fix: add more php versions and update test cases

.github/workflows/test-analyze-tag-release.yml

@@ -13,7 +13,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php-version: [ '8.0', '8.1', '8.2', '8.3', '8.4', '8.5' ]
+        php-version: [ '7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3', '8.4', '8.5' ]
 
     steps:
       - name: Checkout code
@@ -26,6 +26,9 @@ jobs:
           coverage: pcov
           tools: composer:v2
 
+      - name: Remove packages from composer.json
+        run: composer remove php-cs-fixer/shim phpstan/phpstan --dev
+
       - name: Validate composer.json
         run: composer validate --strict
 

.php-cs-fixer.dist.php

@@ -8,8 +8,14 @@
 return (new Config())
     ->setRiskyAllowed(false)
     ->setRules([
+        '@PHP7x0Migration' => true,
         '@Symfony' => true,
         '@PhpCsFixer' => true,
+        'nullable_type_declaration_for_default_null_value' => false,
+        'phpdoc_no_empty_return' => false,
+        'modifier_keywords' => [
+            'elements' => ['property', 'method'],
+        ],
     ])
     // 💡 by default, Fixer looks for `*.php` files excluding `./vendor/` - here, you can groom this config
     ->setFinder(

README.md

@@ -34,7 +34,7 @@ It is **not** appropriate when an exact distinct count is required.
 
 ## Requirements
 
-- **PHP 8.0, 8.1, 8.2, 8.3, 8.4 and 8.5**
+- **PHP 7.0, 7.1, 7.2, 7.3, 7.4, 8.0, 8.1, 8.2, 8.3, 8.4 and 8.5**
 - No external dependencies
 
 > **Note:** The `xxh3` and `xxh128` hash algorithms are available only when supported by your PHP version and build. If

composer.json

@@ -17,12 +17,12 @@
     }
   ],
   "require": {
-    "php": "^8.0"
+    "php": "^8.0|^7.0"
   },
   "require-dev": {
     "php-cs-fixer/shim": "^3.95",
     "phpstan/phpstan": "^2.2",
-    "phpunit/phpunit": "^9.6"
+    "phpunit/phpunit": "^9.6|^8.5|^6.5"
   },
   "autoload": {
     "psr-4": {
@@ -50,4 +50,4 @@
     "sort-packages": true,
     "optimize-autoloader": true
   }
-}
+}

src/HyperLogLog.php

@@ -16,18 +16,22 @@
 class HyperLogLog
 {
     /** @var int */
-    private const TWO_POW_32 = 4_294_967_296;
-    private int $counterBits;
+    const TWO_POW_32 = 4294967296;
 
-    private string $hashAlgorithm;
+    /** @var int */
+    private $counterBits;
+
+    /** @var string */
+    private $hashAlgorithm;
 
-    private int $m;
+    /** @var int */
+    private $m;
 
     /** @var array<int, int> Counters storing maximum rho values */
-    private array $counters;
+    private $counters;
 
     /** @var bool Indicates if the selected hash algorithm produces less than 64 bits */
-    private bool $needsPadding;
+    private $needsPadding;
 
     /**
      * HyperLogLog constructor.
@@ -95,8 +99,10 @@ public function setCounters(array $counters): self
      * and leading zero count, and the register is updated with the maximum observed rho value.
      *
      * @param string $value element to insert
+     *
+     * @return void
      */
-    public function add(string $value): void
+    public function add(string $value)
     {
         $hashString = $this->hash($value, $this->hashAlgorithm);
 
@@ -179,7 +185,9 @@ public function merge(self $other): self
         }
 
         $this->counters = array_map(
-            static fn (int $counter, int $otherCounter): int => max($counter, $otherCounter),
+            static function (int $counter, int $otherCounter): int {
+                return max($counter, $otherCounter);
+            },
             $this->counters,
             $other->counters
         );
@@ -221,17 +229,34 @@ public function alpha(int $m): float
             throw new \InvalidArgumentException('Invalid number of counters, $m must be greater than 0');
         }
 
-        return match ($m) {
-            2 => 0.46852874309841,
-            4 => 0.56806457964166,
-            8 => 0.63557660535301,
-            16 => 0.673,
-            32 => 0.697,
-            64 => 0.709,
-            128 => 0.71527049326382,
-            256 => 0.71827259324955,
-            default => 0.7213 / (1 + 1.079 / $m),
-        };
+        switch ($m) {
+            case 2:
+                return 0.46852874309841;
+
+            case 4:
+                return 0.56806457964166;
+
+            case 8:
+                return 0.63557660535301;
+
+            case 16:
+                return 0.673;
+
+            case 32:
+                return 0.697;
+
+            case 64:
+                return 0.709;
+
+            case 128:
+                return 0.71527049326382;
+
+            case 256:
+                return 0.71827259324955;
+
+            default:
+                return 0.7213 / (1 + 1.079 / $m);
+        }
     }
 
     /**