Implement NoDownMethodRule for Laravel and Phinx (#1)

Author: apostergiakis

README.md

@@ -108,3 +108,17 @@ Ensures each migration creates at most one table.
 |---|---|
 | [Phinx](./src/Rules/Phinx/ForbidMultipleTableCreationsRule.php) | Multiple calls to `create()` on table instances |
 | [Laravel](./src/Rules/Laravel/ForbidMultipleTableCreationsRule.php) | Multiple `Schema::create()` calls in the same migration |
+
+---
+
+### Rule: `NoDownMethodRule`
+Forbids the usage of the `down` method in migrations.
+> Useful for teams that prefer forward-only migrations or rely solely on the `change` method for extensive rollback support where possible.
+
+#### Support
+
+| Framework | Forbidden usage |
+|---|---|
+| [Phinx](./src/Rules/Phinx/NoDownMethodRule.php) | `public function down(): void` |
+| [Laravel](./src/Rules/Laravel/NoDownMethodRule.php) | `public function down(): void` |
+

extension.neon

@@ -7,13 +7,15 @@ parametersSchema:
             forbidEnumColumn: bool()
             forbidRawSql: bool()
             forbidMultipleTableCreations: bool()
+            forbidDown: bool()
         ])
         laravel: structure([
             enforceCollation: bool()
             forbidAfter: bool()
             forbidEnumColumn: bool()
             forbidRawSql: bool()
             forbidMultipleTableCreations: bool()
+            forbidDown: bool()
         ])
     ])
 
@@ -26,12 +28,14 @@ parameters:
             forbidEnumColumn: false
             forbidRawSql: false
             forbidMultipleTableCreations: true
+            forbidDown: false
         laravel:
             enforceCollation: true
             forbidAfter: true
             forbidEnumColumn: false
             forbidRawSql: false
             forbidMultipleTableCreations: true
+            forbidDown: false
 
 conditionalTags:
     PhpStanMigrationRules\Rules\Phinx\EnforceCollationRule:
@@ -44,6 +48,8 @@ conditionalTags:
         phpstan.rules.rule: %migrationRules.phinx.forbidRawSql%
     PhpStanMigrationRules\Rules\Phinx\ForbidMultipleTableCreationsRule:
         phpstan.rules.rule: %migrationRules.phinx.forbidMultipleTableCreations%
+    PhpStanMigrationRules\Rules\Phinx\NoDownMethodRule:
+        phpstan.rules.rule: %migrationRules.phinx.forbidDown%
     PhpStanMigrationRules\Rules\Laravel\EnforceCollationRule:
         phpstan.rules.rule: %migrationRules.laravel.enforceCollation%
     PhpStanMigrationRules\Rules\Laravel\ForbidAfterRule:
@@ -54,6 +60,8 @@ conditionalTags:
         phpstan.rules.rule: %migrationRules.laravel.forbidRawSql%
     PhpStanMigrationRules\Rules\Laravel\ForbidMultipleTableCreationsRule:
         phpstan.rules.rule: %migrationRules.laravel.forbidMultipleTableCreations%
+    PhpStanMigrationRules\Rules\Laravel\NoDownMethodRule:
+        phpstan.rules.rule: %migrationRules.laravel.forbidDown%
 
 services:
     -
@@ -73,6 +81,9 @@ services:
     -
         class: PhpStanMigrationRules\Rules\Phinx\ForbidMultipleTableCreationsRule
 
+    -
+        class: PhpStanMigrationRules\Rules\Phinx\NoDownMethodRule
+
     -
         class: PhpStanMigrationRules\Rules\Laravel\EnforceCollationRule
         arguments:
@@ -89,3 +100,6 @@ services:
 
     -
         class: PhpStanMigrationRules\Rules\Laravel\ForbidMultipleTableCreationsRule
+
+    -
+        class: PhpStanMigrationRules\Rules\Laravel\NoDownMethodRule

src/Rules/Laravel/NoDownMethodRule.php

@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpStanMigrationRules\Rules\Laravel;
+
+use PhpParser\Node;
+use PhpParser\Node\Stmt\ClassMethod;
+use PHPStan\Analyser\Scope;
+use PHPStan\Rules\RuleErrorBuilder;
+
+/**
+ * @extends LaravelRule<ClassMethod>
+ */
+final class NoDownMethodRule extends LaravelRule
+{
+    private const string RULE_IDENTIFIER = 'laravel.schema.noDownMethod';
+
+    private const string MESSAGE =
+        'Forbidden: "down" method. '
+        . 'Why: a "down" method enables rollbacks, which can cause data loss and break forward-only migration strategies. '
+        . 'Fix: use the "change" method for reversible migrations, or omit the rollback path entirely.';
+
+    public function getNodeType(): string
+    {
+        return ClassMethod::class;
+    }
+
+    public function processNode(Node $node, Scope $scope): array
+    {
+        if (!$this->isLaravelMigration($scope)) {
+            return [];
+        }
+
+        if ($node->name->toString() !== 'down') {
+            return [];
+        }
+
+        if (!$node->isPublic()) {
+            return [];
+        }
+
+        return [
+            RuleErrorBuilder::message(self::MESSAGE)
+                ->identifier(self::RULE_IDENTIFIER)
+                ->build(),
+        ];
+    }
+}

src/Rules/Phinx/NoDownMethodRule.php

@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpStanMigrationRules\Rules\Phinx;
+
+use PhpParser\Node;
+use PhpParser\Node\Stmt\ClassMethod;
+use PHPStan\Analyser\Scope;
+use PHPStan\Rules\RuleErrorBuilder;
+
+/**
+ * @extends PhinxRule<ClassMethod>
+ */
+final class NoDownMethodRule extends PhinxRule
+{
+    private const string RULE_IDENTIFIER = 'phinx.schema.noDownMethod';
+
+    private const string MESSAGE =
+        'Forbidden: "down" method. '
+        . 'Why: a "down" method enables rollbacks, which can cause data loss and break forward-only migration strategies. '
+        . 'Fix: use the "change" method for reversible migrations, or omit the rollback path entirely.';
+
+    public function getNodeType(): string
+    {
+        return ClassMethod::class;
+    }
+
+    public function processNode(Node $node, Scope $scope): array
+    {
+        if (!$this->isPhinxMigration($scope)) {
+            return [];
+        }
+
+        if ($node->name->toString() !== 'down') {
+            return [];
+        }
+
+        if (!$node->isPublic()) {
+            return [];
+        }
+
+        return [
+            RuleErrorBuilder::message(self::MESSAGE)
+                ->identifier(self::RULE_IDENTIFIER)
+                ->build(),
+        ];
+    }
+}

tests/Rules/Laravel/NoDownMethodRuleTest.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpStanMigrationRules\Tests\Rules\Laravel;
+
+use PhpStanMigrationRules\Rules\Laravel\NoDownMethodRule;
+use PHPStan\Rules\Rule;
+use PHPStan\Testing\RuleTestCase;
+
+/**
+ * @extends RuleTestCase<NoDownMethodRule>
+ */
+final class NoDownMethodRuleTest extends RuleTestCase
+{
+    protected function getRule(): Rule
+    {
+        return new NoDownMethodRule();
+    }
+
+    public function testReportsDownMethod(): void
+    {
+        $this->analyse(
+            [__DIR__ . '/fixtures/NoDownMethod.php'],
+            [
+                [
+                    'Forbidden: "down" method. Why: a "down" method enables rollbacks, which can cause data loss and break forward-only migration strategies. Fix: use the "change" method for reversible migrations, or omit the rollback path entirely.',
+                    11,
+                ],
+            ]
+        );
+    }
+
+    public function testReportsDownMethodInAnonymousClass(): void
+    {
+        $this->analyse(
+            [__DIR__ . '/fixtures/NoDownMethodAnonymous.php'],
+            [
+                [
+                    'Forbidden: "down" method. Why: a "down" method enables rollbacks, which can cause data loss and break forward-only migration strategies. Fix: use the "change" method for reversible migrations, or omit the rollback path entirely.',
+                    11,
+                ],
+            ]
+        );
+    }
+
+    public function testDoesNotReportChangeMethod(): void
+    {
+        $this->analyse(
+            [__DIR__ . '/fixtures/WithChangeMethod.php'],
+            []
+        );
+    }
+}

tests/Rules/Laravel/fixtures/NoDownMethod.php

@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpStanMigrationRules\Tests\Rules\Laravel\fixtures;
+
+use Illuminate\Database\Migrations\Migration;
+
+class NoDownMethod extends Migration
+{
+    public function down(): void
+    {
+        // ...
+    }
+}

tests/Rules/Laravel/fixtures/NoDownMethodAnonymous.php

@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpStanMigrationRules\Tests\Rules\Laravel\fixtures;
+
+use Illuminate\Database\Migrations\Migration;
+
+return new class extends Migration
+{
+    public function down(): void
+    {
+        // ...
+    }
+};

tests/Rules/Laravel/fixtures/WithChangeMethod.php

@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpStanMigrationRules\Tests\Rules\Laravel\fixtures;
+
+use Illuminate\Database\Migrations\Migration;
+
+class WithChangeMethod extends Migration
+{
+    public function change(): void
+    {
+        // ...
+    }
+}

tests/Rules/Phinx/NoDownMethodRuleTest.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpStanMigrationRules\Tests\Rules\Phinx;
+
+use PhpStanMigrationRules\Rules\Phinx\NoDownMethodRule;
+use PHPStan\Rules\Rule;
+use PHPStan\Testing\RuleTestCase;
+
+/**
+ * @extends RuleTestCase<NoDownMethodRule>
+ */
+final class NoDownMethodRuleTest extends RuleTestCase
+{
+    protected function getRule(): Rule
+    {
+        return new NoDownMethodRule();
+    }
+
+    public function testReportsDownMethod(): void
+    {
+        $this->analyse(
+            [__DIR__ . '/fixtures/NoDownMethod.php'],
+            [
+                [
+                    'Forbidden: "down" method. Why: a "down" method enables rollbacks, which can cause data loss and break forward-only migration strategies. Fix: use the "change" method for reversible migrations, or omit the rollback path entirely.',
+                    11,
+                ],
+            ]
+        );
+    }
+
+    public function testDoesNotReportChangeMethod(): void
+    {
+        $this->analyse(
+            [__DIR__ . '/fixtures/WithChangeMethod.php'],
+            []
+        );
+    }
+}

tests/Rules/Phinx/fixtures/NoDownMethod.php

@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpStanMigrationRules\Tests\Rules\Phinx\fixtures;
+
+use Phinx\Migration\AbstractMigration;
+
+class NoDownMethod extends AbstractMigration
+{
+    public function down(): void
+    {
+        // ...
+    }
+}