Refactor feeds to be more testable and to remove templates. (#36)

Move feed generation into generator classes and out of templates. Remove feed templates, since they don't have any UI elements.

Reviewed-on: https://gitea.subcultureofone.org/greg/tkr/pulls/36
Co-authored-by: Greg Sarjeant <greg@subcultureofone.org>
Co-committed-by: Greg Sarjeant <greg@subcultureofone.org>

.gitea/workflows/prerequisites.yaml

@@ -1,5 +1,5 @@
 name: Prerequisites Testing
-on: [push, pull_request]
+on: [pull_request]
 
 jobs:
   test-php-version-requirements:

src/Controller/FeedController/FeedController.php

@@ -1,34 +1,27 @@
 <?php
 class FeedController extends Controller {
-    private array $vars;
+    private $config;
-
+    private $ticks;
-    protected function render(string $templateFile, array $vars = []) {
-        $templatePath = TEMPLATES_DIR . "/" . $templateFile;
-
-        if (!file_exists($templatePath)) {
-            throw new RuntimeException("Template not found: $templatePath");
-        }
-
-        extract($vars, EXTR_SKIP);
-        include $templatePath;
-    }
 
     public function __construct(){
-        $config = ConfigModel::load();
+        $this->config = ConfigModel::load();
         $tickModel = new TickModel();
-        $ticks = iterator_to_array($tickModel->stream($config->itemsPerPage));
+        $this->ticks = iterator_to_array($tickModel->stream($this->config->itemsPerPage));
 
-        $this->vars = [
+        Log::debug("Loaded " . count($this->ticks) . " ticks for feeds");
-            'config' => $config,
-            'ticks' => $ticks,
-        ];
     }
 
     public function rss(){
-        $this->render("feed/rss.php", $this->vars);
+        $generator = new RssGenerator($this->config, $this->ticks);
+
+        header('Content-Type: ' . $generator->getContentType());
+        echo $generator->generate();
     }
 
     public function atom(){
-        $this->render("feed/atom.php", $this->vars);
+        $generator = new AtomGenerator($this->config, $this->ticks);
+
+        header('Content-Type: ' . $generator->getContentType());
+        echo $generator->generate();
     }
 }

src/Feed/AtomGenerator.php

@@ -0,0 +1,53 @@
+<?php
+class AtomGenerator extends FeedGenerator {
+    public function generate(): string {
+        $xml = '<?xml version="1.0" encoding="UTF-8"?>' . "\n";
+        $xml .= $this->buildFeed();
+        return $xml;
+    }
+
+    public function getContentType(): string {
+        return 'application/atom+xml; charset=utf-8';
+    }
+
+    private function buildFeed(): string {
+        $feedTitle = Util::escape_xml($this->config->siteTitle . " Atom Feed");
+        $siteUrl = Util::escape_xml(Util::buildUrl($this->config->baseUrl, $this->config->basePath));
+        $feedUrl = Util::escape_xml(Util::buildUrl($this->config->baseUrl, $this->config->basePath, 'feed/atom'));
+        $updated = date(DATE_ATOM, strtotime($this->ticks[0]['timestamp'] ?? 'now'));
+
+        ob_start();
+        ?>
+<feed xmlns="http://www.w3.org/2005/Atom">
+  <title><?php echo $feedTitle ?></title>
+  <link rel="self"
+        type="application/atom+xml"
+        title="<?php echo $feedTitle ?>"
+        href="<?php echo $feedUrl ?>" />
+  <link rel="alternate" href="<?php echo $siteUrl  ?>"/>
+  <updated><?php echo $updated ?></updated>
+  <id><?php echo $siteUrl ?></id>
+  <author>
+        <name><?= Util::escape_xml($this->config->siteTitle) ?></name>
+  </author>
+<?php foreach ($this->ticks as $tick):
+    // build the tick entry components
+    $tickPath = "tick/" . $tick['id'];
+    $tickUrl = Util::escape_xml($siteUrl . $tickPath);
+    $tickTime = date(DATE_ATOM, strtotime($tick['timestamp']));
+    $tickTitle = Util::escape_xml($tick['tick']);
+    $tickContent = Util::linkify($tickTitle);
+?>
+  <entry>
+    <title><?= $tickTitle ?></title>
+    <link href="<?= $tickUrl ?>"/>
+    <id><?= $tickUrl ?></id>
+    <updated><?= $tickTime ?></updated>
+    <content type="html"><?= $tickContent ?></content>
+  </entry>
+<?php endforeach; ?>
+</feed>
+<?php
+        return ob_get_clean();
+    }
+}

src/Feed/FeedGenerator.php

@@ -0,0 +1,24 @@
+<?php
+// Abstract base class for feeds.
+// Specific feeds (RSS, Atom, etc.) will inherit from this.
+// This will wrap the basic generator functionality.
+abstract class FeedGenerator {
+    protected $config;
+    protected $ticks;
+
+    public function __construct(ConfigModel $config, array $ticks) {
+        $this->config = $config;
+        $this->ticks = $ticks;
+    }
+
+    abstract public function generate(): string;
+    abstract public function getContentType(): string;
+
+    protected function buildTickUrl(int $tickId): string {
+        return Util::buildUrl($this->config->baseUrl, $this->config->basePath, "tick/{$tickId}");
+    }
+
+    protected function getSiteUrl(): string {
+        return Util::buildUrl($this->config->baseUrl, $this->config->basePath);
+    }
+}

src/Feed/RssGenerator.php

@@ -0,0 +1,47 @@
+<?php
+class RssGenerator extends FeedGenerator {
+    public function generate(): string {
+        $xml = '<?xml version="1.0" encoding="UTF-8"?>' . "\n";
+        $xml .= '<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">' . "\n";
+        $xml .= $this->buildChannel();
+        $xml .= '</rss>' . "\n";
+        return $xml;
+    }
+
+    public function getContentType(): string {
+        return 'application/rss+xml; charset=utf-8';
+    }
+
+    private function buildChannel(): string {
+        ob_start();
+        ?>
+<channel>
+    <title><?php echo Util::escape_xml($this->config->siteTitle . ' RSS Feed') ?></title>
+    <link><?php echo Util::escape_xml(Util::buildUrl($this->config->baseUrl, $this->config->basePath))?></link>
+    <atom:link href="<?php echo Util::escape_xml(Util::buildUrl($this->config->baseUrl, $this->config->basePath, 'feed/rss'))?>"
+               rel="self"
+               type="application/rss+xml" />
+    <description><?php echo Util::escape_xml($this->config->siteDescription) ?></description>
+    <language>en-us</language>
+    <lastBuildDate><?php echo date(DATE_RSS); ?></lastBuildDate>
+<?php foreach ($this->ticks as $tick):
+    // build the tick entry components
+    $tickPath = "tick/" . $tick['id'];
+    $tickUrl = Util::escape_xml($this->buildTickUrl($tick['id']));
+    $tickDate = date(DATE_RSS, strtotime($tick['timestamp']));
+    $tickTitle = Util::escape_xml($tick['tick']);
+    $tickDescription = Util::linkify($tickTitle);
+?>
+    <item>
+        <title><?php echo $tickTitle ?></title>
+        <link><?php echo $tickUrl; ?></link>
+        <description><?php echo $tickDescription; ?></description>
+        <pubDate><?php echo $tickDate; ?></pubDate>
+        <guid><?php echo $tickUrl; ?></guid>
+    </item>
+<?php endforeach; ?>
+</channel>
+<?php
+        return ob_get_clean();
+    }
+}

src/Framework/Router/Router.php

@@ -33,14 +33,14 @@ class Router {
             $controller = $routeHandler[1];
             $methods = $routeHandler[2] ?? ['GET'];
 
-            Log::debug("Route: '{$routePattern}', Controller {$controller}, Methods: ". implode(',' , $methods));
-
             # Only allow valid route and filename characters
             # to prevent directory traversal and other attacks
             $routePattern = preg_replace('/\{([^}]+)\}/', '([a-zA-Z0-9._-]+)', $routePattern);
             $routePattern = '#^' . $routePattern . '$#';
 
             if (preg_match($routePattern, $requestPath, $matches)) {
+                Log::debug("Request path: '{$requestPath}', Controller {$controller}, Methods: ". implode(',' , $methods));
+
                 if (in_array($requestMethod, $methods)){
                     // Save any path elements we're interested in
                     // (but discard the match on the entire path)

src/Framework/Util/Util.php

@@ -62,4 +62,21 @@ class Util {
         }
         return $diff->s . ' second' . ($diff->s != 1 ? 's' : '') . ' ago';
     }
+
+    public static function buildUrl(string $baseUrl, string $basePath, string $path = ''): string {
+        // Normalize baseUrl (remove trailing slash)
+        $baseUrl = rtrim($baseUrl, '/');
+        
+        // Normalize basePath (ensure leading slash, remove trailing slash unless it's just '/')
+        if ($basePath === '' || $basePath === '/') {
+            $basePath = '/';
+        } else {
+            $basePath = '/' . trim($basePath, '/') . '/';
+        }
+        
+        // Normalize path (remove leading slash if present)
+        $path = ltrim($path, '/');
+        
+        return $baseUrl . $basePath . $path;
+    }
 }

templates/feed/atom.php

@@ -1,40 +0,0 @@
-<?php /** @var ConfigModel $config */ ?>
-<?php /** @var array $ticks */ ?>
-<?php
-$feedTitle = Util::escape_xml("$config->siteTitle Atom Feed");
-$siteUrl = Util::escape_xml($config->baseUrl . $config->basePath);
-$feedUrl = Util::escape_xml($config->baseUrl . $config->basePath . 'feed/atom');
-$updated = date(DATE_ATOM, strtotime($ticks[0]['timestamp'] ?? 'now'));
-
-header('Content-Type: application/atom+xml; charset=utf-8');
-echo '<?xml version="1.0" encoding="utf-8"?>' . "\n";
-?>
-<feed xmlns="http://www.w3.org/2005/Atom">
-  <title><?php echo $feedTitle ?></title>
-  <link rel="self"
-        type="application/atom+xml"
-        title="<?php echo $feedTitle ?>"
-        href="<?php echo $feedUrl ?>" />
-  <link rel="alternate" href="<?php echo $siteUrl  ?>"/>
-  <updated><?php echo $updated ?></updated>
-  <id><?php echo $siteUrl ?></id>
-  <author>
-        <name><?= Util::escape_xml($config->siteTitle) ?></name>
-  </author>
-<?php foreach ($ticks as $tick):
-    // build the tick entry components
-    $tickPath = "tick/" . $tick['id'];
-    $tickUrl = Util::escape_xml($siteUrl . $basePath . $tickPath);
-    $tickTime = date(DATE_ATOM, strtotime($tick['timestamp']));
-    $tickTitle = Util::escape_xml($tick['tick']);
-    $tickContent = Util::linkify($tickTitle);
-?>
-  <entry>
-    <title><?= $tickTitle ?></title>
-    <link href="<?= $tickUrl ?>"/>
-    <id><?= $tickUrl ?></id>
-    <updated><?= $tickTime ?></updated>
-    <content type="html"><?= $tickContent ?></content>
-  </entry>
-<?php endforeach; ?>
-</feed>

templates/feed/rss.php

@@ -1,39 +0,0 @@
-<?php /** @var ConfigModel $config */ ?>
-<?php /** @var array $ticks */ ?>
-<?php
-// Need to have a little php here because the starting xml tag
-// will mess up the PHP parser.
-// TODO - I think short php tags can be disabled to prevent that.
-
-header('Content-Type: application/rss+xml; charset=utf-8');
-echo '<?xml version="1.0" encoding="UTF-8"?>' . "\n";
-?>
-<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
-<channel>
-    <title><?php echo Util::escape_xml($config->siteTitle . 'RSS Feed') ?></title>
-    <link><?php echo Util::escape_xml($config->baseUrl . $config->basePath)?></link>
-    <atom:link href="<?php echo Util::escape_xml($config->baseUrl . $config->basePath. 'feed/rss')?>"
-               rel="self"
-               type="application/rss+xml" />
-    <description><?php echo Util::escape_xml($config->siteDescription) ?></description>
-    <language>en-us</language>
-    <lastBuildDate><?php echo date(DATE_RSS); ?></lastBuildDate>
-<?php foreach ($ticks as $tick):
-    // build the tick entry components
-    //$tickPath = "tick/$year/$month/$day/$hour/$minute/$second";
-    $tickPath = "tick/" . $tick['id'];
-    $tickUrl = Util::escape_xml($config->baseUrl . $config->basePath . $tickPath);
-    $tickDate = date(DATE_RSS, strtotime($tick['timestamp']));
-    $tickTitle = Util::escape_xml($tick['tick']);
-    $tickDescription = Util::linkify($tickTitle);
-?>
-    <item>
-        <title><?php echo $tickTitle ?></title>
-        <link><?php echo $tickUrl; ?></link>
-        <description><?php echo $tickDescription; ?></description>
-        <pubDate><?php echo $tickDate; ?></pubDate>
-        <guid><?php echo $tickUrl; ?></guid>
-    </item>
-<?php endforeach; ?>
-</channel>
-</rss>

tests/Feed/AtomGeneratorTest.php

@@ -0,0 +1,139 @@
+<?php
+use PHPUnit\Framework\TestCase;
+
+class AtomGeneratorTest extends TestCase
+{
+    private function createMockConfig() {
+        $config = new ConfigModel();
+        $config->siteTitle = 'Test Site';
+        $config->siteDescription = 'Test Description';
+        $config->baseUrl = 'https://example.com';
+        $config->basePath = '/tkr/';
+        return $config;
+    }
+
+    private function createSampleTicks() {
+        return [
+            ['id' => 1, 'timestamp' => '2025-01-15 12:00:00', 'tick' => 'First test tick'],
+            ['id' => 2, 'timestamp' => '2025-01-15 13:00:00', 'tick' => 'Second test tick']
+        ];
+    }
+
+    public function testCanGenerateValidAtom() {
+        $config = $this->createMockConfig();
+        $ticks = $this->createSampleTicks();
+
+        $generator = new AtomGenerator($config, $ticks);
+        $xml = $generator->generate();
+
+        // Test XML structure
+        $this->assertStringStartsWith('<?xml version="1.0"', $xml);
+        $this->assertStringContainsString('<feed xmlns="http://www.w3.org/2005/Atom">', $xml);
+        $this->assertStringContainsString('<title>Test Site Atom Feed</title>', $xml);
+        $this->assertStringContainsString('<link rel="alternate" href="https://example.com/tkr/"/>', $xml);
+        $this->assertStringContainsString('<link rel="self"', $xml);
+        $this->assertStringContainsString('href="https://example.com/tkr/feed/atom"', $xml);
+        $this->assertStringContainsString('<id>https://example.com/tkr/</id>', $xml);
+        $this->assertStringContainsString('<author>', $xml);
+        $this->assertStringContainsString('<name>Test Site</name>', $xml);
+        $this->assertStringContainsString('<entry>', $xml);
+        $this->assertStringContainsString('</entry>', $xml);
+        $this->assertStringEndsWith('</feed>' . "\n", $xml);
+
+        // Test tick content
+        $this->assertStringContainsString('First test tick', $xml);
+        $this->assertStringContainsString('Second test tick', $xml);
+
+        // Ensure the XML is still valid
+        $doc = new DOMDocument();
+        $this->assertTrue($doc->loadXML($xml), 'Valid Atom should load into an XML document');
+    }
+
+    public function testReturnsCorrectContentType() {
+        $generator = new AtomGenerator($this->createMockConfig(), []);
+        $this->assertEquals('application/atom+xml; charset=utf-8', $generator->getContentType());
+    }
+
+    public function testCanHandleEmptyTickList() {
+        $config = $this->createMockConfig();
+        $generator = new AtomGenerator($config, []);
+        $xml = $generator->generate();
+
+        // Should still be valid Atom with no entries
+        // Test XML structure
+        $this->assertStringStartsWith('<?xml version="1.0"', $xml);
+        $this->assertStringContainsString('<feed xmlns="http://www.w3.org/2005/Atom">', $xml);
+        $this->assertStringContainsString('<title>Test Site Atom Feed</title>', $xml);
+        $this->assertStringContainsString('<link rel="alternate" href="https://example.com/tkr/"/>', $xml);
+        $this->assertStringContainsString('<link rel="self"', $xml);
+        $this->assertStringContainsString('href="https://example.com/tkr/feed/atom"', $xml);
+        $this->assertStringContainsString('<id>https://example.com/tkr/</id>', $xml);
+        $this->assertStringContainsString('<author>', $xml);
+        $this->assertStringContainsString('<name>Test Site</name>', $xml);
+        $this->assertStringEndsWith('</feed>' . "\n", $xml);
+
+        // Test tick content
+        $this->assertStringNotContainsString('<entry>', $xml);
+        $this->assertStringNotContainsString('</entry>', $xml);
+
+        // Ensure the XML is still valid
+        $doc = new DOMDocument();
+        $this->assertTrue($doc->loadXML($xml), 'XML with no entries should still be valid');
+    }
+
+    public function testCanHandleSpecialCharactersAndUnicode() {
+        $config = $this->createMockConfig();
+
+        // Test various challenging characters
+        $ticks = [
+            [
+                'id' => 1,
+                'timestamp' => '2025-01-15 12:00:00',
+                'tick' => 'Testing emojis 🎉🔥💯 and unicode characters'
+            ],
+            [
+                'id' => 2,
+                'timestamp' => '2025-01-15 13:00:00',
+                'tick' => 'XML entities: <tag> & "quotes" & \'apostrophes\''
+            ],
+            [
+                'id' => 3,
+                'timestamp' => '2025-01-15 14:00:00',
+                'tick' => 'International: café naïve résumé 北京 москва'
+            ],
+            [
+                'id' => 4,
+                'timestamp' => '2025-01-15 15:00:00',
+                'tick' => 'Math symbols: ∑ ∆ π ∞ ≠ ≤ ≥'
+            ]
+        ];
+
+        $generator = new AtomGenerator($config, $ticks);
+        $xml = $generator->generate();
+
+        // Test that emojis are preserved
+        $this->assertStringContainsString('🎉🔥💯', $xml);
+
+        // Test that XML entities are properly escaped
+        $this->assertStringContainsString('&lt;tag&gt;', $xml);
+        $this->assertStringContainsString('&amp;', $xml);
+        $this->assertStringContainsString('&quot;quotes&quot;', $xml);
+        $this->assertStringContainsString('&apos;apostrophes&apos;', $xml);
+
+        // Test that international characters are preserved
+        $this->assertStringContainsString('café naïve résumé', $xml);
+        $this->assertStringContainsString('北京', $xml);
+        $this->assertStringContainsString('москва', $xml);
+
+        // Test that math symbols are preserved
+        $this->assertStringContainsString('∑ ∆ π ∞', $xml);
+
+        // Ensure no raw < > & characters (security)
+        $this->assertStringNotContainsString('<tag>', $xml);
+        $this->assertStringNotContainsString(' & "', $xml);
+
+        // Ensure the XML is still valid
+        $doc = new DOMDocument();
+        $this->assertTrue($doc->loadXML($xml), 'XML with Unicode should still be valid');
+    }
+}

tests/Feed/FeedGeneratorTest.php

@@ -0,0 +1,114 @@
+<?php
+use PHPUnit\Framework\TestCase;
+
+class FeedGeneratorTest extends TestCase
+{
+    private function createMockConfig() {
+        $config = new ConfigModel();
+        $config->siteTitle = 'Test Site';
+        $config->siteDescription = 'Test Description';
+        $config->baseUrl = 'https://example.com';
+        $config->basePath = '/tkr/';
+        return $config;
+    }
+
+    private function createSampleTicks() {
+        return [
+            ['id' => 1, 'timestamp' => '2025-01-15 12:00:00', 'tick' => 'First test tick'],
+            ['id' => 2, 'timestamp' => '2025-01-15 13:00:00', 'tick' => 'Second test tick']
+        ];
+    }
+
+    private function createTestGenerator($config = null, $ticks = null) {
+        $config = $config ?? $this->createMockConfig();
+        $ticks = $ticks ?? $this->createSampleTicks();
+
+        return new class($config, $ticks) extends FeedGenerator {
+            public function generate(): string {
+                return '<test>content</test>';
+            }
+
+            public function getContentType(): string {
+                return 'application/test+xml';
+            }
+
+            // Expose protected methods for testing
+            public function testBuildTickUrl(int $tickId): string {
+                return $this->buildTickUrl($tickId);
+            }
+
+            public function testGetSiteUrl(): string {
+                return $this->getSiteUrl();
+            }
+        };
+    }
+
+    public function testConstructorStoresConfigAndTicks() {
+        $generator = $this->createTestGenerator();
+
+        $this->assertEquals('<test>content</test>', $generator->generate());
+        $this->assertEquals('application/test+xml', $generator->getContentType());
+    }
+
+    public function testBuildTickUrlGeneratesCorrectUrl() {
+        $generator = $this->createTestGenerator();
+
+        $tickUrl = $generator->testBuildTickUrl(123);
+        $this->assertEquals('https://example.com/tkr/tick/123', $tickUrl);
+    }
+
+    public function testGetSiteUrlGeneratesCorrectUrl() {
+        $generator = $this->createTestGenerator();
+
+        $siteUrl = $generator->testGetSiteUrl();
+        $this->assertEquals('https://example.com/tkr/', $siteUrl);
+    }
+
+    public function testUrlMethodsHandleSubdomainConfiguration() {
+        $config = new ConfigModel();
+        $config->siteTitle = 'Test Site';
+        $config->baseUrl = 'https://tkr.example.com';
+        $config->basePath = '/';
+
+        $generator = $this->createTestGenerator($config, []);
+
+        $this->assertEquals('https://tkr.example.com/', $generator->testGetSiteUrl());
+        $this->assertEquals('https://tkr.example.com/tick/456', $generator->testBuildTickUrl(456));
+    }
+
+    public function testUrlMethodsHandleEmptyBasePath() {
+        $config = new ConfigModel();
+        $config->siteTitle = 'Test Site';
+        $config->baseUrl = 'https://example.com';
+        $config->basePath = '';
+
+        $generator = $this->createTestGenerator($config, []);
+
+        $this->assertEquals('https://example.com/', $generator->testGetSiteUrl());
+        $this->assertEquals('https://example.com/tick/789', $generator->testBuildTickUrl(789));
+    }
+
+    public function testUrlMethodsHandleVariousBasePathFormats() {
+        $testCases = [
+            // [basePath, expectedSiteUrl, expectedTickUrl]
+            ['', 'https://example.com/', 'https://example.com/tick/123'],
+            ['/', 'https://example.com/', 'https://example.com/tick/123'],
+            ['tkr', 'https://example.com/tkr/', 'https://example.com/tkr/tick/123'],
+            ['/tkr', 'https://example.com/tkr/', 'https://example.com/tkr/tick/123'],
+            ['tkr/', 'https://example.com/tkr/', 'https://example.com/tkr/tick/123'],
+            ['/tkr/', 'https://example.com/tkr/', 'https://example.com/tkr/tick/123'],
+        ];
+
+        foreach ($testCases as [$basePath, $expectedSiteUrl, $expectedTickUrl]) {
+            $config = new ConfigModel();
+            $config->siteTitle = 'Test Site';
+            $config->baseUrl = 'https://example.com';
+            $config->basePath = $basePath;
+
+            $generator = $this->createTestGenerator($config, []);
+
+            $this->assertEquals($expectedSiteUrl, $generator->testGetSiteUrl(), "Failed for basePath: '$basePath'");
+            $this->assertEquals($expectedTickUrl, $generator->testBuildTickUrl(123), "Failed for basePath: '$basePath'");
+        }
+    }
+}

tests/Feed/RssGeneratorTest.php

@@ -0,0 +1,135 @@
+<?php
+use PHPUnit\Framework\TestCase;
+
+class RssGeneratorTest extends TestCase
+{
+    private function createMockConfig() {
+        $config = new ConfigModel();
+        $config->siteTitle = 'Test Site';
+        $config->siteDescription = 'Test Description';
+        $config->baseUrl = 'https://example.com';
+        $config->basePath = '/tkr/';
+        return $config;
+    }
+
+    private function createSampleTicks() {
+        return [
+            ['id' => 1, 'timestamp' => '2025-01-15 12:00:00', 'tick' => 'First test tick'],
+            ['id' => 2, 'timestamp' => '2025-01-15 13:00:00', 'tick' => 'Second test tick']
+        ];
+    }
+
+    public function testCanGenerateValidRss() {
+        $config = $this->createMockConfig();
+        $ticks = $this->createSampleTicks();
+
+        $generator = new RssGenerator($config, $ticks);
+        $xml = $generator->generate();
+
+        // Test XML structure
+        $this->assertStringStartsWith('<?xml version="1.0"', $xml);
+        $this->assertStringContainsString('<rss version="2.0"', $xml);
+        $this->assertStringContainsString('<title>Test Site RSS Feed</title>', $xml);
+        $this->assertStringContainsString('<link>https://example.com/tkr/</link>', $xml);
+        $this->assertStringContainsString('<atom:link href="https://example.com/tkr/feed/rss"', $xml);
+        $this->assertStringContainsString('<channel>', $xml);
+        $this->assertStringContainsString('<item>', $xml);
+        $this->assertStringContainsString('</item>', $xml);
+        $this->assertStringContainsString('</channel>', $xml);
+        $this->assertStringEndsWith('</rss>' . "\n", $xml);
+
+        // Test tick content
+        $this->assertStringContainsString('First test tick', $xml);
+        $this->assertStringContainsString('Second test tick', $xml);
+
+        // Ensure the XML is still valid
+        $doc = new DOMDocument();
+        $this->assertTrue($doc->loadXML($xml), 'Valid RSS should load into an XML document');
+    }
+
+    public function testReturnsCorrectContentType() {
+        $generator = new RssGenerator($this->createMockConfig(), []);
+        $this->assertEquals('application/rss+xml; charset=utf-8', $generator->getContentType());
+    }
+
+    public function testCanHandleEmptyTickList() {
+        $config = $this->createMockConfig();
+        $generator = new RssGenerator($config, []);
+        $xml = $generator->generate();
+
+        // Should still be valid RSS with no items
+        // Test XML structure
+        $this->assertStringStartsWith('<?xml version="1.0"', $xml);
+        $this->assertStringContainsString('<rss version="2.0"', $xml);
+        $this->assertStringContainsString('<title>Test Site RSS Feed</title>', $xml);
+        $this->assertStringContainsString('<link>https://example.com/tkr/</link>', $xml);
+        $this->assertStringContainsString('<atom:link href="https://example.com/tkr/feed/rss"', $xml);
+        $this->assertStringContainsString('<channel>', $xml);
+        $this->assertStringContainsString('</channel>', $xml);
+        $this->assertStringEndsWith('</rss>' . "\n", $xml);
+
+        // Test tick content
+        $this->assertStringNotContainsString('<item>', $xml);
+        $this->assertStringNotContainsString('</item>', $xml);
+
+        // Ensure the XML is still valid
+        $doc = new DOMDocument();
+        $this->assertTrue($doc->loadXML($xml), 'XML with no items should still be valid');
+    }
+
+    public function testCanHandleSpecialCharactersAndUnicode() {
+        $config = $this->createMockConfig();
+
+        // Test various challenging characters
+        $ticks = [
+            [
+                'id' => 1,
+                'timestamp' => '2025-01-15 12:00:00',
+                'tick' => 'Testing emojis 🎉🔥💯 and unicode characters'
+            ],
+            [
+                'id' => 2,
+                'timestamp' => '2025-01-15 13:00:00',
+                'tick' => 'XML entities: <tag> & "quotes" & \'apostrophes\''
+            ],
+            [
+                'id' => 3,
+                'timestamp' => '2025-01-15 14:00:00',
+                'tick' => 'International: café naïve résumé 北京 москва'
+            ],
+            [
+                'id' => 4,
+                'timestamp' => '2025-01-15 15:00:00',
+                'tick' => 'Math symbols: ∑ ∆ π ∞ ≠ ≤ ≥'
+            ]
+        ];
+
+        $generator = new RssGenerator($config, $ticks);
+        $xml = $generator->generate();
+
+        // Test that emojis are preserved
+        $this->assertStringContainsString('🎉🔥💯', $xml);
+
+        // Test that XML entities are properly escaped
+        $this->assertStringContainsString('&lt;tag&gt;', $xml);
+        $this->assertStringContainsString('&amp;', $xml);
+        $this->assertStringContainsString('&quot;quotes&quot;', $xml);
+        $this->assertStringContainsString('&apos;apostrophes&apos;', $xml);
+
+        // Test that international characters are preserved
+        $this->assertStringContainsString('café naïve résumé', $xml);
+        $this->assertStringContainsString('北京', $xml);
+        $this->assertStringContainsString('москва', $xml);
+
+        // Test that math symbols are preserved
+        $this->assertStringContainsString('∑ ∆ π ∞', $xml);
+
+        // Ensure no raw < > & characters (security)
+        $this->assertStringNotContainsString('<tag>', $xml);
+        $this->assertStringNotContainsString(' & "', $xml);
+
+        // Ensure the XML is still valid
+        $doc = new DOMDocument();
+        $this->assertTrue($doc->loadXML($xml), 'XML with Unicode should still be valid');
+    }
+}