Q: Hashie vs ActiveSupport Hash extensions for Rails projects?

Hashie offers more specialized features like Dash for structured data and deep operations, while ActiveSupport is better integrated with Rails but less modular. Choose Hashie for complex hash manipulation outside Rails core.

Q: Can Hashie handle boolean coercion in hashes?

Yes, but not natively—you must use a custom coercion proc since Ruby lacks a built-in boolean type. The README shows an example with a lambda to coerce strings or numbers to booleans.

Q: What's the difference between Mash and Dash in Hashie?

Mash is a flexible pseudo-object with method access and indifferent keys, while Dash enforces defined properties with requirements and defaults. Use Mash for dynamic data, Dash for structured models.

Q: How to avoid memory leaks with Hashie on older Ruby?

Avoid SymbolizeKeys extension on Rubies pre-2.0, as symbols aren't garbage-collected. Stick to string keys or use KeepOriginalKeys to prevent unintended symbol generation from user input.

Q: Does Hashie work with Rails strong parameters?

Not directly—you need the hashie-forbidden_attributes gem for compatibility. The README notes this for Dash and Mash when used in Rails 4+ contexts.

Question 1

How to disable method conflict warnings in Hashie Mash?

Accepted Answer

Use disable_warnings in a Mash subclass or Hashie::Mash.quiet for anonymous subclasses. For example, class MyMash < Hashie::Mash; disable_warnings; end silences all conflicts.

Question 2

Hashie vs ActiveSupport Hash extensions for Rails projects?

Accepted Answer

Hashie offers more specialized features like Dash for structured data and deep operations, while ActiveSupport is better integrated with Rails but less modular. Choose Hashie for complex hash manipulation outside Rails core.

Question 3

Can Hashie handle boolean coercion in hashes?

Accepted Answer

Yes, but not natively—you must use a custom coercion proc since Ruby lacks a built-in boolean type. The README shows an example with a lambda to coerce strings or numbers to booleans.

Question 4

What's the difference between Mash and Dash in Hashie?

Accepted Answer

Mash is a flexible pseudo-object with method access and indifferent keys, while Dash enforces defined properties with requirements and defaults. Use Mash for dynamic data, Dash for structured models.

Question 5

How to avoid memory leaks with Hashie on older Ruby?

Accepted Answer

Avoid SymbolizeKeys extension on Rubies pre-2.0, as symbols aren't garbage-collected. Stick to string keys or use KeepOriginalKeys to prevent unintended symbol generation from user input.

Question 6

Does Hashie work with Rails strong parameters?

Accepted Answer

Not directly—you need the hashie-forbidden_attributes gem for compatibility. The README notes this for Dash and Mash when used in Rails 4+ contexts.

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