ledsun https://blog.hatena.ne.jp/ledsun/ @ledsun blog https://ledsun.hatenablog.com/ Rails 技 空文字を許容するのかしないのか混乱したので、メモっておきます。 my-app(dev):002> params = ActionController::Parameters.new(a: "") => #<ActionController::Parameters {"a" => ""} permitted: false> my-app:003(dev)> params.expect :a (my-app):3:in '<main>': param is missing or the value is empty or invalid: a (ActionController::Paramete… 190 <iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Fledsun.hatenablog.com%2Fentry%2F2025%2F11%2F22%2F224533" title="strong parameterのexpectで空文字はエラー - @ledsun blog" class="embed-card embed-blogcard" scrolling="no" frameborder="0" style="display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;"></iframe> Hatena Blog https://hatena.blog 2025-11-22 22:45:33 rich https://ledsun.hatenablog.com/entry/2025/11/22/224533 1.0 100%