Add tests for footnotes functionality in ParsedownExtended

Author: BenjaminHoegh

tests/FootnotesTest.php

@@ -17,4 +17,39 @@ protected function tearDown(): void
     {
         unset($this->parsedownExtended);
     }
+
+    public function testFootnotesEnabled()
+    {
+        $this->parsedownExtended->config()->set('footnotes', true);
+
+        $markdown = "Text with a footnote.[^1]\n\n[^1]: The footnote content.";
+        $html = $this->parsedownExtended->text($markdown);
+
+        $this->assertStringContainsString('<sup', $html);
+        $this->assertStringContainsString('The footnote content.', $html);
+    }
+
+    public function testFootnotesDisabled()
+    {
+        $this->parsedownExtended->config()->set('footnotes', false);
+
+        $markdown = "Text with a footnote.[^1]\n\n[^1]: The footnote content.";
+        $html = $this->parsedownExtended->text($markdown);
+
+        // When footnotes are disabled there should be no superscript footnote links
+        $this->assertStringNotContainsString('<sup', $html);
+        // The footnote definition is not processed as a footnote, so no back-reference link appears
+        $this->assertStringNotContainsString('href="#fn:', $html);
+    }
+
+    public function testMultipleFootnotes()
+    {
+        $this->parsedownExtended->config()->set('footnotes', true);
+
+        $markdown = "First[^1] and second[^2].\n\n[^1]: First footnote.\n\n[^2]: Second footnote.";
+        $html = $this->parsedownExtended->text($markdown);
+
+        $this->assertStringContainsString('First footnote.', $html);
+        $this->assertStringContainsString('Second footnote.', $html);
+    }
 }