From 8b03499b5344a9a076b5ced6d497b542e1b5b2d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Tamarelle?= <jerome@tamarelle.net>
Date: Fri, 29 Sep 2023 10:59:46 +0200
Subject: [PATCH] Static analysis

---
 psalm-baseline.xml                 |  6 +++++-
 src/Builder/BuilderEncoder.php     |  2 +-
 src/Builder/Pipeline.php           | 30 ++++++++++++++++++++++++------
 tests/Builder/BuilderCodecTest.php | 23 ++++++++++++++---------
 4 files changed, 44 insertions(+), 17 deletions(-)

diff --git a/psalm-baseline.xml b/psalm-baseline.xml
index 2657e5c58..a06fddc08 100644
--- a/psalm-baseline.xml
+++ b/psalm-baseline.xml
@@ -65,7 +65,6 @@
       <code>$query</code>
       <code>$result</code>
       <code>$result[]</code>
-      <code>$stage</code>
       <code>$val</code>
       <code>$val</code>
     </MixedAssignment>
@@ -83,6 +82,11 @@
       <code><![CDATA[$mergedDriver['platform']]]></code>
     </MixedAssignment>
   </file>
+  <file src="src/Codec/EncodeIfSupported.php">
+    <InvalidReturnType>
+      <code>($value is NativeType ? BSONType : $value)</code>
+    </InvalidReturnType>
+  </file>
   <file src="src/Collection.php">
     <MixedArgumentTypeCoercion>
       <code>$options</code>
diff --git a/src/Builder/BuilderEncoder.php b/src/Builder/BuilderEncoder.php
index 2f157d793..dc57f7b61 100644
--- a/src/Builder/BuilderEncoder.php
+++ b/src/Builder/BuilderEncoder.php
@@ -55,7 +55,7 @@ public function encode($value): stdClass|array|string
         // A pipeline is encoded as a list of stages
         if ($value instanceof Pipeline) {
             $encoded = [];
-            foreach ($value->stages as $stage) {
+            foreach ($value->getIterator() as $stage) {
                 $encoded[] = $this->encodeIfSupported($stage);
             }
 
diff --git a/src/Builder/Pipeline.php b/src/Builder/Pipeline.php
index 039ff5f8b..19f400eb0 100644
--- a/src/Builder/Pipeline.php
+++ b/src/Builder/Pipeline.php
@@ -2,22 +2,40 @@
 
 namespace MongoDB\Builder;
 
+use ArrayIterator;
+use IteratorAggregate;
 use MongoDB\Builder\Stage\StageInterface;
 use MongoDB\Exception\InvalidArgumentException;
+use Traversable;
 
 use function array_is_list;
+use function array_merge;
 
-class Pipeline
+/** @template-implements IteratorAggregate<StageInterface> */
+class Pipeline implements IteratorAggregate
 {
-    public array $stages;
+    /** @var StageInterface[] */
+    private array $stages = [];
 
-    public function __construct(
-        StageInterface ...$stages
-    ) {
+    public function __construct(StageInterface ...$stages)
+    {
+        $this->add(...$stages);
+    }
+
+    /** @return $this */
+    public function add(StageInterface ...$stages): static
+    {
         if (! array_is_list($stages)) {
             throw new InvalidArgumentException('Expected $stages argument to be a list, got an associative array.');
         }
 
-        $this->stages = $stages;
+        $this->stages = array_merge($this->stages, $stages);
+
+        return $this;
+    }
+
+    public function getIterator(): Traversable
+    {
+        return new ArrayIterator($this->stages);
     }
 }
diff --git a/tests/Builder/BuilderCodecTest.php b/tests/Builder/BuilderCodecTest.php
index d129d5495..dbf6b48e6 100644
--- a/tests/Builder/BuilderCodecTest.php
+++ b/tests/Builder/BuilderCodecTest.php
@@ -16,19 +16,23 @@
 use function array_walk;
 use function is_array;
 
+/**
+ * @todo This annotation is not enough as this PHP file needs to use named arguments, that can't compile on PHP 7.4
+ * @requires PHP 8.0
+ */
 class BuilderCodecTest extends TestCase
 {
+    /** @see https://www.mongodb.com/docs/manual/reference/operator/aggregation/match/#equality-match */
     public function testPipeline(): void
     {
         $pipeline = new Pipeline(
-            Stage::match(Aggregation::eq('$foo', 1)),
-            Stage::match(Aggregation::ne('$foo', 2)),
+            // @todo array is accepted by the stage class, but we expect an object. The driver accepts both.
+            Stage::match((object) ['author' => 'dave']),
             Stage::limit(1),
         );
 
         $expected = [
-            ['$match' => ['$eq' => ['$foo', 1]]],
-            ['$match' => ['$ne' => ['$foo', 2]]],
+            ['$match' => ['author' => 'dave']],
             ['$limit' => 1],
         ];
 
@@ -70,15 +74,16 @@ public function testPerformCount(): void
      * @see https://www.mongodb.com/docs/manual/reference/operator/aggregation/filter/#examples
      * @dataProvider provideAggregationFilterLimit
      */
-    public function testAggregationFilter($limit, $expectedLimit): void
+    public function testAggregationFilter(?int $limit, array $expectedLimit): void
     {
         $pipeline = new Pipeline(
             Stage::project([
                 'items' => Aggregation::filter(
-                    input: Expression::arrayFieldPath('items'),
-                    cond: Aggregation::gte(Expression::variable('item.price'), 100),
-                    as: 'item',
-                    limit: $limit,
+                    // @todo use named argument once we can require PHP 8
+                    Expression::arrayFieldPath('items'),
+                    Aggregation::gte(Expression::variable('item.price'), 100),
+                    'item',
+                    $limit,
                 ),
             ]),
         );