👀 Views: 86 💬 Answers: 1 📅 Created: 2025-07-23

ruby rails activerecord enumerable Ruby

I'm relatively new to this, so bear with me... I recently switched to This might be a silly question, but I'm working with an scenario where using `Enumerable#map` on an ActiveRecord relation seems to be returning unexpected nil values... I'm working with Ruby 3.1 and Rails 7, and I have a model called `User` that has many associated `Posts`. Here’s the code snippet where the question occurs: ```ruby users = User.includes(:posts).where(active: true) user_titles = users.map { |user| user.posts.map(&:title) } ``` In the above code, I'm trying to get an array of titles for all active users. However, I noticed that some of the user entries in `user_titles` are returning nil values, especially for users who have no posts. I expected to get an empty array for those users instead of nil. To troubleshoot this, I tried using `compact`: ```ruby user_titles = users.map { |user| user.posts.map(&:title) }.compact ``` However, this didn't resolve the scenario, and I'm still getting nil in the final array. I also checked the data in the database to ensure that the `posts` association is set up correctly and that there are indeed users without posts. Another approach I tried was using `flat_map`: ```ruby user_titles = users.flat_map { |user| user.posts.map(&:title) } ``` This correctly flattens the array but still results in nil values for users without posts. Is there a better way to handle this situation so that I can avoid nil values in my resulting array? Any insights or best practices would be appreciated! This is part of a larger application I'm building. This is my first time working with Ruby stable. What's the best practice here? I'm using Ruby LTS in this project.