Add new Rails/ActiveRecordCalculation cop
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fatkodima
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Earlopain
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Sep 22, 2024
| module RuboCop | ||
| module Cop | ||
| module Rails | ||
| # Enforces the use of ActiveRecord calculation methods instead of `pluck` |
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Let's add the rationale here: it avoids loading potentially many values into memory by doing the calculations through the equivalent database function.
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| Rails/ActiveRecordCalculation: | ||
| Description: 'Use ActiveRecord calculation methods instead of `pluck` followed by Enumerable methods.' | ||
| Enabled: pending | ||
| VersionAdded: '<<next>>' |
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This would need to be marked unsafe because Ruby's sum/max aren't always compatible with the DB's:
User.pluck(:name).sum # "AliceBobCathy"
User.sum(:name) # PG::UndefinedFunction: ERROR: function sum(character varying) does not exist| # User.pluck(:email).max { |email| email.length } | ||
| # User.pluck(:email).max(2) | ||
| # User.pluck(:id, :company_id).max | ||
| # User.pluck(:age).count |
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This is kinda a weird counterexample, because User.count(:age) would actually be more efficient and falls in line with this cop's premise. 🤔
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Closes #1205.
In my app I found 11 offences of this cop.