Ruby on Rails Research & Evidence-Based Practice 5

Question 1

Which metric from Rails' production logs provides the most direct evidence of a memory leak in a long-running process?

Accepted Answer

Monotonically growing RSS memory reported by `ps` or `top`

Answer

RSS (Resident Set Size) that grows without bound across requests over time is the canonical evidence of a memory leak.

Question 2

In test-driven Rails development, what constitutes 'evidence' that a new feature is complete?

Accepted Answer

All acceptance tests written from requirements pass and no existing tests regress

Answer

Passing acceptance tests derived directly from requirements, with no regressions, provide objective evidence of feature completeness.

Question 3

A Rails team wants empirical evidence about which pages users exit most. Which integration provides this behavioral data?

Accepted Answer

Google Analytics or similar with exit page tracking

Answer

Analytics platforms like Google Analytics track exit pages by instrumenting real user sessions, providing behavioral evidence for UX decisions.

Question 4

Which approach provides the strongest evidence when deciding whether to extract a Rails service object from a fat model?

Accepted Answer

Measuring test execution time and cyclomatic complexity before and after

Answer

Measuring cyclomatic complexity and test suite speed before and after extraction provides objective evidence that the refactor improved maintainability.

Question 5

What is the purpose of a Rails `config/initializers/inflections.rb` research spike, and how should findings be documented?

Accepted Answer

Document unexpected pluralization edge cases as failing tests before fixing them

Answer

Documenting edge cases as failing tests before fixing them captures the discovered behavior as verifiable evidence for future developers.

Ruby on Rails Practice Test

Ruby on Rails Practice Test

Ruby on Rails Research & Evidence-Based Practice 5