Rails-Pluck.md

Pattern: Use of map instead of pluck

Issue: -

Description

This rule enforces the use of pluck over map.

pluck can be used instead of map to extract a single key from each element in an enumerable. When called on an Active Record relation, it results in a more efficient query that only selects the necessary key.

Examples

# bad
Post.published.map { |post| post[:title] }
[{ a: :b, c: :d }].collect { |el| el[:a] }

# good
Post.published.pluck(:title)
[{ a: :b, c: :d }].pluck(:a)

Further Reading

• RuboCop - Rails/Pluck