feat: add unit tests

t/03-formatting.t

@@ -0,0 +1,65 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+
+use Test::More tests => 11;
+use MarkdownParser;
+
+my $parser = MarkdownParser->new();
+
+is(
+    $parser->parse("**bold text**"),
+    "<p><strong>bold text</strong></p>\n",
+    "Bold with **"
+);
+is(
+    $parser->parse("__bold text__"),
+    "<p><strong>bold text</strong></p>\n",
+    "Bold with __"
+);
+is(
+    $parser->parse("*italic text*"),
+    "<p><em>italic text</em></p>\n",
+    "Italic with *"
+);
+is(
+    $parser->parse("_italic text_"),
+    "<p><em>italic text</em></p>\n",
+    "Italic with _"
+);
+is(
+    $parser->parse("**bold** and *italic*"),
+    "<p><strong>bold</strong> and <em>italic</em></p>\n",
+    "Bold and italic together"
+);
+is(
+    $parser->parse("Text with **bold** in middle"),
+    "<p>Text with <strong>bold</strong> in middle</p>\n",
+    "Bold in middle of text"
+);
+is(
+    $parser->parse("Text with *italic* in middle"),
+    "<p>Text with <em>italic</em> in middle</p>\n",
+    "Italic in middle of text"
+);
+is(
+    $parser->parse("**bold** *italic* **bold again**"),
+"<p><strong>bold</strong> <em>italic</em> <strong>bold again</strong></p>\n",
+    "Multiple formatting"
+);
+is(
+    $parser->parse("***bold text***"),
+    "<p><strong>bold text</strong></p>\n",
+    "Bold with ***"
+);
+is(
+    $parser->parse("**bold *italic* bold**"),
+    "<p><strong>bold <em>italic</em> bold</strong></p>\n",
+    "Nested formatting"
+);
+is(
+    $parser->parse("___bold text___"),
+    "<p><strong>bold text</strong></p>\n",
+    "Bold with ___"
+);
+