fix(Helpers): prevent TypeError in excerpt() when phrase is not found or radius is odd

docs/helpers/text_helper.md

@@ -489,7 +489,7 @@ this_string_is_e…ak_my_design.jpg
 
 This function will extract `$radius` number of characters before and after the central `$phrase` with an ellipsis before and after.
 
-The first parameter is the text to extract an excerpt from, and the second is the central word or phrase to count before and after. The third parameter is the number of characters to count before and after the central phrase. If no phrase is passed, the excerpt will include the first `$radius` characters with the ellipsis at the end.
+The first parameter is the text to extract an excerpt from, and the second is the central word or phrase to count before and after. The third parameter is the number of characters to count before and after the central phrase. If no phrase is passed, or if the phrase is not found in the text, the excerpt will include the first `$radius` characters with the ellipsis at the end.
 
 Example:
 

system/Helpers/text_helper.php

@@ -709,16 +709,20 @@ function alternator(...$args): string
      * @param int    $radius   The amount of characters returned around the phrase.
      * @param string $ellipsis Ending that will be appended
      *
-     * If no $phrase is passed, will generate an excerpt of $radius characters
-     * from the beginning of $text.
+     * If no $phrase is passed or $phrase is not found, will generate an excerpt
+     * of $radius characters from the beginning of $text.
      */
     function excerpt(string $text, ?string $phrase = null, int $radius = 100, string $ellipsis = '...'): string
     {
         if (isset($phrase)) {
             $phrasePosition = mb_stripos($text, $phrase);
             $phraseLength   = mb_strlen($phrase);
+
+            if ($phrasePosition === false) {
+                return excerpt($text, null, $radius, $ellipsis);
+            }
         } else {
-            $phrasePosition = $radius / 2;
+            $phrasePosition = intdiv($radius, 2);
             $phraseLength   = 1;
         }
 

tests/system/Helpers/TextHelperTest.php

@@ -450,6 +450,24 @@ public function testExcerptRadius(): void
         $this->assertSame($multibyteResult, excerpt($this->mbLongString, 'печально', 10));
     }
 
+    public function testExcerptPhraseNotFound(): void
+    {
+        $result = ' Once upon a time, a framework had no tests. It sad  So some nice people began to write tests. The more time that went on, the happier it became. ...';
+        $this->assertSame($result, excerpt($this->longString, 'nonexistent'));
+
+        $multibyteResult = ' Давным-давно во фреймворке не было тестов. Это печ льно. И вот несколько хороших людей начали писать тесты. Чем больше времени проходило, тем ...';
+        $this->assertSame($multibyteResult, excerpt($this->mbLongString, 'несуществующее'));
+    }
+
+    public function testExcerptOddRadius(): void
+    {
+        $result = ' Once upon a time, a framework had no tests. It sad  So some nice people began to write tests. The more time that went on, the happier it became. ...';
+        $this->assertSame($result, excerpt($this->longString, null, 101));
+
+        $multibyteResult = ' Давным-давно во фреймворке не было тестов. Это печ льно. И вот несколько хороших людей начали писать тесты. Чем больше времени проходило, тем ...';
+        $this->assertSame($multibyteResult, excerpt($this->mbLongString, null, 101));
+    }
+
     public function testAlternator(): void
     {
         $phrase = ' scream! ';