bws}{bullet}{aws}" });
+                    renderer.PushIndent(new string[] { $"{bws}{bullet}{aws}" });
                     if (listItem.Count == 0)
                     {
                         renderer.Write(""); // trigger writing of indent

src/Markdig/Renderers/Roundtrip/QuoteBlockRenderer.cs

@@ -18,14 +18,15 @@ protected override void Write(RoundtripRenderer renderer, QuoteBlock quoteBlock)
             renderer.RenderLinesBefore(quoteBlock);
             renderer.Write(quoteBlock.TriviaBefore);
 
-            var indents = new List<string>();
-            foreach (var quoteLine in quoteBlock.QuoteLines)
+            var indents = new string[quoteBlock.QuoteLines.Count];
+            for (int i = 0; i < quoteBlock.QuoteLines.Count; i++)
             {
+                var quoteLine = quoteBlock.QuoteLines[i];
                 var wsb = quoteLine.TriviaBefore.ToString();
                 var quoteChar = quoteLine.QuoteChar ? ">" : "";
                 var spaceAfterQuoteChar = quoteLine.HasSpaceAfterQuoteChar ? " " : "";
                 var wsa = quoteLine.TriviaAfter.ToString();
-                indents.Add(wsb + quoteChar + spaceAfterQuoteChar + wsa);
+                indents[i] = (wsb + quoteChar + spaceAfterQuoteChar + wsa);
             }
             bool noChildren = false;
             if (quoteBlock.Count == 0)

src/Markdig/Renderers/TextRendererBase.cs

@@ -71,19 +71,21 @@ public override object Render(MarkdownObject markdownObject)
     /// <seealso cref="RendererBase" />
     public abstract class TextRendererBase<T> : TextRendererBase where T : TextRendererBase<T>
     {
-        private class Indent
+        private sealed class Indent
         {
             private readonly string? _constant;
-            private readonly Queue<string>? _lineSpecific;
+            private readonly string[]? _lines;
+
+            private int position = 0;
 
             internal Indent(string constant)
             {
                 _constant = constant;
             }
 
-            internal Indent(IEnumerable<string> lineSpecific)
+            internal Indent(string[] lineSpecific)
             {
-                _lineSpecific = new Queue<string>(lineSpecific);
+                _lines = lineSpecific;
             }
 
             internal string Next()
@@ -93,10 +95,10 @@ internal string Next()
                     return _constant;
                 }
 
-                //if (_lineSpecific.Count == 0) throw new Exception("Indents empty");
-                if (_lineSpecific!.Count == 0) return string.Empty;
-                var next = _lineSpecific.Dequeue();
-                return next;
+                //if (_lines.Count == 0) throw new Exception("Indents empty");
+                if (position == _lines!.Length) return string.Empty;
+
+                return _lines![position++];             
             }
         }
 
@@ -160,7 +162,7 @@ public void PushIndent(string indent)
             indents.Add(new Indent(indent));
         }
 
-        public void PushIndent(IEnumerable<string> lineSpecific)
+        public void PushIndent(string[] lineSpecific)
         {
             if (indents is null) ThrowHelper.ArgumentNullException(nameof(indents));
             indents.Add(new Indent(lineSpecific));