From 179c6a6fe589d6721ca0d12072e0502de402b796 Mon Sep 17 00:00:00 2001
From: Jacques Florian <florian.jacques.dev@gmail.com>
Date: Tue, 9 Jul 2024 15:14:18 +0200
Subject: [PATCH] Add document version feature (#3021)
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Co-authored-by: Jérôme Tamarelle <jerome@tamarelle.net>
---
 CHANGELOG.md                      |  5 +-
 src/Eloquent/HasSchemaVersion.php | 82 +++++++++++++++++++++++++++++++
 tests/Models/SchemaVersion.php    | 26 ++++++++++
 tests/SchemaVersionTest.php       | 58 ++++++++++++++++++++++
 4 files changed, 169 insertions(+), 2 deletions(-)
 create mode 100644 src/Eloquent/HasSchemaVersion.php
 create mode 100644 tests/Models/SchemaVersion.php
 create mode 100644 tests/SchemaVersionTest.php

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 777a22304..5f2a2f9e5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,9 +1,10 @@
 # Changelog
 All notable changes to this project will be documented in this file.
 
-## [4.6.0] - upcoming
+## [4.6.0] - 2024-07-09
 
-* Add `DocumentTrait` to use any 3rd party model with MongoDB @GromNaN in [#2580](https://github.com/mongodb/laravel-mongodb/pull/2580)
+* Add `DocumentModel` trait to use any 3rd party model with MongoDB @GromNaN in [#2580](https://github.com/mongodb/laravel-mongodb/pull/2580)
+* Add `HasSchemaVersion` trait to help implementing the [schema versioning pattern](https://www.mongodb.com/docs/manual/tutorial/model-data-for-schema-versioning/) @florianJacques in [#3021](https://github.com/mongodb/laravel-mongodb/pull/3021)
 * Add support for Closure for Embed pagination @GromNaN in [#3027](https://github.com/mongodb/laravel-mongodb/pull/3027)
 
 ## [4.5.0] - 2024-06-20
diff --git a/src/Eloquent/HasSchemaVersion.php b/src/Eloquent/HasSchemaVersion.php
new file mode 100644
index 000000000..8849f655a
--- /dev/null
+++ b/src/Eloquent/HasSchemaVersion.php
@@ -0,0 +1,82 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MongoDB\Laravel\Eloquent;
+
+use Error;
+use LogicException;
+
+use function sprintf;
+
+/**
+ * Use this trait to implement schema versioning in your models. The document
+ * is updated automatically when its schema version retrieved from the database
+ * is lower than the current schema version of the model.
+ *
+ *     class MyVersionedModel extends Model
+ *     {
+ *         use HasSchemaVersion;
+ *
+ *         public const int SCHEMA_VERSION = 1;
+ *
+ *         public function migrateSchema(int $fromVersion): void
+ *         {
+ *             // Your logic to update the document to the current schema version
+ *         }
+ *     }
+ *
+ * @see https://www.mongodb.com/docs/manual/tutorial/model-data-for-schema-versioning/
+ *
+ * Requires PHP 8.2+
+ */
+trait HasSchemaVersion
+{
+    /**
+     * This method should be implemented in the model to migrate a document from
+     * an older schema version to the current schema version.
+     */
+    public function migrateSchema(int $fromVersion): void
+    {
+    }
+
+    public static function bootHasSchemaVersion(): void
+    {
+        static::saving(function ($model) {
+            if ($model->getAttribute($model::getSchemaVersionKey()) === null) {
+                $model->setAttribute($model::getSchemaVersionKey(), $model->getModelSchemaVersion());
+            }
+        });
+
+        static::retrieved(function (self $model) {
+            $version = $model->getSchemaVersion();
+
+            if ($version < $model->getModelSchemaVersion()) {
+                $model->migrateSchema($version);
+                $model->setAttribute($model::getSchemaVersionKey(), $model->getModelSchemaVersion());
+            }
+        });
+    }
+
+    /**
+     * Get Current document version, fallback to 0 if not set
+     */
+    public function getSchemaVersion(): int
+    {
+        return $this->{static::getSchemaVersionKey()} ?? 0;
+    }
+
+    protected static function getSchemaVersionKey(): string
+    {
+        return 'schema_version';
+    }
+
+    protected function getModelSchemaVersion(): int
+    {
+        try {
+            return $this::SCHEMA_VERSION;
+        } catch (Error) {
+            throw new LogicException(sprintf('Constant %s::SCHEMA_VERSION is required when using HasSchemaVersion', $this::class));
+        }
+    }
+}
diff --git a/tests/Models/SchemaVersion.php b/tests/Models/SchemaVersion.php
new file mode 100644
index 000000000..cacfc3f65
--- /dev/null
+++ b/tests/Models/SchemaVersion.php
@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MongoDB\Laravel\Tests\Models;
+
+use MongoDB\Laravel\Eloquent\HasSchemaVersion;
+use MongoDB\Laravel\Eloquent\Model as Eloquent;
+
+class SchemaVersion extends Eloquent
+{
+    use HasSchemaVersion;
+
+    public const SCHEMA_VERSION = 2;
+
+    protected $connection       = 'mongodb';
+    protected $collection       = 'documentVersion';
+    protected static $unguarded = true;
+
+    public function migrateSchema(int $fromVersion): void
+    {
+        if ($fromVersion < 2) {
+            $this->age = 35;
+        }
+    }
+}
diff --git a/tests/SchemaVersionTest.php b/tests/SchemaVersionTest.php
new file mode 100644
index 000000000..dfe2f5122
--- /dev/null
+++ b/tests/SchemaVersionTest.php
@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MongoDB\Laravel\Tests;
+
+use Illuminate\Support\Facades\DB;
+use LogicException;
+use MongoDB\Laravel\Eloquent\HasSchemaVersion;
+use MongoDB\Laravel\Eloquent\Model;
+use MongoDB\Laravel\Tests\Models\SchemaVersion;
+
+class SchemaVersionTest extends TestCase
+{
+    public function tearDown(): void
+    {
+        SchemaVersion::truncate();
+    }
+
+    public function testWithBasicDocument()
+    {
+        $document = new SchemaVersion(['name' => 'Luc']);
+        $this->assertEmpty($document->getSchemaVersion());
+        $document->save();
+
+        // The current schema version of the model is stored by default
+        $this->assertEquals(2, $document->getSchemaVersion());
+
+        // Test automatic migration
+        SchemaVersion::insert([
+            ['name' => 'Vador', 'schema_version' => 1],
+        ]);
+        $document = SchemaVersion::where('name', 'Vador')->first();
+        $this->assertEquals(2, $document->getSchemaVersion());
+        $this->assertEquals(35, $document->age);
+
+        $document->save();
+
+        // The migrated version is saved
+        $data = DB::connection('mongodb')
+            ->collection('documentVersion')
+            ->where('name', 'Vador')
+            ->get();
+
+        $this->assertEquals(2, $data[0]['schema_version']);
+    }
+
+    public function testIncompleteImplementation(): void
+    {
+        $this->expectException(LogicException::class);
+        $this->expectExceptionMessage('::SCHEMA_VERSION is required when using HasSchemaVersion');
+        $document = new class extends Model {
+            use HasSchemaVersion;
+        };
+
+        $document->save();
+    }
+}