The behavior of StringifyKeys in the upcoming version of Rails has changed.

A new Rails update fixes how the stringify_keys handles different types of hash keys. This change makes the code more reliable and consistent.

The Problem

Rails has a special type of hash called HashWithIndifferentAccess. In the past, it had a quirk. When you used the stringify_keys method, it would only turn symbol keys into strings. Other types of keys, like numbers, stayed the same.

The Fix

The new version changes this behavior. Now, stringify_keys turns all keys into strings, no matter what type they were before. Let's look at an example:

# Old behavior:
# The number 1 stayed as a number
{ 1 => 2 }.with_indifferent_access.stringify_keys[1]     # => 2

# New behavior:
# The number 1 becomes the string "1"
{ 1 => 2 }.with_indifferent_access.stringify_keys["1"]   # => 2

Why This Matters

Think of hash keys like labels on file folders. The old system would only rename some folders but not others. This could lead to confusion. The new system renames all folders in the same way, making it easier to find what you need.

Planning Your Update

This change only comes with major Rails releases. If your code depends on the old behavior, you'll need to plan your update carefully. The Rails team made this choice to prevent breaking existing applications.

Looking Forward

Jean Boussier created this fix to make Rails more dependable. While the old behavior worked for many years, the new version follows a clearer, more logical pattern.

Would you like me to explain any part of this change in more detail?