Add tests for MarkdownParser class

glazed-donut.Tests/MarkdownParserTests.cs

@@ -0,0 +1,53 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+using GlazedDonut.FileParsing.Parsing;
+using Xunit;
+
+namespace glazed_donut.Tests
+{
+    public class MarkdownParserTests
+    {
+        [Fact]
+        public void ThrowException_WhenStreamIsNull()
+        {
+            ArgumentNullException e = Assert.Throws<ArgumentNullException>(() => {
+                var parser = new MarkdownParser(null);
+            });
+
+            Assert.NotNull(e);
+        }
+
+        [Fact]
+        public void ReturnEmptyParagraph_WhenStreamIsEmpty()
+        {
+            var str = "";
+            var stream = new MemoryStream(Encoding.UTF8.GetBytes(str));
+            var parser = new MarkdownParser(stream);
+
+            var htmlString = parser.Parse();
+
+            Assert.Equal("", htmlString); 
+        }
+
+        [Theory, MemberData(nameof(ValidInputStringData))]
+        public void ReturnHtmlString_WhenParagraphIsValid(string input, string expectedHtml)
+        {
+            var stream = new MemoryStream(Encoding.UTF8.GetBytes(input));
+            var parser = new MarkdownParser(stream);
+
+            var htmlString = parser.Parse();
+
+            Assert.Equal(expectedHtml, htmlString);
+        }
+
+        public static IEnumerable<object[]> ValidInputStringData =>
+            new List<object[]>
+            { 
+                new object[] { "Markdown", "<p>Markdown</p>\n" },
+                new object[] { "# Markdown", "<h1>Markdown</h1>\n" },
+                new object[] { "---", "<hr>" }
+            };
+    }
+}

glazed-donut/FileParsing/Parsing/MarkdownParser.cs

@@ -70,7 +70,7 @@ private string ProduceHtmlString(IEnumerable<string> paragraphs)
             {
                 if (IsHeading(p))
                 {
-                    htmlString += $"<h1>{p.Replace("\n", " ").Replace("#", string.Empty)}</h1>\n";
+                    htmlString += $"<h1>{p.Replace("#", string.Empty).Trim()}</h1>\n";
                 }
                 else if (IsHorizontalLine(p))
                 {