Reselect的劣势有哪些？何时不应使用Reselect？

Great question—you’re absolutely right that no library is a universal "must-have." Reselect is fantastic for solving specific state computation problems, but it’s not without its downsides. Let’s break them down, along with scenarios where you’re better off avoiding it.

Key Disadvantages of Reselect #

• Unnecessary complexity for simple state reads
  If you only need to fetch a straightforward value from your state (like state.cart.itemsCount), wrapping that in a Reselect selector adds unnecessary boilerplate. What could be a one-line access turns into a multi-line selector definition, making your code more verbose and harder to follow—especially for team members new to the library.
• Cache invalidation pitfalls
  Reselect’s memoization relies on reference equality for its input arguments. If you accidentally pass a newly created object or array (e.g., filter(state.items, x => x.active) that returns a new array every time), the cache will break, and your selector will recompute on every render. This not only negates performance benefits but can also introduce hard-to-debug performance issues.
• Learning curve for advanced use cases
  Basic selectors are easy enough, but mastering more advanced patterns—like composing selectors, handling async data, or creating dynamic selectors that accept parameters—takes time. If your team is already stretched thin, the time spent learning and debugging these patterns might not be worth the payoff.
• Overhead for small or simple apps
  For tiny apps with minimal state or infrequent state updates, Reselect’s performance gains are negligible. You’ll be adding an extra dependency (and slightly increasing your bundle size) for a tool that doesn’t solve any meaningful problems in your context.

When to Avoid Reselect #

• You’re only accessing raw state values
  Skip Reselect if you don’t need to transform or compute derived data—just grab the value directly from the state. It’s faster to write and easier to maintain.
• Your data rarely changes
  If the piece of state you’re accessing updates once a day (or less), memoization won’t give you any noticeable benefits. Save yourself the boilerplate.
• Your team lacks familiarity with it (and time to learn)
  If your team hasn’t used Reselect before and you’re on a tight deadline, introducing it can lead to more bugs and slower development. Stick to simpler patterns until you have time to onboard everyone properly.
• You’re working with dynamic data that has frequent reference changes
  If your selector depends on values that are recreated on every render (like inline objects or arrays), Reselect’s cache will never work as intended. In this case, you’re better off computing the value directly or finding a different way to stabilize your inputs.

At the end of the day, Reselect is a powerful tool—but like any tool, it’s only useful when applied to the right problem. Don’t feel pressured to use it just because everyone else does.

内容的提问来源于stack exchange，提问作者Arseniy-II