feat(randomizer): randomizer may throw a range exception

src/Randomizer.php

@@ -21,8 +21,15 @@ public function __construct(
     ) {
     }
 
+    /**
+     * {@inheritDoc}
+     */
     public function random(): int
     {
+        if ($this->min > $this->max) {
+            throw new \RangeException('max value is not greater than or equal to min value');
+        }
+
         return \mt_rand($this->min, $this->max);
     }
 }

src/RandomizerInterface.php

@@ -15,5 +15,8 @@
 
 interface RandomizerInterface
 {
+    /**
+     * @throws \RangeException if a range error at connstruction or at draw.
+     */
     public function random(): int;
 }

tests/RandomizerTest.php

@@ -30,4 +30,17 @@ public function testRandom()
         $this->assertGreaterThanOrEqual(1, $actual);
         $this->assertLessThanOrEqual(6, $actual);
     }
+
+    public function testRangeException()
+    {
+        // Given
+        $this->expectException(\RangeException::class);
+        $this->expectExceptionMessage('max value is not greater than or equal to min value');
+
+        // When
+        (new Randomizer(2, 1))->random();
+
+        // Then
+        // An exception is thrown
+    }
 }