Add support for "Github Flavored Markdown Task Lists" (#405)

* Added support for check lists (github flavored markdowns only)
* Updated readme
* Clean up

Author: Hasan-75

README.md

@@ -97,7 +97,7 @@ var converter = new ReverseMarkdown.Converter(config);
 
 * Supports all the established html tags like h1, h2, h3, h4, h5, h6, p, em, strong, i, b, blockquote, code, img, a, hr, li, ol, ul, table, tr, th, td, br
 * Can deal with nested lists
-* Github Flavoured Markdown conversion supported for br, pre and table. Use `var config = new ReverseMarkdown.Config(githubFlavoured:true);`. By default table will always be converted to Github flavored markdown immaterial of this flag.
+* Github Flavoured Markdown conversion supported for br, pre, tasklists and table. Use `var config = new ReverseMarkdown.Config(githubFlavoured:true);`. By default table will always be converted to Github flavored markdown immaterial of this flag.
 
 ## Acknowledgements
 This library's initial implementation ideas were from the Ruby based Html to Markdown converter [ xijo/reverse_markdown](https://github.com/xijo/reverse_markdown).

README.source.md

@@ -91,7 +91,7 @@ var converter = new ReverseMarkdown.Converter(config);
 
 * Supports all the established html tags like h1, h2, h3, h4, h5, h6, p, em, strong, i, b, blockquote, code, img, a, hr, li, ol, ul, table, tr, th, td, br
 * Supports nested lists
-* Github Flavoured Markdown conversion supported for br, pre and table. Use `var config = new ReverseMarkdown.Config(githubFlavoured:true);`. By default the table will always be converted to Github flavored markdown immaterial of this flag.
+* Github Flavoured Markdown conversion supported for br, pre, tasklists and table. Use `var config = new ReverseMarkdown.Config(githubFlavoured:true);`. By default the table will always be converted to Github flavored markdown immaterial of this flag.
 
 ## Acknowledgements
 This library's initial implementation ideas were from the Ruby based Html to Markdown converter [ xijo/reverse_markdown](https://github.com/xijo/reverse_markdown).

src/ReverseMarkdown.Test/ConverterTests.WhenThereIsInputListWithGithubFlavoredDisabled_ThenConvertToTypicalMarkdownList.verified.md

@@ -0,0 +1,2 @@
+- <input type="checkbox" disabled> Unchecked
+- <input type="checkbox" checked> Checked

src/ReverseMarkdown.Test/ConverterTests.WhenThereIsInputListWithGithubFlavoredEnabled_ThenConvertToMarkdownCheckList.verified.md

@@ -0,0 +1,2 @@
+- [ ] Unchecked
+- [x] Checked

src/ReverseMarkdown.Test/ConverterTests.cs

@@ -541,6 +541,32 @@ public Task WhenThereIsUnorderedListAndBulletIsAsterisk_ThenConvertToMarkdownLis
             return CheckConversion(html, new Config {ListBulletChar = '*'});
         }
 
+        [Fact]
+        public Task WhenThereIsInputListWithGithubFlavoredEnabled_ThenConvertToMarkdownCheckList()
+        {
+            var html = "<ul><li><input type=\"checkbox\" disabled> Unchecked</li><li><input type=\"checkbox\" checked> Checked</li></ul>";
+
+            var config = new Config
+            {
+                GithubFlavored = true,
+            };
+
+            return CheckConversion(html, config);
+        }
+
+        [Fact]
+        public Task WhenThereIsInputListWithGithubFlavoredDisabled_ThenConvertToTypicalMarkdownList()
+        {
+            var html = "<ul><li><input type=\"checkbox\" disabled> Unchecked</li><li><input type=\"checkbox\" checked> Checked</li></ul>";
+
+            var config = new Config
+            {
+                GithubFlavored = false,
+            };
+
+            return CheckConversion(html, config);
+        }
+
         [Fact]
         public Task WhenThereIsOrderedList_ThenConvertToMarkdownList()
         {

src/ReverseMarkdown/Converters/Li.cs

@@ -1,7 +1,7 @@
-using System;
+using HtmlAgilityPack;
+using System;
 using System.Linq;
-
-using HtmlAgilityPack;
+using System.Text;
 
 namespace ReverseMarkdown.Converters
 {
@@ -25,7 +25,7 @@ public override string Convert(HtmlNode node)
                 }
             }
 
-            var content = TreatChildren(node);
+            var content = ContentFor(node);
             var indentation = IndentationFor(node, true);
             var prefix = PrefixFor(node);
 
@@ -45,5 +45,27 @@ private string PrefixFor(HtmlNode node)
                 return $"{Converter.Config.ListBulletChar} ";
             }
         }
+
+        private string ContentFor(HtmlNode node)
+        {
+            if (!Converter.Config.GithubFlavored)
+                return TreatChildren(node);
+
+            var content = new StringBuilder();
+
+            if (node.FirstChild is HtmlNode childNode
+                && childNode.Name == "input"
+                && childNode.GetAttributeValue("type", "").Equals("checkbox", StringComparison.OrdinalIgnoreCase))
+            {
+                content.Append(childNode.Attributes.Contains("checked")
+                    ? $"[x]"
+                    : $"[ ]");
+
+                node.RemoveChild(childNode);
+            }
+
+            content.Append(TreatChildren(node));
+            return content.ToString();
+        }
     }
 }