Add test on UnifiedTestRunner EntityMapObserver

Author: GromNaN

tests/UnifiedSpecTests/UnifiedTestRunner.php

@@ -125,6 +125,8 @@ public function run(UnifiedTestCase $test): void
      *
      * This function is primarily used by the Atlas testing workload executor.
      *
+     * @see https://github.com/mongodb-labs/drivers-atlas-testing/
+     *
      * @param callable(EntityMap):void $entityMapObserver
      */
     public function setEntityMapObserver(callable $entityMapObserver): void

tests/UnifiedSpecTests/UnifiedTestRunnerTest.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace MongoDB\Tests\UnifiedSpecTests;
+
+use MongoDB\Tests\FunctionalTestCase;
+
+class UnifiedTestRunnerTest extends FunctionalTestCase
+{
+    public function testEntityMapObserver(): void
+    {
+        $test = UnifiedTestCase::fromFile(__DIR__ . '/crud/find.json');
+        $calls = 0;
+
+        $runner = new UnifiedTestRunner(static::getUri());
+        $runner->setEntityMapObserver(function (EntityMap $entityMap) use (&$calls): void {
+            $this->assertArrayHasKey('client0', $entityMap);
+            $this->assertArrayHasKey('database0', $entityMap);
+            $this->assertArrayHasKey('collection0', $entityMap);
+            $calls++;
+        });
+
+        $runner->run($test->current());
+        $this->assertSame(1, $calls);
+    }
+}