Improved MemoryInterrupter testability

src/MemoryInterrupter.php

@@ -13,27 +13,38 @@ final class MemoryInterrupter
      */
     private $maxBytes;
 
-    public function __construct(int $maxBytes)
+    /**
+     * @psalm-var callable(): int
+     */
+    private $memoryGetUsage;
+
+    /**
+     * @psalm-param ?callable(): int $memoryGetUsage
+     */
+    public function __construct(int $maxBytes, ?callable $memoryGetUsage = null)
     {
         if ($maxBytes <= 0) {
             throw new \InvalidArgumentException(sprintf('Parameter $maxBytes must be a positive integer, got %d.', $maxBytes));
         }
 
         $this->maxBytes = $maxBytes;
+        $this->memoryGetUsage = $memoryGetUsage ?? static function (): int { return memory_get_usage(true); };
     }
 
     public function __invoke(Context $context): void
     {
-        $usedMemory = memory_get_usage(true);
+        $usedMemory = ($this->memoryGetUsage)();
 
         if ($usedMemory < $this->maxBytes) {
             return;
         }
 
         $context->stop();
-        $context->log('Worker stopped after exceeding the memory limit of {limit} bytes ({memory} bytes used).', [
-            'limit' => $this->maxBytes,
-            'memory' => $usedMemory,
-        ], LogLevel::WARNING);
+
+        $context->log(
+            'Worker stopped after exceeding the memory limit of {limit} bytes ({memory} bytes used).',
+            ['limit' => $this->maxBytes, 'memory' => $usedMemory],
+            LogLevel::WARNING
+        );
     }
 }