Issue 36327: Different validation between attribute creation and update via REST API

app/code/Magento/Catalog/Model/Product/Attribute/Repository.php

@@ -145,9 +145,11 @@ public function save(\Magento\Catalog\Api\Data\ProductAttributeInterface $attrib
             $this->validateCode($attribute->getAttributeCode());
             $this->validateFrontendInput($attribute->getFrontendInput());
 
-            $attribute->setBackendType(
-                $attribute->getBackendTypeByInput($attribute->getFrontendInput())
-            );
+            $backendType = $attribute->getBackendTypeByInput($attribute->getFrontendInput());
+            if ($attribute->getBackendType() && $attribute->getBackendType() !== $backendType) {
+                throw InputException::invalidFieldValue('backend_type', $attribute->getBackendType());
+            }
+            $attribute->setBackendType($backendType);
             $attribute->setSourceModel(
                 $this->productHelper->getAttributeSourceModelByInputType($attribute->getFrontendInput())
             );

app/code/Magento/Catalog/Test/Fixture/MultiselectAttribute.php

@@ -13,6 +13,7 @@ class MultiselectAttribute extends SelectAttribute
 {
     private const DEFAULT_DATA = [
         'frontend_input' => 'multiselect',
+        'backend_type' => 'text'
     ];
 
     /**

app/code/Magento/Catalog/Test/Mftf/Data/ProductAttributeData.xml

@@ -267,7 +267,7 @@
         <data key="is_unique">false</data>
         <data key="is_searchable">false</data>
         <data key="is_visible">true</data>
-        <data key="backend_type">text</data>
+        <data key="backend_type">varchar</data>
         <data key="is_wysiwyg_enabled">false</data>
         <data key="is_visible_in_advanced_search">false</data>
         <data key="is_visible_on_front">true</data>

app/code/Magento/Catalog/Test/Unit/Model/Product/Attribute/RepositoryTest.php

@@ -10,13 +10,12 @@
 
 use Magento\Catalog\Api\Data\ProductAttributeInterface;
 use Magento\Catalog\Api\Data\ProductInterface;
-use Magento\Catalog\Api\ProductAttributeOptionManagementInterface;
 use Magento\Catalog\Helper\Product;
 use Magento\Catalog\Model\Product\Attribute\Repository;
 use Magento\Catalog\Model\ResourceModel\Eav\Attribute;
-use Magento\Eav\Api\AttributeOptionManagementInterface;
 use Magento\Eav\Api\AttributeRepositoryInterface;
 use Magento\Eav\Api\Data\AttributeFrontendLabelInterface;
+use Magento\Eav\Model\Adminhtml\System\Config\Source\Inputtype\Validator;
 use Magento\Eav\Model\Adminhtml\System\Config\Source\Inputtype\ValidatorFactory;
 use Magento\Eav\Model\Config;
 use Magento\Eav\Model\Entity\Attribute\FrontendLabel;
@@ -328,4 +327,39 @@ public function testSaveSavesDefaultFrontendLabelIfItIsPresentInPayload()
 
         $this->model->save($attributeMock);
     }
+
+    /**
+     * @return void
+     */
+    public function testSaveInputExceptionInvalidBackendType()
+    {
+        $this->expectException('Magento\Framework\Exception\InputException');
+        $this->expectExceptionMessage('Invalid value of "decimal" provided for the backend_type field.');
+        $attributeMock = $this->createPartialMock(
+            Attribute::class,
+            [
+                'getFrontendLabels',
+                'getDefaultFrontendLabel',
+                'getAttributeId',
+                'setAttributeId',
+                'getAttributeCode',
+                'getBackendTypeByInput',
+                'getBackendType'
+            ]
+        );
+        $attributeMock->expects($this->once())->method('getAttributeId')->willReturn(null);
+        $attributeMock->expects($this->once())->method('setAttributeId')->with(null)->willReturnSelf();
+        $labelMock = $this->createMock(FrontendLabel::class);
+        $attributeMock->expects($this->any())->method('getFrontendLabels')->willReturn([$labelMock]);
+        $attributeMock->expects($this->any())->method('getDefaultFrontendLabel')->willReturn('default_label');
+        $attributeMock->expects($this->any())->method('getAttributeCode')->willReturn('attribute_code');
+        $attributeMock->expects($this->any())->method('getBackendTypeByInput')->willReturn('varchar');
+        $attributeMock->expects($this->any())->method('getBackendType')->willReturn('decimal');
+
+        $validateMock = $this->createMock(Validator::class);
+        $this->validatorFactoryMock->expects($this->any())->method('create')->willReturn($validateMock);
+        $validateMock->expects($this->any())->method('isValid')->willReturn(true);
+
+        $this->model->save($attributeMock);
+    }
 }

app/code/Magento/ConfigurableProduct/Test/Fixture/Attribute.php

@@ -24,6 +24,7 @@ class Attribute extends \Magento\Catalog\Test\Fixture\Attribute
             ]
         ],
         'scope' => 'global',
+        'backend_type' => 'int'
     ];
 
     /**

app/code/Magento/Weee/Test/Fixture/Attribute.php

@@ -13,6 +13,7 @@ class Attribute extends \Magento\Catalog\Test\Fixture\Attribute
 {
     private const DEFAULT_DATA = [
         'frontend_input' => 'weee',
+        'backend_type' => null
     ];
 
     /**

dev/tests/integration/testsuite/Magento/Catalog/Model/Product/Attribute/Backend/PriceTest.php

@@ -352,9 +352,21 @@ public static function tearDownAfterClass(): void
         DataFixture(StoreGroupFixture::class, ['website_id' => '$website2.id$'], 'store_group2'),
         DataFixture(StoreFixture::class, ['store_group_id' => '$store_group2.id$'], 'store2'),
         DataFixture(StoreFixture::class, ['store_group_id' => '$store_group2.id$'], 'store3'),
-        DataFixture(AttributeFixture::class, ['frontend_input' => 'price', 'is_filterable' => 1], 'attr1'),
-        DataFixture(AttributeFixture::class, ['frontend_input' => 'price', 'is_filterable' => 1], 'attr2'),
-        DataFixture(AttributeFixture::class, ['frontend_input' => 'price', 'is_filterable' => 1], 'attr3'),
+        DataFixture(
+            AttributeFixture::class,
+            ['frontend_input' => 'price', 'backend_type' => 'decimal', 'is_filterable' => 1],
+            'attr1'
+        ),
+        DataFixture(
+            AttributeFixture::class,
+            ['frontend_input' => 'price', 'backend_type' => 'decimal', 'is_filterable' => 1],
+            'attr2'
+        ),
+        DataFixture(
+            AttributeFixture::class,
+            ['frontend_input' => 'price', 'backend_type' => 'decimal', 'is_filterable' => 1],
+            'attr3'
+        ),
         DataFixture(ProductFixture::class, ['website_ids' => [1, '$website2.id']], 'product'),
     ]
     public function testSaveCustomPriceAttribute(

dev/tests/integration/testsuite/Magento/Elasticsearch/Model/Indexer/Fulltext/Plugin/Category/Product/AttributeTest.php

@@ -176,7 +176,7 @@ private function getAttributeData(): array
             'used_in_product_listing'       => 1,
             'used_for_sort_by'              => 0,
             'frontend_label'                => ['Drop-Down Attribute'],
-            'backend_type'                  => 'varchar',
+            'backend_type'                  => 'int',
             'option'                        => [
                 'value' => [
                     'option_1' => ['Option 1'],