fix: spec update (PR #7) - blocklist filtering in uppercase-only alph…

…abet

CHANGELOG.md

@@ -1,5 +1,8 @@
 # CHANGELOG
 
+**v0.3.1:**
+- Bug fix: spec update (PR #7): blocklist filtering in uppercase-only alphabet [[PR #7](https://github.com/sqids/sqids-spec/pull/7)]
+
 **v0.3.0:**
 - Bug fix: test for decoding an invalid ID with a repeating reserved character
 - Removing requirement of `ext-mbstring`

src/Sqids.php

@@ -617,13 +617,14 @@ public function __construct(
         }
 
         $filteredBlocklist = [];
-        $alphabetChars = str_split($alphabet);
+        $alphabetChars = str_split(strtolower($alphabet));
         foreach ((array) $blocklist as $word) {
             if (strlen((string) $word) >= 3) {
-                $wordChars = str_split((string) $word);
+                $wordLowercased = strtolower($word);
+                $wordChars = str_split((string) $wordLowercased);
                 $intersection = array_filter($wordChars, fn ($c) => in_array($c, $alphabetChars));
                 if (count($intersection) == count($wordChars)) {
-                    $filteredBlocklist[] = strtolower((string) $word);
+                    $filteredBlocklist[] = strtolower((string) $wordLowercased);
                 }
             }
         }

tests/SqidsBlocklistTest.php

@@ -79,4 +79,16 @@ public function testMatchAgainstAShortBlocklistWord()
         $sqids = new Sqids('', 0, ['pPQ']);
         $this->assertSame([1000], $sqids->decode($sqids->encode([1000])));
     }
+
+    public function testBlocklistFilteringInConstructor()
+    {
+        // lowercase blocklist in only-uppercase alphabet
+        $sqids = new Sqids('ABCDEFGHIJKLMNOPQRSTUVWXYZ', 0, ['sqnmpn']);
+
+        $id = $sqids->encode([1, 2, 3]);
+        $numbers = $sqids->decode($id);
+
+        $this->assertSame($id, 'ULPBZGBM'); // without blocklist, would've been "SQNMPN"
+        $this->assertSame($numbers, [1, 2, 3]);
+    }
 }