Support for cascade, set null, restrict, and no action for onDelete actions (#230)

Author: Nathan Esayeas

config/blueprint.php

@@ -94,4 +94,24 @@
     */
 
     'use_guarded' => false,
+
+    /*
+    |--------------------------------------------------------------------------
+    | Foreign Key ON DELETE action
+    |--------------------------------------------------------------------------
+    |
+    | By default, Blueprint will set the `ON DELETE` action to 'cascade'.
+    |
+    | restrict / no action:
+    |   - No action is performed with the child data when the parent data is deleted.
+    | cascade:
+    |   - The child data is either deleted when the parent data is deleted.
+    | set null:
+    |   - The child data is set to NULL when the parent data is deleted.
+    |
+    | Supported: 'cascade', 'set_null', 'restrict', 'no_action'
+    |
+    */
+
+    'on_delete' => 'cascade',
 ];

src/Generators/MigrationGenerator.php

@@ -17,6 +17,13 @@ class MigrationGenerator implements Generator
         'uuidMorphs',
     ];
 
+    const ON_DELETE_CLAUSES = [
+        'cascade' => "->onDelete('cascade')",
+        'restrict' => "->onDelete('restrict')",
+        'set_null' => "->onDelete('set null')",
+        'no_action' => "->onDelete('no action')",
+    ];
+
     const UNSIGNABLE_TYPES = [
         'bigInteger',
         'decimal',
@@ -148,7 +155,9 @@ protected function buildDefinition(Model $model)
 
                 // TODO: unset the proper modifier
                 $modifiers = collect($modifiers)->reject(function ($modifier) {
-                    return ((is_array($modifier) && key($modifier) === 'foreign')
+                    return (
+                        (is_array($modifier) && key($modifier) === 'foreign')
+                        || (is_array($modifier) && key($modifier) === 'onDelete')
                         || $modifier === 'foreign'
                         || ($modifier === 'nullable' && $this->isLaravel7orNewer()));
                 });
@@ -231,22 +240,29 @@ protected function buildForeignKey(string $column_name, ?string $on, string $typ
             $table = Str::lower(Str::plural($attributes[0]));
         }
 
+        $on_delete_clause = config('blueprint.on_delete', 'cascade');
+
+        $on_delete_suffix = self::ON_DELETE_CLAUSES[$on_delete_clause];
+
         if ($this->isLaravel7orNewer() && $type === 'id') {
             $prefix = in_array('nullable', $modifiers)
                 ? '$table->foreignId' . "('{$column_name}')->nullable()"
                 : '$table->foreignId' . "('{$column_name}')";
 
+            if ($on_delete_clause === 'cascade') {
+                $on_delete_suffix = '->cascadeOnDelete()';
+            }
             if ($column_name === Str::singular($table) . '_' . $column) {
-                return self::INDENT . "{$prefix}->constrained()->cascadeOnDelete()";
+                return self::INDENT . "{$prefix}->constrained(){$on_delete_suffix}";
             }
             if ($column === 'id') {
-                return self::INDENT . "{$prefix}->constrained('{$table}')->cascadeOnDelete()";
+                return self::INDENT . "{$prefix}->constrained('{$table}'){$on_delete_suffix}";
             }
 
-            return self::INDENT . "{$prefix}->constrained('{$table}', '{$column}')->cascadeOnDelete()";
+            return self::INDENT . "{$prefix}->constrained('{$table}', '{$column}'){$on_delete_suffix}";
         }
 
-        return self::INDENT . '$table->foreign' . "('{$column_name}')->references('{$column}')->on('{$table}')->onDelete('cascade')";
+        return self::INDENT . '$table->foreign' . "('{$column_name}')->references('{$column}')->on('{$table}'){$on_delete_suffix}";
     }
 
     protected function getClassName(Model $model)

src/Lexers/ModelLexer.php

@@ -94,6 +94,7 @@ class ModelLexer implements Lexer
         'index' => 'index',
         'primary' => 'primary',
         'foreign' => 'foreign',
+        'ondelete' => 'onDelete',
     ];
 
     public function analyze(array $tokens): array

tests/Feature/Generator/MigrationGeneratorTest.php

@@ -395,6 +395,8 @@ public function output_does_not_duplicate_pivot_table_migration_laravel6()
      */
     public function output_creates_foreign_keys_with_nullable_chained_correctly()
     {
+        $this->app->config->set('blueprint.on_delete', 'set_null');
+
         $this->files->expects('stub')
             ->with('migration.stub')
             ->andReturn(file_get_contents('stubs/migration.stub'));
@@ -419,6 +421,8 @@ public function output_creates_foreign_keys_with_nullable_chained_correctly()
      */
     public function output_creates_foreign_keys_with_nullable_chained_correctly_laravel6()
     {
+        $this->app->config->set('blueprint.on_delete', 'set_null');
+
         $app = \Mockery::mock();
         $app->shouldReceive('version')
             ->withNoArgs()

tests/fixtures/migrations/nullable-chaining-laravel6.php

@@ -17,7 +17,7 @@ public function up()
             $table->bigIncrements('id');
             $table->string('name');
             $table->unsignedBigInteger('user_id')->nullable();
-            $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
+            $table->foreign('user_id')->references('id')->on('users')->onDelete('set null');
             $table->timestamps();
         });
     }

tests/fixtures/migrations/nullable-chaining.php

@@ -16,7 +16,7 @@ public function up()
         Schema::create('carts', function (Blueprint $table) {
             $table->id();
             $table->string('name');
-            $table->foreignId('user_id')->nullable()->constrained()->cascadeOnDelete();
+            $table->foreignId('user_id')->nullable()->constrained()->onDelete('set null');
             $table->timestamps();
         });
     }