PHPLIB-1340 Add tests on Projection Operators

Author: GromNaN

generator/config/projection/elemMatch.yaml

@@ -11,3 +11,30 @@ arguments:
         name: query
         type:
             - query
+tests:
+    -
+        name: 'Zipcode Search'
+        link: 'https://www.mongodb.com/docs/manual/reference/operator/projection/elemMatch/#zipcode-search'
+        pipeline:
+            -
+                $match:
+                    zipcode: '63109'
+            -
+                $project:
+                    students:
+                        $elemMatch:
+                            school: 102
+    -
+        name: 'with Multiple Fields'
+        link: 'https://www.mongodb.com/docs/manual/reference/operator/projection/elemMatch/#with-multiple-fields'
+        pipeline:
+            -
+                $match:
+                    zipcode: '63109'
+            -
+                $project:
+                    students:
+                        $elemMatch:
+                            school: 102
+                            age:
+                                $gt: 10

generator/config/projection/filter.yaml

@@ -15,3 +15,41 @@ arguments:
         name: skip
         type:
             - int
+        optional: true
+tests:
+    -
+        name: 'Return an Array with Its First 3 Elements'
+        link: 'https://www.mongodb.com/docs/manual/reference/operator/projection/slice/#return-an-array-with-its-first-3-elements'
+        pipeline:
+            -
+                $project:
+                    comments:
+                        # Example uses the short form, the builder always generated the verbose form
+                        # $slice: 3
+                        $slice: [3]
+    -
+        name: 'Return an Array with Its Last 3 Elements'
+        link: 'https://www.mongodb.com/docs/manual/reference/operator/projection/slice/#return-an-array-with-its-last-3-elements'
+        pipeline:
+            -
+                $project:
+                    comments:
+                        # Example uses the short form, the builder always generated the verbose form
+                        # $slice: -3
+                        $slice: [-3]
+    -
+        name: 'Return an Array with 3 Elements After Skipping the First Element'
+        link: 'https://www.mongodb.com/docs/manual/reference/operator/projection/slice/#return-an-array-with-3-elements-after-skipping-the-first-element'
+        pipeline:
+            -
+                $project:
+                    comments:
+                        $slice: [1, 3]
+    -
+        name: 'Return an Array with 3 Elements After Skipping the Last Element'
+        link: 'https://www.mongodb.com/docs/manual/reference/operator/projection/slice/#return-an-array-with-3-elements-after-skipping-the-last-element'
+        pipeline:
+            -
+                $project:
+                    comments:
+                        $slice: [-1, 3]

generator/config/projection/slice.yaml

@@ -10,7 +10,6 @@
 use MongoDB\Builder\BuilderEncoder;
 use MongoDB\Builder\Expression;
 use MongoDB\Builder\Pipeline;
-use MongoDB\Builder\Projection;
 use MongoDB\Builder\Query;
 use MongoDB\Builder\Stage;
 use MongoDB\Builder\Variable;
@@ -157,7 +156,7 @@ public function testExpressionFilter(array $limit, array $expectedLimit): void
     {
         $pipeline = new Pipeline(
             Stage::project(
-                items: Projection::filter(
+                items: Expression::filter(
                     ...$limit,
                     input: Expression::arrayFieldPath('items'),
                     cond: Expression::gte(Expression::variable('item.price'), 100),

src/Builder/Projection/FactoryTrait.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MongoDB\Tests\Builder\Projection;
+
+use MongoDB\Builder\Pipeline;
+use MongoDB\Builder\Projection;
+use MongoDB\Builder\Query;
+use MongoDB\Builder\Stage;
+use MongoDB\Tests\Builder\PipelineTestCase;
+
+/**
+ * Test $elemMatch projection
+ */
+class ElemMatchOperatorTest extends PipelineTestCase
+{
+    public function testWithMultipleFields(): void
+    {
+        $pipeline = new Pipeline(
+            Stage::match(
+                zipcode: '63109',
+            ),
+            Stage::project(
+                students: Projection::elemMatch(
+                    Query::query(
+                        school: 102,
+                        age: Query::gt(10),
+                    ),
+                ),
+            ),
+        );
+
+        $this->assertSamePipeline(Pipelines::ElemMatchWithMultipleFields, $pipeline);
+    }
+
+    public function testZipcodeSearch(): void
+    {
+        $pipeline = new Pipeline(
+            Stage::match(
+                zipcode: '63109',
+            ),
+            Stage::project(
+                students: Projection::elemMatch(
+                    Query::query(
+                        school: 102,
+                    ),
+                ),
+            ),
+        );
+
+        $this->assertSamePipeline(Pipelines::ElemMatchZipcodeSearch, $pipeline);
+    }
+}