addNewField example

$response = $this->getBrowser()->getResponse();
        static::assertSame(Response::HTTP_OK, $response->getStatusCode(), (string) $response->getContent());

        $data = json_decode((string) $response->getContent(), true, 512, \JSON_THROW_ON_ERROR);
        static::assertEquals(15, $data['data']['attributes']['taxRate']);
    }

    public function testWriteExtensionWithExtensionKey(): void
    {
        $field = (new OneToManyAssociationField('testSeoUrls', SeoUrlDefinition::class, 'sales_channel_id'))->addFlags(new ApiAware(), new Extension());

        $this->getContainer()->get(SalesChannelDefinition::class)->getFields()->addNewField($field);

        $salesChannelId = Uuid::randomHex();
        $this->createSalesChannel($salesChannelId);

        $data = [
            'extensions' => [
                'testSeoUrls' => [
                    [
                        'languageId' => Defaults::LANGUAGE_SYSTEM,
                        'foreignKey' => $salesChannelId,
                        'routeName' => 'test',
                        

public function testICanWriteAndReadManyToOneAssociationExtension(): void
    {
        $this->connection->rollBack();

        try {
            $this->connection->executeStatement('ALTER TABLE `product` ADD COLUMN my_tax_id binary(16) NULL');
        } catch (Exception) {
        }

        $this->connection->beginTransaction();

        $this->getContainer()->get(ProductDefinition::class)->getFields()->addNewField(
            (new ManyToOneAssociationField('myTax', 'my_tax_id', TaxDefinition::class, 'id'))->addFlags(new ApiAware(), new Extension())
        );
        $this->getContainer()->get(ProductDefinition::class)->getFields()->addNewField(
            (new FkField('my_tax_id', 'myTaxId', TaxDefinition::class))->addFlags(new ApiAware(), new Extension())
        );

        $id = Uuid::randomHex();

        $data = [
            'id' => $id,
            'name' => 'test',