Add support for <s> tag when converting HTML to RichText

Fixes #4223

Author: m7913d

src/PhpSpreadsheet/Helper/Html.php

@@ -561,6 +561,7 @@ class Html
         'u' => [self::class, 'startUnderlineTag'],
         'ins' => [self::class, 'startUnderlineTag'],
         'del' => [self::class, 'startStrikethruTag'],
+        's' => [self::class, 'startStrikethruTag'],
         'sup' => [self::class, 'startSuperscriptTag'],
         'sub' => [self::class, 'startSubscriptTag'],
     ];
@@ -575,6 +576,7 @@ class Html
         'u' => [self::class, 'endUnderlineTag'],
         'ins' => [self::class, 'endUnderlineTag'],
         'del' => [self::class, 'endStrikethruTag'],
+        's' => [self::class, 'endStrikethruTag'],
         'sup' => [self::class, 'endSuperscriptTag'],
         'sub' => [self::class, 'endSubscriptTag'],
         'br' => [self::class, 'breakTag'],

tests/PhpSpreadsheetTests/Helper/HtmlTest.php

@@ -48,4 +48,23 @@ public function testLiTag(): void
 
         self::assertSame($expected, $actual->getPlainText());
     }
+
+    public function testSTag(): void
+    {
+        $html = new Html();
+        $input = 'Hello <s>test</s>world';
+        $richText = $html->toRichTextObject($input);
+        $elements = $richText->getRichTextElements();
+
+        self::assertSame(count($elements), 3);
+
+        self::assertSame($elements[0]->getText(), 'Hello ');
+        self::assertTrue($elements[0]->getFont() === null || !$elements[0]->getFont()->getStrikethrough());
+
+        self::assertSame($elements[1]->getText(), 'test');
+        self::assertTrue($elements[1]->getFont() !== null && $elements[1]->getFont()->getStrikethrough());
+
+        self::assertSame($elements[2]->getText(), 'world');
+        self::assertTrue($elements[2]->getFont() === null || !$elements[2]->getFont()->getStrikethrough());
+    }
 }