CreateIndexes can require that $indexes be a list

src/Operation/CreateIndexes.php

@@ -40,7 +40,13 @@ class CreateIndexes implements Executable
             throw new InvalidArgumentException('$indexes is empty');
         }
 
-        foreach ($indexes as $index) {
+        $expectedIndex = 0;
+
+        foreach ($indexes as $i => $index) {
+            if ($i !== $expectedIndex) {
+                throw new InvalidArgumentException(sprintf('$indexes is not a list (unexpected index: "%s")', $i));
+            }
+
             if ( ! is_array($index)) {
                 throw new InvalidArgumentTypeException(sprintf('$index[%d]', $i), $index, 'array');
             }
@@ -50,6 +56,8 @@ class CreateIndexes implements Executable
             }
 
             $this->indexes[] = new IndexInput($index);
+
+            $expectedIndex += 1;
         }
 
         $this->databaseName = (string) $databaseName;

tests/Operation/CreateIndexesTest.php

@@ -16,7 +16,16 @@ class CreateIndexesTest extends TestCase
     }
 
     /**
-     * @expectedException MongoDB\Exception\UnexpectedTypeException
+     * @expectedException MongoDB\Exception\InvalidArgumentException
+     * @expectedExceptionMessage $indexes is not a list (unexpected index: "1")
+     */
+    public function testConstructorIndexesArgumentMustBeAList()
+    {
+        new CreateIndexes($this->getDatabaseName(), $this->getCollectionName(), [1 => ['key' => ['x' => 1]]]);
+    }
+
+    /**
+     * @expectedException MongoDB\Exception\InvalidArgumentTypeException
      * @dataProvider provideInvalidIndexSpecificationTypes
      */
     public function testCreateIndexesRequiresIndexSpecificationsToBeAnArray($index)