feat: add unit tests

t/04-links-images.t

@@ -0,0 +1,44 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+
+use Test::More tests => 8;
+use MarkdownParser;
+
+my $parser = MarkdownParser->new();
+
+is(
+    $parser->parse("[link text](http://example.com)"),
+    "<p><a href=\"http://example.com\">link text</a></p>\n",
+    "Simple link"
+);
+is(
+    $parser->parse("[link with spaces](https://example.com/path)"),
+    "<p><a href=\"https://example.com/path\">link with spaces</a></p>\n",
+    "Link with path"
+);
+is(
+    $parser->parse("![alt text](image.png)"),
+    "<p><img src=\"image.png\" alt=\"alt text\"></p>\n",
+    "Simple image"
+);
+is(
+    $parser->parse("![alt with spaces](http://example.com/image.jpg)"),
+"<p><img src=\"http://example.com/image.jpg\" alt=\"alt with spaces\"></p>\n",
+    "Image with URL"
+);
+is(
+    $parser->parse("[Click me](javascript:alert('XSS'))"),
+    "<p>Click me</p>\n",
+    "JavaScript protocol blocked in links"
+);
+is(
+    $parser->parse("[Click me](data:text/html,<script>alert('XSS')</script>)"),
+    "<p>Click me</p>\n",
+    "Data protocol blocked in links"
+);
+is( $parser->parse("![Image](javascript:alert('XSS'))"),
+    "<p>Image</p>\n", "JavaScript protocol blocked in images" );
+is( $parser->parse("![Image](file:///etc/passwd)"),
+    "<p>Image</p>\n", "File protocol blocked in images" );
+