Fix bug with empty lists

src/Html2Markdown/Replacement/HtmlParser.cs

@@ -68,6 +68,8 @@ private static string ReplaceList(string html)
 			}
 			markdownList.Add($"{listPrefix}{finalList}");
 		});
+
+		if (markdownList.Count == 0) return string.Empty;
 
 		//If a new line is already ending the markdown item, then we don't need to add another one
 		return Environment.NewLine + Environment.NewLine + markdownList.Aggregate((current, item) =>  current.EndsWith(Environment.NewLine) ? current + item : current + Environment.NewLine + item) + Environment.NewLine + Environment.NewLine;

test/Html2Markdown.Test/CommonMarkSchemeConverterTest.Convert_WhenThereIsAnEmptyList_ThenRemoveTheList.verified.txt

@@ -0,0 +1 @@
+emptyString

test/Html2Markdown.Test/MarkdownSchemeConverterTest.Convert_WhenThereIsAnEmptyList_ThenRemoveTheList.verified.txt

@@ -0,0 +1 @@
+emptyString

test/Html2Markdown.Test/MarkdownSchemeConverterTest.cs

@@ -660,6 +660,15 @@ public Task Convert_WhenThereAreMultipleUnorderedLists_ThenReplaceWithMarkdownLi
 
 		return CheckConversion(html);
 	}
+
+	// See issue https://github.com/baynezy/Html2Markdown/issues/109
+	[Test]
+	public Task Convert_WhenThereIsAnEmptyList_ThenRemoveTheList()
+	{
+		const string html = "<ul><li></li></ul>";
+
+		return CheckConversion(html);
+	}
 
 	#endregion