fix: improve validation in Priority::withFairnessWeight and add unit tests (#719)

Author: xepozz

src/Common/Priority.php

@@ -136,9 +136,11 @@ public function withFairnessKey(string $value): self
      */
     public function withFairnessWeight(float $value): self
     {
-        $value < 0.001 or $value > 1000.0 and throw new \InvalidArgumentException(
-            'FairnessWeight must be in the range [0.001, 1000].',
-        );
+        if ($value < 0.001 || $value > 1000.0) {
+            throw new \InvalidArgumentException(
+                'FairnessWeight must be in the range [0.001, 1000].',
+            );
+        }
         $clone = clone $this;
         $clone->fairnessWeight = $value;
         return $clone;

tests/Unit/Common/PriorityTestCase.php

@@ -0,0 +1,63 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Temporal\Tests\Unit\Common;
+
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\TestCase;
+use Temporal\Common\Priority;
+
+final class PriorityTestCase extends TestCase
+{
+    public function testWithFairnessWeightValidValue(): void
+    {
+        $priority = Priority::new()->withFairnessWeight(1.0);
+
+        $this->assertSame(1.0, $priority->fairnessWeight);
+    }
+
+    public function testWithFairnessWeightMinBoundary(): void
+    {
+        $priority = Priority::new()->withFairnessWeight(0.001);
+
+        $this->assertSame(0.001, $priority->fairnessWeight);
+    }
+
+    public function testWithFairnessWeightMaxBoundary(): void
+    {
+        $priority = Priority::new()->withFairnessWeight(1000.0);
+
+        $this->assertSame(1000.0, $priority->fairnessWeight);
+    }
+
+    #[DataProvider('invalidFairnessWeightProvider')]
+    public function testWithFairnessWeightThrowsOnInvalidValue(float $value): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('FairnessWeight must be in the range [0.001, 1000].');
+
+        Priority::new()->withFairnessWeight($value);
+    }
+
+    public static function invalidFairnessWeightProvider(): iterable
+    {
+        return [
+            'zero' => [0.0],
+            'below minimum' => [0.0009],
+            'negative' => [-1.0],
+            'above maximum' => [1000.1],
+            'large value' => [9999.0],
+        ];
+    }
+
+    public function testWithFairnessWeightIsImmutable(): void
+    {
+        $original = Priority::new();
+        $modified = $original->withFairnessWeight(5.0);
+
+        $this->assertNotSame($original, $modified);
+        $this->assertSame(0.0, $original->fairnessWeight);
+        $this->assertSame(5.0, $modified->fairnessWeight);
+    }
+}