引用：

detail.twig
以下を非表示にしてみたところ、

{{ dump(form.quantity) }}
ここに数量フォーム
{# <div class="ec-numberInput"><span>{{ '数量'|trans }}</span>
{{ form_widget(form.quantity) }}
{{ form_errors(form.quantity) }}
</div> #}


カートボタンとお気に入りボタンの間に以下が表示されました。
Symfony\Component\Form\FormView {#4936 ▼
+vars: array:34 [▼
"value" => "1"
"attr" => array:2 [▼
"min" => 1
"maxlength" => 9
]
"form" => Symfony\Component\Form\FormView {#4936}
"id" => "quantity"
"name" => "quantity"
"full_name" => "quantity"
"disabled" => false
"label" => null
"label_format" => null
"label_html" => false
"multipart" => false
"block_prefixes" => array:3 [▼
0 => "form"
1 => "integer"
2 => "_quantity"
]
"unique_block_prefix" => "_quantity"
"row_attr" => []
"translation_domain" => null
"label_translation_parameters" => []
"attr_translation_parameters" => []
"priority" => 0
"cache_key" => "_quantity_integer"
"errors" => Symfony\Component\Form\FormErrorIterator {#4900 ▶}
"valid" => true
"data" => 1
"required" => true
"size" => null
"label_attr" => []
"help" => null
"help_attr" => []
"help_html" => false
"help_translation_parameters" => []
"compound" => false
"method" => "POST"
"action" => ""
"submitted" => false
"eccube_form_options" => array:3 [▼
"auto_render" => false
"form_theme" => null
"style_class" => "ec-select"
]
]
+parent: Symfony\Component\Form\FormView {#4954 ▼
+vars: array:34 [▶]
+parent: null
+children: array:4 [▶]
-rendered: false
-methodRendered: false
}
+children: []
-rendered: false
-methodRendered: false
}

Quantity
数量を加減するフォーム

フォーム部分は非表示になりませんでした。