PHPLIB-457: Add missing change stream prose test 14

Author: alcaeus

tests/Operation/WatchFunctionalTest.php

@@ -11,6 +11,7 @@
 use MongoDB\Driver\Exception\LogicException;
 use MongoDB\Driver\Exception\ServerException;
 use MongoDB\Driver\Manager;
+use MongoDB\Driver\Monitoring\CommandSucceededEvent;
 use MongoDB\Driver\ReadPreference;
 use MongoDB\Driver\WriteConcern;
 use MongoDB\Exception\ResumeTokenException;
@@ -1403,6 +1404,67 @@ public function testGetResumeTokenReturnsOriginalResumeTokenOnEmptyBatch()
         $this->assertSame($resumeToken, $changeStream->getResumeToken());
     }
 
+    /**
+     * For a ChangeStream under these conditions:
+     *  - The batch is not empty.
+     *  - The batch hasn’t been iterated at all.
+     *  - Only the initial aggregate command has been executed.
+     * Expected result:
+     *  - getResumeToken must return startAfter from the initial aggregate if the option was specified.
+     *  - getResumeToken must return resumeAfter from the initial aggregate if the option was specified.
+     *  - If neither the startAfter nor resumeAfter options were specified, the getResumeToken result must be empty.
+     */
+    public function testResumeTokenBehaviour()
+    {
+        if (version_compare($this->getServerVersion(), '4.1.1', '<')) {
+            $this->markTestSkipped('Testing resumeAfter and startAfter can only be tested on servers >= 4.1.1');
+        }
+
+        $operation = new Watch($this->manager, $this->getDatabaseName(), $this->getCollectionName(), [], $this->defaultOptions);
+
+        $lastOpTime = null;
+
+        $changeStream = null;
+        (new CommandObserver())->observe(function () use ($operation, &$changeStream) {
+            $changeStream = $operation->execute($this->getPrimaryServer());
+        }, function ($event) use (&$lastOpTime) {
+            $this->assertInstanceOf(CommandSucceededEvent::class, $event['succeeded']);
+            $reply = $event['succeeded']->getReply();
+
+            $this->assertObjectHasAttribute('operationTime', $reply);
+            $lastOpTime = $reply->operationTime;
+        });
+
+        $this->insertDocument(['x' => 1]);
+
+        $changeStream->next();
+        $this->assertTrue($changeStream->valid());
+        $resumeToken = $changeStream->getResumeToken();
+
+        $this->insertDocument(['x' => 2]);
+
+        // Test startAfter option
+        $options = ['startAfter' => $resumeToken] + $this->defaultOptions;
+        $operation = new Watch($this->manager, $this->getDatabaseName(), $this->getCollectionName(), [], $options);
+        $changeStream = $operation->execute($this->getPrimaryServer());
+
+        $this->assertEquals($resumeToken, $changeStream->getResumeToken());
+
+        // Test resumeAfter option
+        $options = ['resumeAfter' => $resumeToken] + $this->defaultOptions;
+        $operation = new Watch($this->manager, $this->getDatabaseName(), $this->getCollectionName(), [], $options);
+        $changeStream = $operation->execute($this->getPrimaryServer());
+
+        $this->assertEquals($resumeToken, $changeStream->getResumeToken());
+
+        // Test without option
+        $options = ['startAtOperationTime' => $lastOpTime] + $this->defaultOptions;
+        $operation = new Watch($this->manager, $this->getDatabaseName(), $this->getCollectionName(), [], $options);
+        $changeStream = $operation->execute($this->getPrimaryServer());
+
+        $this->assertNull($changeStream->getResumeToken());
+    }
+
     /**
      * Prose test: "$changeStream stage for ChangeStream started with startAfter
      * against a server >=4.1.1 that has not received any results yet MUST