N+1 detector gem Prosopite (replacing gem Bullet) by compwron · Pull Request #6744 · rubyforgood/casa

compwron · 2026-03-03T03:20:28Z

Copilot

Pull request overview

Replaces Bullet with Prosopite for N+1 query detection, adding configuration for development/test (and optional production toggles) plus RSpec integration and an ignore mechanism to support gradual rollout.

Changes:

Swap bullet for prosopite in dependencies and environment config.
Add a Rails initializer to configure Prosopite (middleware + core settings).
Add RSpec support to scan examples, pause during FactoryBot creation, and support an ignore list / TODO tracking.

Reviewed changes

Copilot reviewed 8 out of 9 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
spec/support/prosopite.rb	Adds RSpec + FactoryBot integration and ignore-list logic for Prosopite scanning
spec/.prosopite_ignore	Introduces ignore list file for incremental rollout
config/initializers/prosopite.rb	Configures Prosopite middleware/settings after Rails initialization
config/environments/test.rb	Enables Prosopite settings for test environment (replacing Bullet config)
config/environments/development.rb	Enables Prosopite settings for development environment (replacing Bullet config)
config/environments/production.rb	Adds env-driven Prosopite toggles for production
PROSOPITE_TODO.md	Captures detected N+1 locations for follow-up work
Gemfile.lock	Removes Bullet and adds Prosopite gem
Gemfile	Replaces Bullet with Prosopite dependency (dev/test group)

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Copilot · 2026-03-20T18:32:18Z

config/initializers/prosopite.rb

+# Only enable Rack middleware if Prosopite is configured on
+if Rails.configuration.respond_to?(:prosopite_enabled) && Rails.configuration.prosopite_enabled
+  require "prosopite/middleware/rack"
+  Rails.configuration.middleware.use(Prosopite::Middleware::Rack)
+end
+
+Rails.application.config.after_initialize do
+  # Core settings
+  Prosopite.enabled = Rails.configuration.respond_to?(:prosopite_enabled) &&
+    Rails.configuration.prosopite_enabled
+
+  # Minimum repeated queries to trigger detection (default: 2)
+  Prosopite.min_n_queries = Rails.configuration.respond_to?(:prosopite_min_n_queries) ?
+                            Rails.configuration.prosopite_min_n_queries : 2
+
+  # Logging options
+  Prosopite.rails_logger = true                    # Log to Rails.logger
+  Prosopite.prosopite_logger = Rails.env.development?  # Log to log/prosopite.log
+end


Prosopite is referenced unconditionally inside after_initialize, but the gem is only in the :development, :test group. In production (and any env without the gem), this initializer will raise NameError during boot. Wrap the entire initializer (including the after_initialize block) in return unless defined?(Prosopite) / if defined?(Prosopite) or move the gem to a group that is bundled in the environments where this initializer runs (and handle the case where prosopite_enabled is true but the gem isn't available).

spec/support/prosopite.rb

Copilot · 2026-03-20T18:32:18Z

spec/support/prosopite.rb

+def use_prosopite?(example)
+  # Explicit metadata takes precedence
+  return false if example.metadata[:disable_prosopite]
+  return true if example.metadata[:enable_prosopite]
+
+  # Check against ignore list
+  PROSOPITE_IGNORE.none? do |path|
+    File.fnmatch?("./#{path}/*", example.metadata[:rerun_file_path].to_s)
+  end


use_prosopite? is defined at the top level, which adds a method to Object and can leak into other specs/helpers. Define it in a module (e.g., Support::Prosopite) and call it from the RSpec hook, or define it as a local lambda inside the RSpec.configure block to avoid global namespace pollution.

Copilot · 2026-03-20T18:32:19Z

spec/support/prosopite.rb

+
+# Optional: Load ignore list from file for gradual rollout
+PROSOPITE_IGNORE = if File.exist?("spec/.prosopite_ignore")
+  File.read("spec/.prosopite_ignore").lines.map(&:chomp).reject(&:empty?)


The ignore list loader keeps comment lines (starting with #) and doesn’t strip surrounding whitespace. That makes it easy to accidentally add a path like spec/features that never matches, and the file header comments will always be processed. Consider filtering out comment lines and trimming whitespace before matching.

Suggested change

File.read("spec/.prosopite_ignore").lines.map(&:chomp).reject(&:empty?)

File.read("spec/.prosopite_ignore").lines

.map { |line| line.strip }

.reject { |line| line.empty? || line.start_with?("#") }

Gemfile

- Set Prosopite.raise = true so N+1s fail specs instead of silently logging - Populate .prosopite_ignore with known-issue directories for gradual rollout - Scope initializer to development only; spec/support/prosopite.rb owns test config - Remove redundant prosopite settings from test.rb and production.rb - Replace fragile FactoryBot::Strategy::Create monkey-patch with SyntaxRunner hook - Filter comment lines in .prosopite_ignore parser Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Copilot

Pull request overview

Copilot reviewed 7 out of 8 changed files in this pull request and generated 4 comments.

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Copilot · 2026-03-23T15:12:51Z

Gemfile

+group :development, :test, :production do
  gem "brakeman" # Security inspection
-  gem "bullet" # Detect and fix N+1 queries
+  gem "prosopite" # N+1 query detection via SQL pattern analysis


Changing this group to include :production will also bundle/require a large set of dev/test-only gems (e.g., rspec-rails, factory_bot_rails, linters) in production, increasing boot time/memory and potentially introducing production-only dependency conflicts. Keep the group as :development, :test and, if Prosopite truly needs to be available in production, place only prosopite in its own appropriate group (or mark it require: false) instead of pulling the entire dev/test toolchain into production.

Copilot · 2026-03-23T15:12:51Z

spec/support/prosopite.rb

+  PROSOPITE_IGNORE.none? do |path|
+    File.fnmatch?("./#{path}/*", example.metadata[:rerun_file_path].to_s)


The ignore matching here appears to use a nonstandard RSpec metadata key (:rerun_file_path), which is likely to be nil for most examples. That would prevent the ignore list from ever matching and cause Prosopite to run/raise in specs that are supposed to be ignored. Use the actual spec file path metadata key (e.g., :file_path/:absolute_file_path) when comparing against .prosopite_ignore.

Suggested change

PROSOPITE_IGNORE.none? do |path|

File.fnmatch?("./#{path}/*", example.metadata[:rerun_file_path].to_s)

spec_path = example.metadata[:absolute_file_path] ||

example.metadata[:file_path] ||

example.metadata[:rerun_file_path]

PROSOPITE_IGNORE.none? do |path|

File.fnmatch?("./#{path}/*", spec_path.to_s)

spec/support/prosopite.rb

Copilot

Pull request overview

Copilot reviewed 7 out of 8 changed files in this pull request and generated 3 comments.

Comments suppressed due to low confidence (1)

Gemfile:76

group :development, :test, :production pulls a large set of dev/test-only gems (brakeman, byebug, rspec-rails, rubocop, etc.) into production. This can bloat the production image and may introduce operational/security risk. Consider reverting this group back to :development, :test and, if Prosopite must be available in production, add only prosopite to a separate :production (or :development-only) group as appropriate.

group :development, :test, :production do
  gem "brakeman" # Security inspection
  gem "prosopite" # N+1 query detection via SQL pattern analysis
  gem "byebug", platforms: %i[mri mingw x64_mingw] # Debugger console
  gem "dotenv-rails" # Environment variable management
  gem "erb_lint", require: false # ERB linter
  gem "factory_bot_rails" # Test data factories
  gem "faker" # Creates realistic seed data, valuable for staging and demos
  gem "parallel_tests" # Run tests in parallel
  gem "pry" # Enhanced Ruby console
  gem "pry-byebug" # Pry debugger integration
  gem "rspec_junit_formatter" # JUnit XML formatter for RSpec
  gem "rspec-rails" # RSpec testing framework

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Copilot · 2026-03-26T03:26:30Z

spec/support/prosopite.rb

+  # Check against ignore list
+  PROSOPITE_IGNORE.none? do |path|
+    File.fnmatch?("./#{path}/*", example.metadata[:rerun_file_path].to_s)
+  end


Ignore matching is currently very brittle: it relies on example.metadata[:rerun_file_path], which may be unset for many runs, and it matches against a pattern prefixed with ./ (while RSpec file paths are typically spec/... or absolute). If :rerun_file_path is nil, the ignore list will never match and Prosopite will scan everything. Consider using example.metadata[:file_path] (or example.location) and normalizing paths before matching (e.g., via File.expand_path).

Copilot · 2026-03-26T03:26:30Z

PROSOPITE_TODO.md

+users.each { |u| u.orders.count }
+
+# After (eager loading)
+users.includes(:orders).each { |u| u.orders.count }


The "After (eager loading)" example still calls u.orders.count, which issues a separate COUNT(*) query per user even when the association is preloaded. To demonstrate fixing an N+1, this should use u.orders.size/length (or a counter cache / precomputed aggregate) instead of count.

Suggested change

users.includes(:orders).each { |u| u.orders.count }

users.includes(:orders).each { |u| u.orders.size }

Copilot · 2026-03-26T03:26:30Z

spec/support/prosopite.rb

+        alias_method :original_create, :create
+
+        def create(*args, **kwargs, &block)
+          if defined?(Prosopite) && Prosopite.enabled?
+            Prosopite.pause { original_create(*args, **kwargs, &block) }
+          else
+            original_create(*args, **kwargs, &block)


This FactoryBot monkey-patch can break under Spring: each spec run re-enters before(:suite) and re-aliases original_create to the already-wrapped create, which can lead to recursion/stack overflow. Guard the aliasing so it only happens once per process (e.g., check method_defined?) or prefer a Module#prepend wrapper that is idempotent.

Suggested change

alias_method :original_create, :create

def create(*args, **kwargs, &block)

if defined?(Prosopite) && Prosopite.enabled?

Prosopite.pause { original_create(*args, **kwargs, &block) }

else

original_create(*args, **kwargs, &block)

unless method_defined?(:original_create)

alias_method :original_create, :create

def create(*args, **kwargs, &block)

if defined?(Prosopite) && Prosopite.enabled?

Prosopite.pause { original_create(*args, **kwargs, &block) }

else

original_create(*args, **kwargs, &block)

end

github-actions bot added dependencies Pull requests that update a dependency file ruby Pull requests that update Ruby code labels Mar 3, 2026

compwron force-pushed the prosopite-2 branch from 8d1b97e to eeb3a2e Compare March 20, 2026 18:21

compwron marked this pull request as ready for review March 20, 2026 18:29

compwron requested review from FireLemons and elasticspoon as code owners March 20, 2026 18:29

compwron requested a review from Copilot March 20, 2026 18:29

compwron enabled auto-merge (rebase) March 20, 2026 18:29

Copilot started reviewing on behalf of compwron March 20, 2026 18:29 View session

Copilot AI reviewed Mar 20, 2026

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compwron requested a review from Copilot March 23, 2026 15:08

compwron and others added 7 commits March 23, 2026 08:08

add prosopite

1146c66

remove bullet now that we have prosopite

6bc37a9

prosopite todo list

7a8d67d

lintfix

d0f5517

Update Gemfile

85fd417

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Update spec/support/prosopite.rb

f9cd33a

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Copilot started reviewing on behalf of compwron March 23, 2026 15:08 View session

compwron force-pushed the prosopite-2 branch from 7291c11 to f9cd33a Compare March 23, 2026 15:10

Copilot AI reviewed Mar 23, 2026

View reviewed changes

add ignore files for now

5769eb6

compwron force-pushed the prosopite-2 branch from 90a1f63 to 5769eb6 Compare March 23, 2026 23:31

compwron requested a review from Copilot March 26, 2026 03:22

Copilot started reviewing on behalf of compwron March 26, 2026 03:23 View session

compwron changed the title ~~WIP N+1 detector gem Prosopite (replacing gem Bullet)~~ N+1 detector gem Prosopite (replacing gem Bullet) Mar 26, 2026

compwron disabled auto-merge March 26, 2026 03:23

compwron merged commit 8399953 into main Mar 26, 2026
13 checks passed

compwron deleted the prosopite-2 branch March 26, 2026 03:24

Copilot AI reviewed Mar 26, 2026

View reviewed changes

		PROSOPITE_IGNORE.none? do \|path\|
		File.fnmatch?("./#{path}/*", example.metadata[:rerun_file_path].to_s)

	users.includes(:orders).each { \|u\| u.orders.count }
	users.includes(:orders).each { \|u\| u.orders.size }

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compwron commented Mar 3, 2026 •

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