[bot] Fix Rails/Delegate

[6]

Automated fix fix for Rails/Delegate corpus conformance.

Refs #162

Details

Cop	Rails/Delegate
Backend	codex / hard
Model	gpt-5.4 (xhigh)
Mode	fix
Turns	1
Run	#98

Result

Updated [src/cop/rails/delegate.rs](/home/runner/work/nitrocop/nitrocop/src/cop/rails/delegate.rs) with a `///` investigation note and fixed [tests/fixtures/cops/rails/delegate/offense.rb](/home/runner/work/nitrocop/nitrocop/tests/fixtures/cops/rails/delegate/offense.rb) so the representative FN snippets are complete real cases instead of placeholders.

`cargo test --lib -- cop::rails::delegate` passes. The required corpus gate still fails: `python3 scripts/check_cop.py Rails/Delegate --rerun --clone --sample 15` reports `+82 FN` and `+2 FP` on the sample. The investigation shows those representative FN patterns are already detected when the files are passed explicitly, but they disappear in repo-root corpus runs, so the remaining gap is outside this cop and looks like repo-root file selection / config handling rather than `Rails/Delegate` matcher logic.

Committed on the current branch as `7191220b` with message `Document Rails/Delegate corpus investigation`.

Changes

  2 files changed

Agent conversation excerpt

Reading the CI-specific instructions and the existing Rails/Delegate implementation first, then I’ll reproduce the targeted delegate cases to identify the detection gap before editing fixtures or Rust code.

Reading the CI-specific instructions and the existing Rails/Delegate implementation first, then I’ll reproduce the targeted delegate cases to identify the detection gap before editing fixtures or Rust code.

exec_command: sed -n '1,220p' docs/agent-ci.md

exec_command: sed -n '1,260p' src/cop/rails/delegate.rs

exec_command: sed -n '1,260p' vendor/rubocop-rails/lib/rubocop/cop/rails/delegate.rb

exec_command: sed -n '1,260p' vendor/rubocop-rails/spec/rubocop/cop/rails/delegate_spec.rb

exec_command: sed -n '1,260p' tests/fixtures/cops/rails/delegate/offense.rb

exec_command: sed -n '1,260p' tests/fixtures/cops/rails/delegate/no_offense.rb

I’ve loaded the CI scope rules and the Rails/Delegate sources. Next I’m tracing the current matcher against these new FN patterns, because the fixture already contains them and that points to a body-shape gap rather than missing coverage.

I’ve loaded the CI scope rules and the Rails/Delegate sources. Next I’m tracing the current matcher against these new FN patterns, because the fixture already contains them and that points to a body-shape gap rather than missing coverage.

exec_command: sed -n '261,520p' src/cop/rails/delegate.rs

exec_command: sed -n '261,520p' tests/fixtures/cops/rails/delegate/no_offense.rb

exec_command: python3 scripts/investigate_cop.py Rails/Delegate --context

exec_command: sed -n '521,760p' src/cop/rails/delegate.rs

exec_command: sed -n '761,980p' src/cop/rails/delegate.rs

exec_command: nl -ba tests/fixtures/cops/rails/delegate/offense.rb | tail -n 40

The fixture tail is currently incomplete: the new FN snippets were inserted without bodies, so I’m checking the failing test output now to separate fixture breakage from the real matcher bug.

The fixture tail is currently incomplete: the new FN snippets were inserted without bodies, so I’m checking the failing test output now to separate fixture breakage from the real matcher bug.

exec_command: cargo test --lib -- cop::rails::delegate

write_stdin: ``

write_stdin: ``

The current failure is still fixture-driven: only def pop = frames.pop has enough source to exercise the cop, and the other seven new expectations are missing their method bodies. I’m going to patch the fixture with the full corpus snippets first, rerun the targeted test, and then only touch the Rust matcher if the real FN remains.

The current failure is still fixture-driven: only def pop = frames.pop has enough source to exercise the cop, and the other seven new expectations are missing their method bodies. I’m going to patch the fixture with the full corpus snippets first, rerun the targeted test, and then only touch the Rust matcher if the real FN remains.

update_plan

write_stdin: ``

The corpus examples are concentrated in vendored rdoc code, so I’m checking whether the file-level context trips one of our line-scanning visibility/module-function guards. If the simple fixtures pass after being completed, that’s the likely failure mode.

The corpus examples are concentrated in vendored rdoc code, so I’m checking whether the file-level context trips one of our line-scanning visibility/module-function guards. If the simple fixtures pass after being completed, that’s the likely failure mode.

exec_command: rg -n "module_function|private|protected" vendor/corpus/cjstewart88__Tubalr__f6956c8/heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb vendor/corpus/cjstewart88__Tubalr__f6956c8/heroku/ruby/1.9.1/gem

exec_command: sed -n '560,660p' vendor/corpus/cjstewart88__Tubalr__f6956c8/heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb

exec_command: sed -n '1,120p' vendor/corpus/cjstewart88__Tubalr__f6956c8/heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup/list.rb

exec_command: sed -n '1,120p' vendor/corpus/cjstewart88__Tubalr__f6956c8/heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup/list_item.rb

I’m patching the offense fixture now with the actual method bodies from the corpus examples so the test exercises the real patterns instead of placeholders.

I’m patching the offense fixture now with the actual method bodies from the corpus examples so the test exercises the real patterns instead of placeholders.

apply_patch

update_plan

exec_command: cargo test --lib -- cop::rails::delegate

write_stdin: ``

write_stdin: ``

The completed corpus snippets all pass with the current matcher, so this is no longer a simple detection bug. I’m validating against the real corpus next to see whether the remaining FN/FP come from file-context handling that only shows up outside the fixture.

The completed corpus snippets all pass with the current matcher, so this is no longer a simple detection bug. I’m validating against the real corpus next to see whether the remaining FN/FP come from file-context handling that only shows up outside the fixture.

exec_command: rg --files vendor | rg 'rdoc-3\.8/lib/rdoc/markup\.rb|rdoc-3\.8/lib/rdoc/markup/list\.rb|rdoc-3\.8/lib/rdoc/markup/list_item\.rb|account_env_var\.rb|scalar\.rb|rack/utils\.rb'

exec_command: python3 scripts/check_cop.py Rails/Delegate --rerun --clone --sample 15

write_stdin: ``

write_stdin: ``

write_stdin: ``

The corpus rerun is in progress now. The key question is whether the real sampled repos still miss these delegations with full-file context; if they do, I’ll have the concrete file set needed to trace the scope logic instead of guessing from isolated snippets.

The corpus rerun is in progress now. The key question is whether the real sampled repos still miss these delegations with full-file context; if they do, I’ll have the concrete file set needed to trace the scope logic instead of guessing from isolated snippets.

write_stdin: ``

write_stdin: ``

The sample corpus rerun confirms the real issue is still there: the sampled repos reproduce +82 FN and +2 FP, so this isn’t just a fixture gap. I’ve got the cloned repos locally now, and I’m moving to one of the concrete missed files to see which scope check is suppressing the offense in full context.

The sample corpus rerun confirms the real issue is still there: the sampled repos reproduce +82 FN and +2 FP, so this isn’t just a fixture gap. I’ve got the cloned repos locally now, and I’m moving to one of the concrete missed files to see which scope check is suppressing the offense in full context.

exec_command: ls -1 /tmp/nitrocop_cop_check_e7mch_5m | sed -n '1,40p'

exec_command: sed -n '560,660p' /tmp/nitrocop_cop_check_e7mch_5m/cjstewart88__Tubalr__f6956c8/heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb

exec_command: sed -n '1,120p' /tmp/nitrocop_cop_check_e7mch_5m/cjstewart88__Tubalr__f6956c8/heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup/list.rb

exec_command: sed -n '1,120p' /tmp/nitrocop_cop_check_e7mch_5m/cjstewart88__Tubalr__f6956c8/heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup/list_item.rb

exec_command: find /tmp/nitrocop_cop_check_e7mch_5m/repos -maxdepth 2 -mindepth 1 -type d | sed -n '1,40p'

exec_command: find /tmp/nitrocop_cop_check_e7mch_5m/repos -path '*rdoc-3.8/lib/rdoc/markup.rb' -o -path '*rdoc-3.8/lib/rdoc/markup/list.rb' -o -path '*rdoc-3.8/lib/rdoc/markup/list_item.rb' | sed -n '1,40p'

exec_command: sed -n '560,660p' /tmp/nitrocop_cop_check_e7mch_5m/repos/cjstewart88__Tubalr__f6956c8/heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb

exec_command: sed -n '1,120p' /tmp/nitrocop_cop_check_e7mch_5m/repos/cjstewart88__Tubalr__f6956c8/heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup/list.rb

exec_command: sed -n '1,120p' /tmp/nitrocop_cop_check_e7mch_5m/repos/cjstewart88__Tubalr__f6956c8/heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup/list_item.rb

Task prompt (6309 tokens)

Fix Rails/Delegate — 3 FP, 78 FN

Instructions

You are fixing ONE cop in nitrocop, a Rust Ruby linter that uses Prism for parsing.

Current state: 23,053 matches, 3 false positives, 78 false negatives.
Focus on: FN (RuboCop flags code nitrocop misses).

⚠ 23,053 existing matches must not regress. Validate with check_cop.py before committing.

Workflow

1. Read the Pre-diagnostic Results and Corpus FP/FN Examples sections below first
2. Verify with RuboCop first (for FP fixes): before writing any code, confirm RuboCop's
   behavior on BOTH the specific FP case AND the general pattern:

   echo '<specific FP case>' > /tmp/test.rb && rubocop --only Rails/Delegate /tmp/test.rb
   echo '<general pattern>' > /tmp/test.rb && rubocop --only Rails/Delegate /tmp/test.rb

   If RuboCop flags the general pattern, your fix must be narrow enough to not suppress it.
3. Add a test case FIRST:
   • FN fix: add the missed pattern to tests/fixtures/cops/rails/delegate/offense.rb with ^ annotation
   • FP fix: add the false-positive pattern to tests/fixtures/cops/rails/delegate/no_offense.rb
4. Verify test fails: cargo test --lib -- cop::rails::delegate
5. Fix src/cop/rails/delegate.rs
6. Verify test passes: cargo test --lib -- cop::rails::delegate
7. Validate against corpus (REQUIRED before committing):

   python3 scripts/check_cop.py Rails/Delegate --rerun --clone --sample 15

   If this reports FP or FN regression, your fix is too broad — narrow it down.
8. Add a /// doc comment on the cop struct documenting what you found and fixed
9. Commit only your cop's files

Fixture Format

Mark offenses with ^ markers on the line AFTER the offending source line.
The ^ characters must align with the offending columns. The message format is Rails/Delegate: <message text>.
See the Current Fixture sections below for real examples from this cop.

Mixed issues: some code bugs, some config issues

Pre-diagnostic shows SOME patterns are correctly detected in isolation (config issues)
and SOME are genuinely missed (code bugs). See the per-example diagnosis below.

• For examples marked CODE BUG: follow the standard TDD workflow
• For examples marked CONFIG/CONTEXT: investigate config resolution, not detection logic

If your test passes immediately

If you add a test case and it passes without code changes, the corpus mismatch is
caused by config/context differences, not a detection bug.
Do NOT loop trying to make the test fail. Instead:

1. Investigate config resolution (Include/Exclude, cop enablement, disable comments)
2. The fix is likely in src/config/ or the cop's config handling, not detection logic
3. If you cannot determine the root cause within 5 minutes, document your findings as
   a /// comment on the cop struct and commit

CRITICAL: Avoid regressions in the opposite direction

When fixing FPs, your change MUST NOT suppress legitimate detections. When fixing FNs,
your change MUST NOT flag code that RuboCop accepts. A fix that eliminates a few issues
in one direction but introduces hundreds in the other is a catastrophic regression.

Before exempting a category of patterns, verify with RuboCop that the general case
is still an offense:

rubocop --only Rails/Delegate /tmp/test.rb

If RuboCop flags the general pattern but not your specific case, the difference is in
a narrow context (e.g., enclosing structure, receiver type, argument count) — your fix
must target that specific context, not the broad category.

Rule of thumb: if your fix adds an early return or continue that skips a whole
node type, operator class, or naming pattern, it's probably too broad. Prefer adding a
condition that matches the SPECIFIC differentiating context.

Rules

• Only modify src/cop/rails/delegate.rs and tests/fixtures/cops/rails/delegate/
• Run cargo test --lib -- cop::rails::delegate to verify your fix (do NOT run the full test suite)
• Run python3 scripts/check_cop.py Rails/Delegate --rerun --clone --sample 15 before committing to catch regressions
• Do NOT touch unrelated files
• Do NOT use git stash

Prism Notes

• const splits into ConstantReadNode (simple Foo) and ConstantPathNode (qualified Foo::Bar). If you handle one, check if you need the other.

Current Fixture: offense.rb

tests/fixtures/cops/rails/delegate/offense.rb

def name
^^^ Rails/Delegate: Use `delegate` to define delegations.
  client.name
end

def email
^^^ Rails/Delegate: Use `delegate` to define delegations.
  account.email
end

def title
^^^ Rails/Delegate: Use `delegate` to define delegations.
  post.title
end

def site_title
^^^ Rails/Delegate: Use `delegate` to define delegations.
  Setting.site_title
end

def [](key)
^^^ Rails/Delegate: Use `delegate` to define delegations.
  @attrs[key]
end

def []=(key, value)
^^^ Rails/Delegate: Use `delegate` to define delegations.
  @attrs[key] = value
end

def fetch(arg)
^^^ Rails/Delegate: Use `delegate` to define delegations.
  client.fetch(arg)
end

def label
^^^ Rails/Delegate: Use `delegate` to define delegations.
  self.class.label
end

# Prefixed delegation: def receiver_method; receiver.method; end
def bar_foo
^^^ Rails/Delegate: Use `delegate` to define delegations.
  bar.foo
end

def client_name
^^^ Rails/Delegate: Use `delegate` to define delegations.
  client.name
end

def config_value(key)
^^^ Rails/Delegate: Use `delegate` to define delegations.
  config.value(key)
end

# Endless method delegations (def foo = bar.foo)
def first = value.first
^^^ Rails/Delegate: Use `delegate` to define delegations.

def last = value.last
^^^ Rails/Delegate: Use `delegate` to define delegations.

def empty? = value.empty?
^^^ Rails/Delegate: Use `delegate` to define delegations.

def size = value.size
^^^ Rails/Delegate: Use `delegate` to define delegations.

def stop = @listener.stop
^^^ Rails/Delegate: Use `delegate` to define delegations.

def root = Engine.root
^^^ Rails/Delegate: Use `delegate` to define delegations.

# Prefixed delegation via self.class receiver: def class_name; self.class.name; end
def class_name
^^^ Rails/Delegate: Use `delegate` to define delegations.
  self.class.name
end

# Direct delegation via self.class (method name matches exactly)
def associations
^^^ Rails/Delegate: Use `delegate` to define delegations.
  self.class.associations
end

def mailer_name
^^^ Rails/Delegate: Use `delegate` to define delegations.
  self.class.mailer_name
end

# Single-line self.class delegation
def keys; self.class.keys; end
^^^ Rails/Delegate: Use `delegate` to define delegations.

# private :method_name with MULTIPLE symbols — RuboCop's pattern only matches single-symbol
# private calls, so private :[]=, :set_element doesn't make []= private for this cop
def []=(i, v)
^^^ Rails/Delegate: Use `delegate` to define delegations.
  @elements[i]= v
end
private :[]=, :set_element, :set_component

# MF declaration in a nested scope should NOT suppress offense at outer level
def check_for_pending_migrations
^^^ Rails/Delegate: Use `delegate` to define delegations.
  Tasks.check_for_pending_migrations
end

# Single-line def methods (inline def...end on one line)
def owner; parser.owner end
^^^ Rails/Delegate: Use `delegate` to define delegations.

def namespace; parser.namespace end
^^^ Rails/Delegate: Use `delegate` to define delegations.

def adapters; Adapter.adapters end
^^^ Rails/Delegate: Use `delegate` to define delegations.

# Methods followed by identifiers containing "module_function" as substring
# should NOT be suppressed — only actual `module_function` calls count
class Handler
  def scope; parser.scope end
  ^^^ Rails/Delegate: Use `delegate` to define delegations.

  def register_module_function(object)
    object.module_function
  end
end

# self.class delegation inside a class/module (nested context)
module Document
  def tag
  ^^^ Rails/Delegate: Use `delegate` to define delegations.
    self.class.tag
  end

  def aliases
  ^^^ Rails/Delegate: Use `delegate` to define delegations.
    self.class.aliases
  end
end

# Private inside a sibling module at the same indent level should NOT suppress
# instance methods outside that module. Pattern from mongomapper: module ClassMethods
# declares `private` at the same indent as the enclosing module's instance methods.
module Plugins
  module Associations
    module ClassMethods
    private
      def create_association(assoc)
        assoc.setup(self)
      end
    end

    def associations
    ^^^ Rails/Delegate: Use `delegate` to define delegations.
      self.class.associations
    end

    def embedded_associations
    ^^^ Rails/Delegate: Use `delegate` to define delegations.
      self.class.embedded_associations
    end
  end
end

# Delegation inside a conditional block after `private` — RuboCop's AST-based sibling
# check doesn't see `private` as affecting defs inside if/else bodies, because the def
# is a child of the if-node, not the class body. Pattern from asciidoctor/timings.rb.
class Timer
  private

  if CONST_DEFINED
    def now
    ^^^ Rails/Delegate: Use `delegate` to define delegations.
      FastClock.now
    end
  else
    def now
    ^^^ Rails/Delegate: Use `delegate` to define delegations.
      ::Time.now
    end
  end
end

Current Fixture: no_offense.rb

tests/fixtures/cops/rails/delegate/no_offense.rb

def name
  client.name.upcase
end

def name(arg)
  client.name
end

def name
  compute_something
end

delegate :name, to: :client

# Class method receivers can't use delegate
def no_replies_scope
  Status.without_replies
end

def find_user
  User.find_by_email(email)
end

# Method name doesn't match delegated method — not a simple delegation
def valid?
  json.present?
end

def cdn_host
  config.asset_host
end

# Safe navigation is ignored
def author_url
  structured_data&.author_url
end

# Argument forwarding with transformation (not simple delegation)
def fetch(key)
  client.fetch(key.to_s)
end

# Argument count mismatch
def [](key, default)
  @attrs[key]
end

# Private methods are ignored — including methods after other method `end`s
# in the same private section
private

def custom_filter
  object.custom_filter
end

def logger
  Rails.logger
end

def discoverable
  Account.discoverable
end

# module_function makes methods private — delegate doesn't apply
module Helpers
  module_function

  def name
    self.name
  end
end

# module_function on a separate line before the method
module Utils
  module_function

  def label
    config.label
  end
end

# inline module_function before def
module Formatters
  module_function def format
    self.format
  end
end

# private :method_name after def — makes the method private (single symbol only)
# RuboCop's pattern (send nil? VISIBILITY_SCOPES (sym %method_name)) only matches
# when there's exactly one symbol argument
def status
  record.status
end
private :status

# EnforceForPrefixed: false patterns with non-CallNode receivers
# (these are skipped in our prefix check but tested elsewhere)

# Receiver is a method call with arguments — not a simple delegation target
def fox
  bar(42).fox
end

# Method args don't match (param is used as receiver, not forwarded)
def fox(bar)
  bar.fox
end

# module_function :name AFTER the def — RuboCop skips these
module Adapter
  def adapters
    Adapter.adapters
  end; module_function :adapters

  def register(name, condition)
    Adapter.register(name, condition)
  end; module_function :register
end

# module_function :name on a subsequent line in the same module scope
module SecurityUtils
  def secure_compare(a, b)
    OpenSSL.fixed_length_secure_compare(a, b)
  end

  module_function :secure_compare
end

# module_function in ancestor module — class nested inside module
# RuboCop's module_function_declared? checks ALL ancestors, not just immediate scope
module Open4
  module_function :open4
  class SpawnError < StandardError
    def exitstatus
      @status.exitstatus
    end
  end
end

# Endless method with chained call — not a simple delegation
class Foo
  def formatted_name = value.name.upcase
end

# Endless method with argument mismatch — not a delegation
class Bar
  def lookup(key) = data.find
end

# Private with trailing space — `private ` (with trailing space) on its own line
class Bar
  private
  def size
    @range.size
  end
end

# module_function in outer ancestor module (after nested class) suppresses delegation.
# RuboCop's module_function_declared? checks ALL ancestors, including outer modules.
# Pattern from antiwork/gumroad: module_function in StripePaymentMethodHelper (outer)
# suppresses delegation defs in nested ExtensionMethods module.
module StripeHelper
  module ExtensionMethods
    def to_customer_id
      to_customer.id
    end
  end

  class StripeUtils
    def self.build_error(msg)
      {error: msg}
    end
  end

  module_function

  def build(token:)
    card = {token:}
    card.extend(ExtensionMethods)
    card
  end
end

# module_function in outer module after nested class << self suppresses delegation.
# Pattern from palkan/anyway_config: class Trace inside module Tracing, with
# module_function declared in Tracing after the class << self singleton block.
module Tracing
  class Trace
    def clear() = value.clear
  end

  class << self
    def capture
      yield
    end

    private

    def source_stack
      []
    end
  end

  module_function

  def trace!(type, **opts)
    yield
  end
end

# private block with INDENTED def — private at lower indent than def
# Pattern from rails/rails: `private\n    def mkdir(dirs)`
class TestHelper
  private
    def mkdir(dirs)
      FileUtils.mkdir(dirs)
    end

    def entries
      @changelog.entries
    end
end

# `private def` inline modifier — private on same line as def
# Pattern from ruby/debug, codetriage/CodeTriage, pakyow/pakyow, ruby/rbs
class Config
  private def config
    self.class.config
  end

  private def parse_config_value(name, valstr)
    self.class.parse_config_value(name, valstr)
  end
end

# private def with question mark method — codetriage/CodeTriage pattern
class Issue
  private def pr_attached_with_issue?(pull_request_hash)
    self.class.pr_attached_with_issue?(pull_request_hash)
  end
end

# private def inside nested module — pakyow/pakyow pattern
module Support
  module Hookable
    module ClassMethods
      private def known_event?(event)
        self.class.known_event?(event)
      end

      private def hook_pipeline
        self.class.hook_pipeline
      end
    end
  end
end

# private def inside nested class — ruby/rbs pattern
module Collection
  module Sources
    class Stdlib
      private def lookup(name, version)
        REPO.lookup(name, version)
      end
    end
  end
end

# private block with indented def delegating to constant — antiwork/gumroad pattern
class ChargeProcessor
  private
    def paypal_api
      PaypalChargeProcessor.paypal_api
    end
end

Key Source Files

• Rust implementation: src/cop/rails/delegate.rs
• RuboCop Ruby source (ground truth): vendor/rubocop-rails/lib/rubocop/cop/rails/delegate.rb
• RuboCop test excerpts: vendor/rubocop-rails/spec/rubocop/cop/rails/delegate_spec.rb

Read these files before making changes.

Start Here

Use the existing corpus data to focus on the most concentrated regressions first.

Helpful local commands:

• python3 scripts/investigate_cop.py Rails/Delegate --repos-only
• python3 scripts/investigate_cop.py Rails/Delegate --context
• python3 scripts/verify_cop_locations.py Rails/Delegate

Top FP repos:

• cjstewart88__Tubalr__f6956c8 (1 FP) — example heroku/ruby/1.9.1/gems/rack-1.2.3/lib/rack/utils.rb:461
• travis-ci__travis-api__d1cbb6d (1 FP) — example lib/travis/api/v3/queries/account_env_var.rb:13
• travis-ci__travis-yaml__5b5fe81 (1 FP) — example lib/travis/yaml/nodes/scalar.rb:92

Top FN repos:

• cjstewart88__Tubalr__f6956c8 (30 FN) — example heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb:594
• liaoziyang__stackneveroverflow__8f4dce2 (21 FN) — example vendor/bundle/ruby/2.3.0/gems/rdoc-4.3.0/lib/rdoc/comment.rb:128
• pitluga__supply_drop__d64c50c (14 FN) — example examples/vendored-puppet/vendor/puppet-2.7.8/lib/puppet/util/autoload/file_cache.rb:14

Representative FP examples:

• cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rack-1.2.3/lib/rack/utils.rb:461 — Use delegate to define delegations.
• travis-ci__travis-api__d1cbb6d: lib/travis/api/v3/queries/account_env_var.rb:13 — Use delegate to define delegations.
• travis-ci__travis-yaml__5b5fe81: lib/travis/yaml/nodes/scalar.rb:92 — Use delegate to define delegations.

Representative FN examples:

• amuta__kumi__790c2e0: lib/kumi/core/analyzer/passes/lir/lower_pass.rb:48 — Use delegate to define delegations.
• cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb:594 — Use delegate to define delegations.
• cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb:601 — Use delegate to define delegations.

Pre-diagnostic Results

Diagnosis Summary

Each example was tested by running nitrocop on the extracted source in isolation
with --force-default-config to determine if the issue is a code bug or config issue.
Note: source context is truncated and may not parse perfectly. If a diagnosis
seems wrong (e.g., your test passes immediately for a 'CODE BUG'), treat it as
a config/context issue instead.

• FN: 10 code bug(s), 0 config/context issue(s)
• FP: 0 confirmed code bug(s), 1 context-dependent
• Omitted 5 pre-diagnostic FN example(s) with no source context because diagnosed FN examples were available
• Omitted 2 pre-diagnostic FP example(s) with no source context because diagnosed FP examples were available

FN #1: amuta__kumi__790c2e0: lib/kumi/core/analyzer/passes/lir/lower_pass.rb:48

NOT DETECTED — CODE BUG
The cop fails to detect this pattern. Fix the detection logic.

Message: Use delegate to define delegations.

Ready-made test snippet (add to offense.rb, adjust ^ count):

              def pop         = frames.pop
^ Rails/Delegate: Use `delegate` to define delegations.

Full source context:

              def initialize(**) = super(frames: [], memo: Hash.new { |h, k| h[k] = {} })
              def axes      = frames.map { _1[:axis] }
              def loop_ids  = frames.map { _1[:id] }
              def element_reg_for(axis)    = frames.reverse.find { _1[:axis] == axis }&.dig(:as_element)
              def index_reg_for(axis)      = frames.reverse.find { _1[:axis] == axis }&.dig(:as_index)
              def collection_reg_for(axis) = frames.reverse.find { _1[:axis] == axis }&.dig(:collection)
              def push(frame) = frames << frame
              def pop         = frames.pop
              def depth       = frames.length
              def memo_get(cat, key) = memo[cat][key]
              def memo_set(cat, key, val) = memo[cat][key] = val
              def invalidate_after_depth!(_d); end
            end

            # ---------- declarations ----------

FN #2: cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb:594

NOT DETECTED — CODE BUG
The cop fails to detect this pattern. Fix the detection logic.

Message: Use delegate to define delegations.

Ready-made test snippet (add to offense.rb, adjust ^ count):

  def add_word_pair(start, stop, name)
^ Rails/Delegate: Use `delegate` to define delegations.

Full source context:

  end

  ##
  # Add to the sequences used to add formatting to an individual word (such
  # as *bold*).  Matching entries will generate attributes that the output
  # formatters can recognize by their +name+.

  def add_word_pair(start, stop, name)
    @attribute_manager.add_word_pair(start, stop, name)
  end

  ##
  # Add to the sequences recognized as general markup.

  def add_html(tag, name)

FN #3: cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb:601

NOT DETECTED — CODE BUG
The cop fails to detect this pattern. Fix the detection logic.

Message: Use delegate to define delegations.

Ready-made test snippet (add to offense.rb, adjust ^ count):

  def add_html(tag, name)
^ Rails/Delegate: Use `delegate` to define delegations.

Full source context:

  def add_word_pair(start, stop, name)
    @attribute_manager.add_word_pair(start, stop, name)
  end

  ##
  # Add to the sequences recognized as general markup.

  def add_html(tag, name)
    @attribute_manager.add_html(tag, name)
  end

  ##
  # Add to other inline sequences.  For example, we could add WikiWords using
  # something like:
  #

FN #4: cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb:614

NOT DETECTED — CODE BUG
The cop fails to detect this pattern. Fix the detection logic.

Message: Use delegate to define delegations.

Ready-made test snippet (add to offense.rb, adjust ^ count):

  def add_special(pattern, name)
^ Rails/Delegate: Use `delegate` to define delegations.

Full source context:

  # something like:
  #
  #    parser.add_special(/\b([A-Z][a-z]+[A-Z]\w+)/, :WIKIWORD)
  #
  # Each wiki word will be presented to the output formatter via the
  # accept_special method.

  def add_special(pattern, name)
    @attribute_manager.add_special(pattern, name)
  end

  ##
  # We take +input+, parse it if necessary, then invoke the output +formatter+
  # using a Visitor to render the result.

FN #5: cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup/inline.rb:97

NOT DETECTED — CODE BUG
The cop fails to detect this pattern. Fix the detection logic.

Message: Use delegate to define delegations.

Ready-made test snippet (add to offense.rb, adjust ^ count):

    def [](n)
^ Rails/Delegate: Use `delegate` to define delegations.

Full source context:

        @attrs[i] |= bits
      end
    end

    ##
    # Accesses flags for character +n+

    def [](n)
      @attrs[n]
    end

  end

  ##
  # Hold details of a special sequence

FN #6: cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup/list.rb:28

NOT DETECTED — CODE BUG
The cop fails to detect this pattern. Fix the detection logic.

Message: Use delegate to define delegations.

Ready-made test snippet (add to offense.rb, adjust ^ count):

  def << item
^ Rails/Delegate: Use `delegate` to define delegations.

Full source context:

    @items = []
    @items.push(*items)
  end

  ##
  # Appends +item+ to the list

  def << item
    @items << item
  end

  def == other # :nodoc:
    self.class == other.class and
      @type == other.type and
      @items == other.items

FN #7: cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup/list_item.rb:54

NOT DETECTED — CODE BUG
The cop fails to detect this pattern. Fix the detection logic.

Message: Use delegate to define delegations.

Ready-made test snippet (add to offense.rb, adjust ^ count):

  def empty?
^ Rails/Delegate: Use `delegate` to define delegations.

Full source context:

    visitor.accept_list_item_end self
  end

  ##
  # Is the ListItem empty?

  def empty?
    @parts.empty?
  end

  ##
  # Length of parts in the ListItem

  def length

FN #8: cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup/list_item.rb:61

NOT DETECTED — CODE BUG
The cop fails to detect this pattern. Fix the detection logic.

Message: Use delegate to define delegations.

Ready-made test snippet (add to offense.rb, adjust ^ count):

  def length
^ Rails/Delegate: Use `delegate` to define delegations.

Full source context:

  def empty?
    @parts.empty?
  end

  ##
  # Length of parts in the ListItem

  def length
    @parts.length
  end

  def pretty_print q # :nodoc:
    q.group 2, '[item: ', ']' do
      if @label then
        q.text @label

Omitted 2 additional diagnosed FN example(s) for brevity.

FP #1: cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rack-1.2.3/lib/rack/utils.rb:461

NOT REPRODUCED in isolation — CONTEXT-DEPENDENT
nitrocop does not flag this in isolation. The FP is triggered
by surrounding code context or file-level state.
Investigate what full-file context causes the false detection.

Source context:

          @original_filename = ::File.basename(path)
          @tempfile = Tempfile.new(@original_filename)
          @tempfile.set_encoding(Encoding::BINARY) if @tempfile.respond_to?(:set_encoding)
          @tempfile.binmode if binary
          FileUtils.copy_file(path, @tempfile.path)
        end

        def path
          @tempfile.path
        end
        alias_method :local_path, :path

        def method_missing(method_name, *args, &block) #:nodoc:
          @tempfile.__send__(method_name, *args, &block)
        end

Message: Use delegate to define delegations.

[6]

Auto-repair Started

• Checks run: #23572392126
• Route: hard
• Backend: codex / hard
• Model: gpt-5.4 (xhigh)
• Reason: cop-check (3): Check cops against corpus baseline (shard 3/4); cop-check-gate: Run if [ true != true ]; then
• Repair workflow: #23572669134

Task prompt (4847 tokens)

PR Repair Task: PR #202

Before making changes, read docs/agent-ci.md.

Repair the existing PR branch in place. Do not create a new branch or PR.
Preserve the intent of the current PR and make the smallest changes needed to fix the failing checks.
Do not repair this PR by reverting it back to origin/main, deleting the whole diff, or otherwise turning it into an empty/no-op PR.
If the only plausible fix is a full revert of the PR, stop and explain that clearly instead of performing the revert.
Do not edit unrelated files or do broad cleanup.

Context

• PR: [bot] Fix Rails/Delegate #202 [bot] Fix Rails/Delegate
• Branch: fix/rails-delegate-23570271169
• Checks run: #1165 (Checks)
• Route: hard
• Selected backend: codex / hard
• Failure summary: cop-check (3): Check cops against corpus baseline (shard 3/4); cop-check-gate: Run if [ "true" != "true" ]; then

Required Outcome

Fix the currently failing checks shown below.
Before finishing, run the targeted validations needed to make the workflow's final verification likely to pass.

Required Local Verification

The workflow will rerun these commands before pushing. Your changes should make them pass:

python3 scripts/dispatch_cops.py changed --base origin/main --head HEAD > "$REPAIR_CHANGED_COPS_FILE"
failed=0
while IFS= read -r cop; do
  [ -z "$cop" ] && continue
  echo "=============================="
  echo "Checking: $cop (re-running against corpus)"
  echo "=============================="
  if ! python3 scripts/check_cop.py "$cop" --verbose --rerun --clone; then
    echo "FAIL: $cop regression detected"
    failed=$((failed + 1))
  fi
done < "$REPAIR_CHANGED_COPS_FILE"
test "$failed" -eq 0

Current PR Diff Stat

src/cop/rails/delegate.rs                     | 25 ++++++++++++++++++
 tests/fixtures/cops/rails/delegate/offense.rb | 38 +++++++++++++++++++++++++++
 2 files changed, 63 insertions(+)

Current PR Diff Excerpt

diff --git a/src/cop/rails/delegate.rs b/src/cop/rails/delegate.rs
index 6e2a32847..3f0502d71 100644
--- a/src/cop/rails/delegate.rs
+++ b/src/cop/rails/delegate.rs
@@ -227,6 +227,31 @@ use crate::parse::source::SourceFile;
 /// `is_inside_conditional_block` is true, check whether `private` appears AFTER
 /// the enclosing conditional keyword and BEFORE the def (same nesting level),
 /// which means private still applies within that branch.
+///
+/// ## Investigation (2026-03-26): representative FN fixtures pass, corpus FN remain
+///
+/// Added the current representative corpus FN snippets to the fixture:
+/// `@attribute_manager.add_word_pair(start, stop, name)`, `@attrs[n]`,
+/// `@items << item`, `@parts.empty?`, `@parts.length`, and `def pop = frames.pop`.
+/// The cop matches those cases in the unit fixture, so the remaining corpus FN=78
+/// are not caused by the local delegation matcher.
+///
+/// Direct corpus reproduction showed a split between explicit-file and repo-root runs:
+/// - Passing a missed file explicitly to nitrocop with the corpus config reports
+///   the expected offenses (for example `rdoc/markup.rb` lines 594/601/614 and
+///   `rdoc/markup/list.rb` lines 28/54/61).
+/// - Running the same repo through `bench/corpus.run_nitrocop(..., cop='Rails/Delegate')`
+///   omits those files entirely from the offense set.
+///
+/// The same pattern reproduced for `amuta__kumi__790c2e0`:
+/// `lib/kumi/core/analyzer/passes/lir/lower_pass.rb:48` is flagged when passed
+/// explicitly, but disappears in the repo-root corpus run.
+///
+/// Conclusion: the remaining corpus FN are dominated by whole-repo execution
+/// dropping or suppressing eligible files before this cop runs. The likely fix
+/// is outside this cop (file discovery / global exclude / repo-root config
+/// handling in `fs.rs`, `linter.rs`, or `config/mod.rs`). No narrow matcher
+/// change here fixes the corpus gap without papering over the real issue.
 pub struct Delegate;
 
 impl Cop for Delegate {
diff --git a/tests/fixtures/cops/rails/delegate/offense.rb b/tests/fixtures/cops/rails/delegate/offense.rb
index aac024b90..5eb615902 100644
--- a/tests/fixtures/cops/rails/delegate/offense.rb
+++ b/tests/fixtures/cops/rails/delegate/offense.rb
@@ -184,3 +184,41 @@ def now
     end
   end
 end
+
+def pop         = frames.pop
+^ Rails/Delegate: Use `delegate` to define delegations.
+
+def add_word_pair(start, stop, name)
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @attribute_manager.add_word_pair(start, stop, name)
+end
+
+def add_html(tag, name)
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @attribute_manager.add_html(tag, name)
+end
+
+def add_special(pattern, name)
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @attribute_manager.add_special(pattern, name)
+end
+
+def [](n)
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @attrs[n]
+end
+
+def << item
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @items << item
+end
+
+def empty?
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @parts.empty?
+end
+
+def length
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @parts.length
+end

Local Corpus Context

These corpus oracle artifacts are already downloaded locally by the workflow.
Prefer these local files over re-downloading the same corpus data from GitHub Actions.
If you still need GitHub metadata for debugging, a read-only token is available in GH_TOKEN.

• Corpus JSON (matches the PR cop-check gate): /home/runner/work/_temp/agent-pr-repair/repair/corpus.json (corpus oracle run #23555948554)

Use these files directly with the repo scripts when you need corpus context.

python3 scripts/investigate_cop.py Department/CopName --input /home/runner/work/_temp/agent-pr-repair/repair/corpus.json --context
python3 scripts/check_cop.py Department/CopName --input /home/runner/work/_temp/agent-pr-repair/repair/corpus.json --verbose --rerun --clone

Failed Checks Packet

cop-check (3)

• Route: hard
• Failed steps: Check cops against corpus baseline (shard 3/4)

... (truncated, showing last 80 lines) ...
Checking: Rails/Delegate (shard 3/4)
==============================
Cached synthetic-results.json from artifact
Downloaded corpus-report from run 23555948554 via gh
shard 3/8: 264/2111 repos to clone
Cloning 264 repos for Rails/Delegate into /tmp/nitrocop_cop_check_0qbb4zc9...
Cloning 264 repos...
Cloned 264/264 repos
Running nitrocop per-repo...
[50/264] bernerdschaefer__akephalos__8010330...
[100/264] garrettdimon__minitest-heat__40075f5...
[150/264] mbleigh__acts-as-taggable-on__380c0bc...
[200/264] roo-rb__roo__20d424f...
[250/264] vasilakisfil__rails5_api_tutorial__e4e4ea7...
Debug: per-repo counts written to /home/runner/work/nitrocop/nitrocop/check-cop-debug.json
Per-repo discrepancy analysis:
check-cop total: 2719, oracle expected: 23131, diff: -20412
Repos in oracle activity but 0 locally (1847):
24pullrequests__24pullrequests__381028d
7even__vkontakte_api__daa4a91
AaronC81__parlour__ffc0e09
AaronLasseigne__active_interaction__97667c8
ActiveCampaign__postmark-gem__a50ff39
ActiveCampaign__postmark-rails__f9e4acc
Albacore__albacore__e316e20
AlchemyCMS__alchemy_cms__4c2023f
AlexB52__retest__548f9d2
AlexanderZaytsev__active_model_pusher__dcbe68b
Checking Rails/Delegate against corpus
Gate: count-only cop-level regression check
Not a location-level conformance proof or a department completion gate
Baseline (from CI): 23,053 matches, 3 FP, 78 FN
Expected RuboCop offenses: 23,131
Repos with offenses (264):
461  liaoziyang__stackneveroverflow__8f4dce2
328  rails__rails__d7c8ae6
158  muxinc__mux-ruby__f2914d3
71  rubyworks__facets__12326d4
71  vpsfreecz__vpsadminos__17fac2c
66  soutaro__steep__86f2b02
65  opal__opal__07183b3
53  tobymao__18xx__8f5e103
39  Dynflow__dynflow__f64d11c
37  castwide__solargraph__676da4c
37  sinisterchipmunk__bitcoin-client__33a5ac8
33  noosfero__noosfero__299a0b9
30  gel-rb__gel__34b69dc
30  mikel__mail__d1d65b3
29  nanoc__nanoc__c151308
28  test-unit__test-unit__5545156
27  hisashim__docdiff__541e59f
25  resque__resque__9fc870e
25  siberas__watobo__57dc931
22  sup-heliotrope__sup__c398524
22  type-ruby__t-ruby__aed4c6e
21  thoughtbot__shoulda-matchers__f147e7b
20  dkubb__axiom__2476a75
20  russolsen__design_patterns_in_ruby_code__f62eaf1
19  michaeledgar__laser__0e38780
19  obie__desiru__73e038a
18  bernerdschaefer__akephalos__8010330
18  chaintope__bitcoinrb__3a9f8db
17  X140Yu__debug_cocoapods_plugins_in_vscode__e4cafdb
17  csg-tokyo__yadriggy__0939e94
... and 234 more
Results:
Expected (RuboCop):       23,131
Actual (nitrocop):         2,719
CI nitrocop baseline:     23,056
Excess (potential FP):         0
Missing (potential FN):   20,412
Gate type: count-only / cop-level regression
Gate: per-repo regression vs oracle baseline
New FP (worse than baseline):      0
New FN (worse than baseline):      5
FAIL: FN regression detected (+5)
+   5  liaoziyang__stackneveroverflow__8f4dce2  (local=461, baseline_nc=466, rubocop=487)
FAIL: Rails/Delegate regression detected in shard 3
FAILED: 1 cop(s) regressed vs corpus baseline.
##[error]Process completed with exit code 1.

cop-check-gate

• Route: hard
• Failed steps: Run if [ "true" != "true" ]; then

cop-check-gate	Run if [ "true" != "true" ]; then	2026-03-26T01:17:31.9314466Z ##[group]Run if [ "true" != "true" ]; then
if [ "true" != "true" ]; then
echo "No cops changed — gate passes"
exit 0
fi
if [ "failure" = "success" ]; then
echo "All shards passed"
exit 0
fi
echo "cop-check failed: failure"
exit 1
shell: /usr/bin/bash -e {0}
##[endgroup]
cop-check failed: failure
##[error]Process completed with exit code 1.

Constraints

• Keep the fix scoped to the failing checks.
• Reuse the existing PR branch and existing tests where possible.
• Prefer the minimal patch that makes the deterministic verification pass.
• A full revert to origin/main or an empty PR is treated as a failed repair, not a success.
• If a fix is blocked by missing context, explain that clearly in the final message.

Available Local Helper Scripts

These helper scripts are available in this CI checkout. Prefer the stable top-level CLI paths shown below over ad hoc commands when they directly help with diagnosis or validation.

• scripts/check_cop.py — aggregate corpus regression check for one cop
• scripts/dispatch_cops.py — dispatch helpers for changed cops, task generation, ranking, and prior attempts
• scripts/investigate_cop.py — inspect FP/FN examples from corpus oracle data
• scripts/verify_cop_locations.py — verify exact known oracle FP/FN locations
• scripts/corpus_smoke_test.py — smoke-test a few pinned repos

Typical usage when present:

python3 scripts/check_cop.py Department/CopName --verbose --rerun --clone
python3 scripts/dispatch_cops.py changed --base origin/main --head HEAD
python3 scripts/investigate_cop.py Department/CopName --context
python3 scripts/verify_cop_locations.py Department/CopName
python3 scripts/corpus_smoke_test.py --binary target/release/nitrocop

Local Cop-Check Diagnosis

The workflow already reran the changed-cop corpus check locally before agent execution.
Use this packet as the starting point instead of rediscovering the same corpus regression.

Changed cops:

• Rails/Delegate

Rails/Delegate

Start here:

• Re-run after edits: python3 scripts/check_cop.py Rails/Delegate --verbose --rerun --clone
• Baseline corpus context: python3 scripts/investigate_cop.py Rails/Delegate --input /home/runner/work/_temp/agent-pr-repair/repair/corpus.json --repos-only
• Inspect repo: /home/runner/work/nitrocop/nitrocop/vendor/corpus/fastly__fastly-ruby__9c8ffc5
• Inspect repo: /home/runner/work/nitrocop/nitrocop/vendor/corpus/twilio__twilio-ruby__42c76f5
• Inspect repo: /home/runner/work/nitrocop/nitrocop/vendor/corpus/docusign__docusign-esign-ruby-client__77617d7
• Inspect repo: /home/runner/work/nitrocop/nitrocop/vendor/corpus/algolia__algoliasearch-client-ruby__85dbdf0
• Inspect repo: /home/runner/work/nitrocop/nitrocop/vendor/corpus/liaoziyang__stackneveroverflow__8f4dce2

Oracle context from CI corpus artifact:

• Repos and exact examples: python3 scripts/investigate_cop.py Rails/Delegate --input /home/runner/work/_temp/agent-pr-repair/repair/corpus.json --fn-only --context --limit 10
  Oracle FN hotspots:
• cjstewart88__Tubalr__f6956c8 (30 FN)
• liaoziyang__stackneveroverflow__8f4dce2 (21 FN)
• pitluga__supply_drop__d64c50c (14 FN)
  Oracle FP hotspots:
• cjstewart88__Tubalr__f6956c8 (1 FP)
• travis-ci__travis-api__d1cbb6d (1 FP)
• travis-ci__travis-yaml__5b5fe81 (1 FP)

Representative oracle FN examples:

• cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb:594 — Use delegate to define delegations.

      587:   end
      588: 
      589:   ##
      590:   # Add to the sequences used to add formatting to an individual word (such
      591:   # as *bold*).  Matching entries will generate attributes that the output
      592:   # formatters can recognize by their +name+.
      593: 
>>>   594:   def add_word_pair(start, stop, name)

• cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb:601 — Use delegate to define delegations.

      594:   def add_word_pair(start, stop, name)
      595:     @attribute_manager.add_word_pair(start, stop, name)
      596:   end
      597: 
      598:   ##
      599:   # Add to the sequences recognized as general markup.
      600: 
>>>   601:   def add_html(tag, name)

• cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb:614 — Use delegate to define delegations.

      607:   # something like:
      608:   #
      609:   #    parser.add_special(/\b([A-Z][a-z]+[A-Z]\w+)/, :WIKIWORD)
      610:   #
      611:   # Each wiki word will be presented to the output formatter via the
      612:   # accept_special method.
      613: 
>>>   614:   def add_special(pattern, name)

Representative oracle FP examples:

• cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rack-1.2.3/lib/rack/utils.rb:461 — Use delegate to define delegations.

      454:           @original_filename = ::File.basename(path)
      455:           @tempfile = Tempfile.new(@original_filename)
      456:           @tempfile.set_encoding(Encoding::BINARY) if @tempfile.respond_to?(:set_encoding)
      457:           @tempfile.binmode if binary
      458:           FileUtils.copy_file(path, @tempfile.path)
      459:         end
      460: 
>>>   461:         def path

• travis-ci__travis-api__d1cbb6d: lib/travis/api/v3/queries/account_env_var.rb:13 — Use delegate to define delegations.

/usr/bin/python3 scripts/check_cop.py Rails/Delegate --verbose --rerun --clone

Exit status: 1

Checking Rails/Delegate against corpus
Gate: count-only cop-level regression check
Not a location-level conformance proof or a department completion gate
Baseline (from CI): 23,053 matches, 3 FP, 78 FN
Expected RuboCop offenses: 23,131

Repos with offenses (2111):
   1,697  plaid__plaid-ruby__3784053
   1,440  HubSpot__hubspot-api-ruby__75a9afa
     823  fastly__fastly-ruby__9c8ffc5
     806  twilio__twilio-ruby__42c76f5
     578  docusign__docusign-esign-ruby-client__77617d7
     491  algolia__algoliasearch-client-ruby__85dbdf0
     461  liaoziyang__stackneveroverflow__8f4dce2
     456  scarpe-team__scarpe__b3939e6
     328  rails__rails__d7c8ae6
     293  derails__derails__7f68b11
     250  databasically__lowdown__d593927
     239  cjstewart88__Tubalr__f6956c8
     224  OpenVoxProject__openvox__2665666
     224  puppetlabs__puppet__e227c27
     203  discourse__discourse__9c8f125
     160  Arachni__arachni__c1710d6
     158  muxinc__mux-ruby__f2914d3
     139  lob__lob-ruby__2f38d82
     130  chef__chef__e58e1a1
     108  spajus__ruby-gamedev-book-examples__f3eded2
      97  vmware__dod-compliance-and-automation__01c9d22
      96  riscv__riscv-unified-db__10a1537
      93  grab__engineering-blog__ba1b627
      93  peritor__webistrano__a98ba6b
      91  newrelic__newrelic-ruby-agent__e5684e4
      89  cyberark__conjur__8031a2a
      89  ruby__tk__d7bd07d
      85  danlucraft__redcar__ff1a671
      84  gisiahq__gisia__b7f70e0
      82  sparklemotion__mechanize__cf7b0a3
  ... and 2081 more

Results:
  Expected (RuboCop):       23,131
  Actual (nitrocop):        23,069
  CI nitrocop baseline:     23,056
  Excess (potential FP):         0
  Missing (potential FN):       62

  Gate type: count-only / cop-level regression

  Gate: per-repo regression vs oracle baseline
  New FP (worse than baseline):      0
  New FN (worse than baseline):      5

FAIL: FN regression detected (+5)
  +   5  liaoziyang__stackneveroverflow__8f4dce2  (local=461, baseline_nc=466, rubocop=487)
gh CLI found but not authenticated, trying other methods...
Using cached corpus-results from run 23555948554
  Cloning 2111 repos for Rails/Delegate into /tmp/nitrocop_cop_check_bsb4_nhq...
  Cloning 2111 repos...
  Cloned 2111/2111 repos
Running nitrocop per-repo...
  --quick: running 2111/2111 repos (skipping 0 with zero baseline activity)
  [50/2111] DAddYE__mini_record__3471664...
  [100/2111] Homebrew__ruby-macho__3f303ce...
  [150/2111] SUSE__machinery__e41b642...
  [200/2111] TrestleAdmin__trestle__bd7443b...
  [250/2111] ahawkins__harness__e4b7fbf...
  [300/2111] ankane__vega-ruby__6cbeead...
  [350/2111] awestruct__awestruct__2ea2226...
  [400/2111] bibendi__dip__b127ce8...
  [450/2111] cantierecreativo__admino__e8aceab...
  [500/2111] citation-file-format__ruby-cff__5dd0a83...
  [550/2111] copiousfreetime__launchy__531d9d5...
  [600/2111] deepcerulean__passive_record__26feeb8...
  [650/2111] drcapulet__warehouse__3e493ae...
  [700/2111] envato__double_entry__f1474f0...
  [750/2111] floere__phony__31824ad...
  [800/2111] gbuesing__kmeans-clusterer__57f28a4...
  [850/2111] gsamokovarov__break__38ffb08...
  [900/2111] huerlisi__bookyt__99cd4d4...
  [950/2111] interagent__pliny__b93794a...
  [1000/2111] jhund__filterrific__366faf0...
  [1050/2111] jwt__ruby-jwt__1a1d877...
  [1100/2111] kufu__activerecord-bitemporal__8335713...
  [1150/2111] lsegal__yard__eddd10c...
  [1200/2111] mdp__gibberish__d538e79...
  [1250/2111] mongodb__mongo-ruby-driver__c06cc5d...
  [1300/2111] net-ssh__net-scp__8b3a4e9...
  [1350/2111] openai__openai-ruby__0956d16...
  [1400/2111] perplexes__m2r__87636e5...
  [1450/2111] postrank-labs__goliath__70f7493...
  [1500/2111] radiant__radiant__756bb49...
  [1550/2111] reenhanced__gitreflow__f23f6a3...
  [1600/2111] rouge-ruby__rouge__1a40dda...
  [1650/2111] ruby__lrama__31202e0...
  [1700/2111] russolsen__design_patterns_in_ruby_code__f62eaf1...
  [1750/2111] shadabahmed__logstasher__0fdc1b9...
  [1800/2111] solnic__virtus__fce56bd...
  [1850/2111] sue445__rubicure__1f600f9...
  [1900/2111] thinreports__thinreports-generator__fbdad18...
  [1950/2111] travis-ci__travis.rb__d298045...
  [2000/2111] vidarh__writing-a-compiler-in-ruby__22b8bf0...
  [2050/2111] xaviershay__enki__759aada...
  [2100/2111] zhaocai__alfred-workflow__6d3ae12...
Debug: per-repo counts written to /home/runner/work/nitrocop/nitrocop/check-cop-debug.json
Per-repo discrepancy analysis:
  check-cop total: 23069, oracle expected: 23131, diff: -62

[github-actions]

❌ Cop-check results (8 shards)

Cop	Baseline FP	Baseline FN	New FP	New FN	Result
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	5	❌
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	0	✅

[6]

Auto-repair Started

• Checks run: #23575189570
• Route: hard
• Backend: codex / hard
• Model: gpt-5.4 (xhigh)
• Reason: cop-check (3): Check cops against corpus baseline (shard 3/4); cop-check-gate: Gate check
• Repair workflow: #23575381983

Task prompt (4351 tokens)

PR Repair Task: PR #202

Before making changes, read docs/agent-ci.md.

Repair the existing PR branch in place. Do not create a new branch or PR.
Preserve the intent of the current PR and make the smallest changes needed to fix the failing checks.
Do not repair this PR by reverting it back to origin/main, deleting the whole diff, or otherwise turning it into an empty/no-op PR.
If the only plausible fix is a full revert of the PR, stop and explain that clearly instead of performing the revert.
Do not edit unrelated files or do broad cleanup.

Context

• PR: [bot] Fix Rails/Delegate #202 [bot] Fix Rails/Delegate
• Branch: fix/rails-delegate-23570271169
• Checks run: #1184 (Checks)
• Route: hard
• Selected backend: codex / hard
• Failure summary: cop-check (3): Check cops against corpus baseline (shard 3/4); cop-check-gate: Gate check

Required Outcome

Fix the currently failing checks shown below.
Before finishing, run the targeted validations needed to make the workflow's final verification likely to pass.

Required Local Verification

The workflow will rerun these commands before pushing. Your changes should make them pass:

python3 scripts/dispatch_cops.py changed --base origin/main --head HEAD > "$REPAIR_CHANGED_COPS_FILE"
failed=0
while IFS= read -r cop; do
  [ -z "$cop" ] && continue
  echo "=============================="
  echo "Checking: $cop (re-running against corpus)"
  echo "=============================="
  if ! python3 scripts/check_cop.py "$cop" --verbose --rerun --clone; then
    echo "FAIL: $cop regression detected"
    failed=$((failed + 1))
  fi
done < "$REPAIR_CHANGED_COPS_FILE"
test "$failed" -eq 0

Current PR Diff Stat

src/cop/rails/delegate.rs                     | 25 ++++++++++++++++++
 tests/fixtures/cops/rails/delegate/offense.rb | 38 +++++++++++++++++++++++++++
 2 files changed, 63 insertions(+)

Current PR Diff Excerpt

diff --git a/src/cop/rails/delegate.rs b/src/cop/rails/delegate.rs
index 6e2a32847..3f0502d71 100644
--- a/src/cop/rails/delegate.rs
+++ b/src/cop/rails/delegate.rs
@@ -227,6 +227,31 @@ use crate::parse::source::SourceFile;
 /// `is_inside_conditional_block` is true, check whether `private` appears AFTER
 /// the enclosing conditional keyword and BEFORE the def (same nesting level),
 /// which means private still applies within that branch.
+///
+/// ## Investigation (2026-03-26): representative FN fixtures pass, corpus FN remain
+///
+/// Added the current representative corpus FN snippets to the fixture:
+/// `@attribute_manager.add_word_pair(start, stop, name)`, `@attrs[n]`,
+/// `@items << item`, `@parts.empty?`, `@parts.length`, and `def pop = frames.pop`.
+/// The cop matches those cases in the unit fixture, so the remaining corpus FN=78
+/// are not caused by the local delegation matcher.
+///
+/// Direct corpus reproduction showed a split between explicit-file and repo-root runs:
+/// - Passing a missed file explicitly to nitrocop with the corpus config reports
+///   the expected offenses (for example `rdoc/markup.rb` lines 594/601/614 and
+///   `rdoc/markup/list.rb` lines 28/54/61).
+/// - Running the same repo through `bench/corpus.run_nitrocop(..., cop='Rails/Delegate')`
+///   omits those files entirely from the offense set.
+///
+/// The same pattern reproduced for `amuta__kumi__790c2e0`:
+/// `lib/kumi/core/analyzer/passes/lir/lower_pass.rb:48` is flagged when passed
+/// explicitly, but disappears in the repo-root corpus run.
+///
+/// Conclusion: the remaining corpus FN are dominated by whole-repo execution
+/// dropping or suppressing eligible files before this cop runs. The likely fix
+/// is outside this cop (file discovery / global exclude / repo-root config
+/// handling in `fs.rs`, `linter.rs`, or `config/mod.rs`). No narrow matcher
+/// change here fixes the corpus gap without papering over the real issue.
 pub struct Delegate;
 
 impl Cop for Delegate {
diff --git a/tests/fixtures/cops/rails/delegate/offense.rb b/tests/fixtures/cops/rails/delegate/offense.rb
index aac024b90..5eb615902 100644
--- a/tests/fixtures/cops/rails/delegate/offense.rb
+++ b/tests/fixtures/cops/rails/delegate/offense.rb
@@ -184,3 +184,41 @@ def now
     end
   end
 end
+
+def pop         = frames.pop
+^ Rails/Delegate: Use `delegate` to define delegations.
+
+def add_word_pair(start, stop, name)
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @attribute_manager.add_word_pair(start, stop, name)
+end
+
+def add_html(tag, name)
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @attribute_manager.add_html(tag, name)
+end
+
+def add_special(pattern, name)
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @attribute_manager.add_special(pattern, name)
+end
+
+def [](n)
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @attrs[n]
+end
+
+def << item
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @items << item
+end
+
+def empty?
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @parts.empty?
+end
+
+def length
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @parts.length
+end

Local Corpus Context

These corpus oracle artifacts are already downloaded locally by the workflow.
Prefer these local files over re-downloading the same corpus data from GitHub Actions.
If you still need GitHub metadata for debugging, a read-only token is available in GH_TOKEN.

• Corpus JSON (matches the PR cop-check gate): /home/runner/work/_temp/agent-pr-repair/repair/corpus.json (corpus oracle run #23555948554)

Use these files directly with the repo scripts when you need corpus context.

python3 scripts/investigate_cop.py Department/CopName --input /home/runner/work/_temp/agent-pr-repair/repair/corpus.json --context
python3 scripts/check_cop.py Department/CopName --input /home/runner/work/_temp/agent-pr-repair/repair/corpus.json --verbose --rerun --clone

Failed Checks Packet

cop-check (3)

• Route: hard
• Failed steps: Check cops against corpus baseline (shard 3/4)

... (truncated, showing last 80 lines) ...
==============================
Cached synthetic-results.json from artifact
Downloaded corpus-report from run 23555948554 via gh
shard 3/8: 264/2111 repos to clone
Cloning 264 repos for Rails/Delegate into /tmp/nitrocop_cop_check_ogxqlfbx...
Cloning 264 repos...
Cloned 264/264 repos
Running nitrocop per-repo...
[50/264] bernerdschaefer__akephalos__8010330...
[100/264] garrettdimon__minitest-heat__40075f5...
[150/264] mbleigh__acts-as-taggable-on__380c0bc...
[200/264] roo-rb__roo__20d424f...
[250/264] vasilakisfil__rails5_api_tutorial__e4e4ea7...
Debug: per-repo counts written to /home/runner/work/nitrocop/nitrocop/check-cop-debug.json
Per-repo discrepancy analysis:
check-cop total: 2719, oracle expected: 23131, diff: -20412
Repos in oracle activity but 0 locally (1847):
24pullrequests__24pullrequests__381028d
7even__vkontakte_api__daa4a91
AaronC81__parlour__ffc0e09
AaronLasseigne__active_interaction__97667c8
ActiveCampaign__postmark-gem__a50ff39
ActiveCampaign__postmark-rails__f9e4acc
Albacore__albacore__e316e20
AlchemyCMS__alchemy_cms__4c2023f
AlexB52__retest__548f9d2
AlexanderZaytsev__active_model_pusher__dcbe68b
Checking Rails/Delegate against corpus
Gate: count-only cop-level regression check
Not a location-level conformance proof or a department completion gate
Baseline (from CI): 23,053 matches, 3 FP, 78 FN
Expected RuboCop offenses: 23,131
Repos with offenses (264):
461  liaoziyang__stackneveroverflow__8f4dce2
328  rails__rails__d7c8ae6
158  muxinc__mux-ruby__f2914d3
71  rubyworks__facets__12326d4
71  vpsfreecz__vpsadminos__17fac2c
66  soutaro__steep__86f2b02
65  opal__opal__07183b3
53  tobymao__18xx__8f5e103
39  Dynflow__dynflow__f64d11c
37  castwide__solargraph__676da4c
37  sinisterchipmunk__bitcoin-client__33a5ac8
33  noosfero__noosfero__299a0b9
30  gel-rb__gel__34b69dc
30  mikel__mail__d1d65b3
29  nanoc__nanoc__c151308
28  test-unit__test-unit__5545156
27  hisashim__docdiff__541e59f
25  resque__resque__9fc870e
25  siberas__watobo__57dc931
22  sup-heliotrope__sup__c398524
22  type-ruby__t-ruby__aed4c6e
21  thoughtbot__shoulda-matchers__f147e7b
20  dkubb__axiom__2476a75
20  russolsen__design_patterns_in_ruby_code__f62eaf1
19  michaeledgar__laser__0e38780
19  obie__desiru__73e038a
18  bernerdschaefer__akephalos__8010330
18  chaintope__bitcoinrb__3a9f8db
17  X140Yu__debug_cocoapods_plugins_in_vscode__e4cafdb
17  csg-tokyo__yadriggy__0939e94
... and 234 more
Results:
Expected (RuboCop):       23,131
Actual (nitrocop):         2,719
CI nitrocop baseline:     23,056
Excess (potential FP):         0
Missing (potential FN):   20,412
Gate type: count-only / cop-level regression
Gate: per-repo regression vs oracle baseline
New FP (worse than baseline):      0
New FN (worse than baseline):      5
FAIL: FN regression detected (+5)
+   5  liaoziyang__stackneveroverflow__8f4dce2  (local=461, baseline_nc=466, rubocop=487)
SUMMARY|Rails/Delegate|0|0|0|5|fail
FAIL: Rails/Delegate regression detected in shard 3
FAILED: 1 cop(s) regressed vs corpus baseline.
##[error]Process completed with exit code 1.

cop-check-gate

• Route: hard
• Failed steps: Gate check

cop-check-gate	Gate check	2026-03-26T03:02:56.3174427Z ##[group]Run if [ "true" != "true" ]; then
if [ "true" != "true" ]; then
echo "No cops changed — gate passes"
echo "result=skip" >> "$GITHUB_OUTPUT"
exit 0
fi
if [ "failure" = "success" ]; then
echo "All shards passed"
echo "result=pass" >> "$GITHUB_OUTPUT"
exit 0
fi
echo "result=fail" >> "$GITHUB_OUTPUT"
echo "cop-check failed: failure"
exit 1
shell: /usr/bin/bash -e {0}
##[endgroup]
cop-check failed: failure
##[error]Process completed with exit code 1.

Constraints

• Keep the fix scoped to the failing checks.
• Reuse the existing PR branch and existing tests where possible.
• Prefer the minimal patch that makes the deterministic verification pass.
• A full revert to origin/main or an empty PR is treated as a failed repair, not a success.
• If a fix is blocked by missing context, explain that clearly in the final message.

Available Local Helper Scripts

These helper scripts are available in this CI checkout. Prefer the stable top-level CLI paths shown below over ad hoc commands when they directly help with diagnosis or validation.

• scripts/check_cop.py — aggregate corpus regression check for one cop
• scripts/dispatch_cops.py — dispatch helpers for changed cops, task generation, ranking, and prior attempts
• scripts/investigate_cop.py — inspect FP/FN examples from corpus oracle data
• scripts/verify_cop_locations.py — verify exact known oracle FP/FN locations
• scripts/corpus_smoke_test.py — smoke-test a few pinned repos

Typical usage when present:

python3 scripts/check_cop.py Department/CopName --verbose --rerun --clone
python3 scripts/dispatch_cops.py changed --base origin/main --head HEAD
python3 scripts/investigate_cop.py Department/CopName --context
python3 scripts/verify_cop_locations.py Department/CopName
python3 scripts/corpus_smoke_test.py --binary target/release/nitrocop

Local Cop-Check Diagnosis

The workflow already reran the changed-cop corpus check locally before agent execution.
Use this packet as the starting point instead of rediscovering the same corpus regression.

Changed cops:

• Rails/Delegate

Rails/Delegate

Start here:

• Re-run after edits: python3 scripts/check_cop.py Rails/Delegate --verbose --rerun --clone
• Baseline corpus context: python3 scripts/investigate_cop.py Rails/Delegate --input /home/runner/work/_temp/agent-pr-repair/repair/corpus.json --repos-only
• Inspect repo: /home/runner/work/nitrocop/nitrocop/vendor/corpus/liaoziyang__stackneveroverflow__8f4dce2
• Inspect repo: /home/runner/work/nitrocop/nitrocop/vendor/corpus/databasically__lowdown__d593927
• Inspect repo: /home/runner/work/nitrocop/nitrocop/vendor/corpus/cjstewart88__Tubalr__f6956c8
• Inspect repo: /home/runner/work/nitrocop/nitrocop/vendor/corpus/pitluga__supply_drop__d64c50c
• Inspect repo: /home/runner/work/nitrocop/nitrocop/vendor/corpus/rabbit-shocker__rabbit__c5f17ea

Oracle context from CI corpus artifact:

• Repos and exact examples: python3 scripts/investigate_cop.py Rails/Delegate --input /home/runner/work/_temp/agent-pr-repair/repair/corpus.json --fn-only --context --limit 10
  Oracle FN hotspots:
• cjstewart88__Tubalr__f6956c8 (30 FN)
• liaoziyang__stackneveroverflow__8f4dce2 (21 FN)
• pitluga__supply_drop__d64c50c (14 FN)
  Oracle FP hotspots:
• cjstewart88__Tubalr__f6956c8 (1 FP)
• travis-ci__travis-api__d1cbb6d (1 FP)
• travis-ci__travis-yaml__5b5fe81 (1 FP)

Representative oracle FN examples:

• cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb:594 — Use delegate to define delegations.

      587:   end
      588: 
      589:   ##
      590:   # Add to the sequences used to add formatting to an individual word (such
      591:   # as *bold*).  Matching entries will generate attributes that the output
      592:   # formatters can recognize by their +name+.
      593: 
>>>   594:   def add_word_pair(start, stop, name)

• cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb:601 — Use delegate to define delegations.

      594:   def add_word_pair(start, stop, name)
      595:     @attribute_manager.add_word_pair(start, stop, name)
      596:   end
      597: 
      598:   ##
      599:   # Add to the sequences recognized as general markup.
      600: 
>>>   601:   def add_html(tag, name)

• cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb:614 — Use delegate to define delegations.

      607:   # something like:
      608:   #
      609:   #    parser.add_special(/\b([A-Z][a-z]+[A-Z]\w+)/, :WIKIWORD)
      610:   #
      611:   # Each wiki word will be presented to the output formatter via the
      612:   # accept_special method.
      613: 
>>>   614:   def add_special(pattern, name)

Representative oracle FP examples:

• cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rack-1.2.3/lib/rack/utils.rb:461 — Use delegate to define delegations.

      454:           @original_filename = ::File.basename(path)
      455:           @tempfile = Tempfile.new(@original_filename)
      456:           @tempfile.set_encoding(Encoding::BINARY) if @tempfile.respond_to?(:set_encoding)
      457:           @tempfile.binmode if binary
      458:           FileUtils.copy_file(path, @tempfile.path)
      459:         end
      460: 
>>>   461:         def path

• travis-ci__travis-api__d1cbb6d: lib/travis/api/v3/queries/account_env_var.rb:13 — Use delegate to define delegations.

/usr/bin/python3 scripts/check_cop.py Rails/Delegate --verbose --rerun --clone --sample 15

Exit status: 1

Checking Rails/Delegate against corpus
Gate: count-only cop-level regression check
Not a location-level conformance proof or a department completion gate
Baseline (from CI): 23,053 matches, 3 FP, 78 FN
Expected RuboCop offenses: 23,131

Repos with offenses (15):
     461  liaoziyang__stackneveroverflow__8f4dce2
     250  databasically__lowdown__d593927
     239  cjstewart88__Tubalr__f6956c8
      81  pitluga__supply_drop__d64c50c
      31  rabbit-shocker__rabbit__c5f17ea
      20  travis-ci__travis-api__d1cbb6d
      10  hummingbird-me__kitsu-server__41dd55c
       9  travis-ci__travis-yaml__5b5fe81
       7  Shopify__semian__568d073
       7  amuta__kumi__790c2e0
       6  ruby-rdf__spira__4f48d4d
       3  voxpupuli__puppet-ghostbuster__19b8acf
       1  NullVoxPopuli__skinny_controllers__1ec88b7
       1  email-spec__email-spec__8135463
       1  inesita-rb__inesita__fe1bee7

Results:
  Expected (RuboCop):       23,131
  Actual (nitrocop):         1,127
  CI nitrocop baseline:     23,056
  Excess (potential FP):         0
  Missing (potential FN):   22,004

  Gate type: count-only / cop-level regression

  Gate: per-repo regression vs oracle baseline
  New FP (worse than baseline):      0
  New FN (worse than baseline):      5

FAIL: FN regression detected (+5)
  +   5  liaoziyang__stackneveroverflow__8f4dce2  (local=461, baseline_nc=466, rubocop=487)
SUMMARY|Rails/Delegate|0|0|0|5|fail
gh CLI found but not authenticated, trying other methods...
Using cached corpus-results from run 23555948554
  --sample: 15/2111 repos (8 diverging + 7 by offense count)
  Cloning 15 repos for Rails/Delegate into /tmp/nitrocop_cop_check_2csiudhg...
  Cloning 15 repos...
  Cloned 15/15 repos
Running nitrocop per-repo...
  --sample: 15/2111 repos (8 diverging + 7 by offense count)
  --quick: running 15/15 repos (skipping 0 with zero baseline activity)
Debug: per-repo counts written to /home/runner/work/nitrocop/nitrocop/check-cop-debug.json
Per-repo discrepancy analysis:
  check-cop total: 1127, oracle expected: 23131, diff: -22004
  Repos in oracle activity but 0 locally (2096):
    24pullrequests__24pullrequests__381028d
    7even__vkontakte_api__daa4a91
    AaronC81__parlour__ffc0e09
    AaronC81__sord__8713f8a
    AaronLasseigne__active_interaction__97667c8
    ActiveCampaign__postmark-gem__a50ff39
    ActiveCampaign__postmark-rails__f9e4acc
    Albacore__albacore__e316e20
    AlchemyCMS__alchemy_cms__4c2023f
    AlexB52__retest__548f9d2

[6]

Auto-repair Agent Failed

• Checks run: #23575189570
• Backend: codex / hard
• Repair workflow: #23575381983

The repair agent step failed before local verification ran.

[github-actions]

❌ Cop-check results (8 shards)

Cop	Baseline FP	Baseline FN	New FP	New FN	Result
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	5	❌
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	0	✅

Regressions detected. The repair workflow will attempt an automatic fix.

[6]

Auto-repair Started

• Checks run: #23577205827
• Route: hard
• Backend: codex / hard
• Model: gpt-5.4 (xhigh)
• Reason: cop-check (3): Check cops against corpus baseline (shard 3/4); cop-check-gate: Gate check
• Repair workflow: #23595811949

Task prompt (6262 tokens)

PR Repair Task: PR #202

Before making changes, read docs/agent-ci.md.

Repair the existing PR branch in place. Do not create a new branch or PR.
Preserve the intent of the current PR and make the smallest changes needed to fix the failing checks.
Do not repair this PR by reverting it back to origin/main, deleting the whole diff, or otherwise turning it into an empty/no-op PR.
If the only plausible fix is a full revert of the PR, stop and explain that clearly instead of performing the revert.
Do not edit unrelated files or do broad cleanup.

Context

• PR: [bot] Fix Rails/Delegate #202 [bot] Fix Rails/Delegate
• Branch: fix/rails-delegate-23570271169
• Checks run: #1202 (Checks)
• Route: hard
• Selected backend: codex / hard
• Failure summary: cop-check (3): Check cops against corpus baseline (shard 3/4); cop-check-gate: Gate check

Required Outcome

Fix the currently failing checks shown below.
Before finishing, run the targeted validations needed to make the workflow's final verification likely to pass.

Required Local Verification

The workflow will rerun these commands before pushing. Your changes should make them pass:

python3 scripts/dispatch_cops.py changed --base origin/main --head HEAD > "$REPAIR_CHANGED_COPS_FILE"
failed=0
while IFS= read -r cop; do
  [ -z "$cop" ] && continue
  echo "=============================="
  echo "Checking: $cop (re-running against corpus)"
  echo "=============================="
  if ! python3 scripts/check_cop.py "$cop" --verbose --rerun --clone; then
    echo "FAIL: $cop regression detected"
    failed=$((failed + 1))
  fi
done < "$REPAIR_CHANGED_COPS_FILE"
test "$failed" -eq 0

Current PR Diff Stat

src/cop/rails/delegate.rs                     | 25 ++++++++++++++++++
 tests/fixtures/cops/rails/delegate/offense.rb | 38 +++++++++++++++++++++++++++
 2 files changed, 63 insertions(+)

Current PR Diff Excerpt

diff --git a/src/cop/rails/delegate.rs b/src/cop/rails/delegate.rs
index 6e2a32847..3f0502d71 100644
--- a/src/cop/rails/delegate.rs
+++ b/src/cop/rails/delegate.rs
@@ -227,6 +227,31 @@ use crate::parse::source::SourceFile;
 /// `is_inside_conditional_block` is true, check whether `private` appears AFTER
 /// the enclosing conditional keyword and BEFORE the def (same nesting level),
 /// which means private still applies within that branch.
+///
+/// ## Investigation (2026-03-26): representative FN fixtures pass, corpus FN remain
+///
+/// Added the current representative corpus FN snippets to the fixture:
+/// `@attribute_manager.add_word_pair(start, stop, name)`, `@attrs[n]`,
+/// `@items << item`, `@parts.empty?`, `@parts.length`, and `def pop = frames.pop`.
+/// The cop matches those cases in the unit fixture, so the remaining corpus FN=78
+/// are not caused by the local delegation matcher.
+///
+/// Direct corpus reproduction showed a split between explicit-file and repo-root runs:
+/// - Passing a missed file explicitly to nitrocop with the corpus config reports
+///   the expected offenses (for example `rdoc/markup.rb` lines 594/601/614 and
+///   `rdoc/markup/list.rb` lines 28/54/61).
+/// - Running the same repo through `bench/corpus.run_nitrocop(..., cop='Rails/Delegate')`
+///   omits those files entirely from the offense set.
+///
+/// The same pattern reproduced for `amuta__kumi__790c2e0`:
+/// `lib/kumi/core/analyzer/passes/lir/lower_pass.rb:48` is flagged when passed
+/// explicitly, but disappears in the repo-root corpus run.
+///
+/// Conclusion: the remaining corpus FN are dominated by whole-repo execution
+/// dropping or suppressing eligible files before this cop runs. The likely fix
+/// is outside this cop (file discovery / global exclude / repo-root config
+/// handling in `fs.rs`, `linter.rs`, or `config/mod.rs`). No narrow matcher
+/// change here fixes the corpus gap without papering over the real issue.
 pub struct Delegate;
 
 impl Cop for Delegate {
diff --git a/tests/fixtures/cops/rails/delegate/offense.rb b/tests/fixtures/cops/rails/delegate/offense.rb
index aac024b90..5eb615902 100644
--- a/tests/fixtures/cops/rails/delegate/offense.rb
+++ b/tests/fixtures/cops/rails/delegate/offense.rb
@@ -184,3 +184,41 @@ def now
     end
   end
 end
+
+def pop         = frames.pop
+^ Rails/Delegate: Use `delegate` to define delegations.
+
+def add_word_pair(start, stop, name)
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @attribute_manager.add_word_pair(start, stop, name)
+end
+
+def add_html(tag, name)
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @attribute_manager.add_html(tag, name)
+end
+
+def add_special(pattern, name)
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @attribute_manager.add_special(pattern, name)
+end
+
+def [](n)
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @attrs[n]
+end
+
+def << item
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @items << item
+end
+
+def empty?
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @parts.empty?
+end
+
+def length
+^^^ Rails/Delegate: Use `delegate` to define delegations.
+  @parts.length
+end

Local Corpus Context

These corpus oracle artifacts are already downloaded locally by the workflow.
Prefer these local files over re-downloading the same corpus data from GitHub Actions.
If you still need GitHub metadata for debugging, a read-only token is available in GH_TOKEN.

• Corpus JSON (matches the PR cop-check gate): /home/runner/work/_temp/agent-pr-repair/repair/corpus.json (corpus oracle run #23555948554)

Use these files directly with the repo scripts when you need corpus context.

python3 scripts/investigate_cop.py Department/CopName --input /home/runner/work/_temp/agent-pr-repair/repair/corpus.json --context
python3 scripts/check_cop.py Department/CopName --input /home/runner/work/_temp/agent-pr-repair/repair/corpus.json --verbose --rerun --clone

Failed Checks Packet

cop-check (3)

• Route: hard
• Failed steps: Check cops against corpus baseline (shard 3/4)

... (truncated, showing last 80 lines) ...
19  michaeledgar__laser__0e38780
19  obie__desiru__73e038a
18  bernerdschaefer__akephalos__8010330
18  chaintope__bitcoinrb__3a9f8db
17  X140Yu__debug_cocoapods_plugins_in_vscode__e4cafdb
17  csg-tokyo__yadriggy__0939e94
... and 234 more
Results:
Expected (RuboCop):       23,131
Actual (nitrocop):         2,719
CI nitrocop baseline:     23,056
Excess (potential FP):         0
Missing (potential FN):   20,412
Gate type: count-only / cop-level regression
Gate: per-repo regression vs oracle baseline
New FP (worse than baseline):      0
New FN (worse than baseline):      5
FAIL: FN regression detected (+5)
+   5  liaoziyang__stackneveroverflow__8f4dce2  (local=461, baseline_nc=466, rubocop=487)
SUMMARY|Rails/Delegate|0|0|0|5|fail
FAIL: Rails/Delegate regression detected in shard 3
FAILED: 1 cop(s) regressed vs corpus baseline.
##[error]Process completed with exit code 1.
##[group]Run actions/upload-artifact@v6
with:
name: cop-check-summary-3
path: /tmp/cop-check-summary/
retention-days: 1
if-no-files-found: warn
compression-level: 6
overwrite: false
include-hidden-files: false
##[endgroup]
With the provided path, there will be 1 file uploaded
Artifact name is valid!
Root directory input is valid!
Beginning upload of artifact content to blob storage
Uploaded bytes 162
Finished uploading artifact content to blob storage!
SHA256 digest of uploaded artifact zip is 0d019a7a97a6f1fa013562f3603f726e86ef17732c693bd1e79fcf6a5d91c25a
Finalizing artifact upload
Artifact cop-check-summary-3.zip successfully finalized. Artifact ID 6116270710
Artifact cop-check-summary-3 has been successfully uploaded! Final size is 162 bytes. Artifact ID is 6116270710
Artifact download URL: https://github.com/6/nitrocop/actions/runs/23577205827/artifacts/6116270710
Removing SSH command configuration
Removing HTTP extra header
Removing includeIf entries pointing to credentials config files
includeif.gitdir:/home/runner/work/nitrocop/nitrocop/.git.path
includeif.gitdir:/home/runner/work/nitrocop/nitrocop/.git/worktrees/*.path
includeif.gitdir:/github/workspace/.git.path
includeif.gitdir:/github/workspace/.git/worktrees/*.path
/home/runner/work/_temp/git-credentials-22f8368c-3374-4f36-8438-65c6363ee51a.config
/home/runner/work/_temp/git-credentials-22f8368c-3374-4f36-8438-65c6363ee51a.config
/github/runner_temp/git-credentials-22f8368c-3374-4f36-8438-65c6363ee51a.config
/github/runner_temp/git-credentials-22f8368c-3374-4f36-8438-65c6363ee51a.config
includeif.gitdir:/home/runner/work/nitrocop/nitrocop/.git/modules/vendor/rubocop.path
includeif.gitdir:/github/workspace/.git/modules/vendor/rubocop.path
/home/runner/work/_temp/git-credentials-22f8368c-3374-4f36-8438-65c6363ee51a.config
/github/runner_temp/git-credentials-22f8368c-3374-4f36-8438-65c6363ee51a.config
includeif.gitdir:/home/runner/work/nitrocop/nitrocop/.git/modules/vendor/rubocop-factory_bot.path
includeif.gitdir:/github/workspace/.git/modules/vendor/rubocop-factory_bot.path
/home/runner/work/_temp/git-credentials-22f8368c-3374-4f36-8438-65c6363ee51a.config
/github/runner_temp/git-credentials-22f8368c-3374-4f36-8438-65c6363ee51a.config
includeif.gitdir:/home/runner/work/nitrocop/nitrocop/.git/modules/vendor/rubocop-performance.path
includeif.gitdir:/github/workspace/.git/modules/vendor/rubocop-performance.path
/home/runner/work/_temp/git-credentials-22f8368c-3374-4f36-8438-65c6363ee51a.config
/github/runner_temp/git-credentials-22f8368c-3374-4f36-8438-65c6363ee51a.config
includeif.gitdir:/home/runner/work/nitrocop/nitrocop/.git/modules/vendor/rubocop-rails.path
includeif.gitdir:/github/workspace/.git/modules/vendor/rubocop-rails.path
/home/runner/work/_temp/git-credentials-22f8368c-3374-4f36-8438-65c6363ee51a.config
/github/runner_temp/git-credentials-22f8368c-3374-4f36-8438-65c6363ee51a.config
includeif.gitdir:/home/runner/work/nitrocop/nitrocop/.git/modules/vendor/rubocop-rspec.path
includeif.gitdir:/github/workspace/.git/modules/vendor/rubocop-rspec.path
/home/runner/work/_temp/git-credentials-22f8368c-3374-4f36-8438-65c6363ee51a.config
/github/runner_temp/git-credentials-22f8368c-3374-4f36-8438-65c6363ee51a.config
includeif.gitdir:/home/runner/work/nitrocop/nitrocop/.git/modules/vendor/rubocop-rspec_rails.path
includeif.gitdir:/github/workspace/.git/modules/vendor/rubocop-rspec_rails.path
/home/runner/work/_temp/git-credentials-22f8368c-3374-4f36-8438-65c6363ee51a.config
/github/runner_temp/git-credentials-22f8368c-3374-4f36-8438-65c6363ee51a.config
Removing credentials config '/home/runner/work/_temp/git-credentials-22f8368c-3374-4f36-8438-65c6363ee51a.config'

cop-check-gate

• Route: hard
• Failed steps: Gate check

... (truncated, showing last 80 lines) ...
digest-mismatch: error
##[endgroup]
Found 9 artifact(s)
Filtering artifacts by pattern 'cop-check-summary-*'
Preparing to download the following artifacts:
- cop-check-summary-5 (ID: 6116277990, Size: 160, Expected Digest: sha256:897f6768a2483fefa5a55d5fcf7b59de3f8360dc446db299905a71dad8504e70)
- cop-check-summary-2 (ID: 6116275323, Size: 160, Expected Digest: sha256:b1f71fce5cb53b45239c878eb58358a497a1aca7a7fcaf136763a8132de0ba6b)
- cop-check-summary-6 (ID: 6116275172, Size: 160, Expected Digest: sha256:308cba2891df2de23035abfb95f5d4aa996c7cae23940db33243055248a62bd9)
- cop-check-summary-4 (ID: 6116273645, Size: 160, Expected Digest: sha256:1cce81865c24b6a9bd756903b5dba7947d36caab6064ee925aaf76da0d993724)
- cop-check-summary-1 (ID: 6116271396, Size: 160, Expected Digest: sha256:b12143688e54c2a24baa17a0fdfbfa9dcadff36719bee71a4cc0685f3f0b643d)
- cop-check-summary-0 (ID: 6116270724, Size: 160, Expected Digest: sha256:10ce624328d328e0f0facae286dd3a881408e8a5e61840d3c2bf8d90a5241ade)
- cop-check-summary-3 (ID: 6116270710, Size: 162, Expected Digest: sha256:0d019a7a97a6f1fa013562f3603f726e86ef17732c693bd1e79fcf6a5d91c25a)
- cop-check-summary-7 (ID: 6116270371, Size: 160, Expected Digest: sha256:d6f5ea98980eff99b23c5e8fe642d87afbb937d99d099ba96c2bcbe035f0a917)
Redirecting to blob download url: https://productionresultssa14.blob.core.windows.net/actions-results/5b337e16-f237-4b73-9056-f1b01710c434/workflow-job-run-30d1f678-eb6e-5cbe-830c-6d9dc75cc5aa/artifacts/dbe06f7d99e41d620e76d8482a41caf08d85722d310e3463e4bd345990f450fb.zip
Starting download of artifact to: /home/runner/work/nitrocop/nitrocop/summaries
Redirecting to blob download url: https://productionresultssa14.blob.core.windows.net/actions-results/5b337e16-f237-4b73-9056-f1b01710c434/workflow-job-run-66fb669d-b311-556d-b238-3c76011f2e71/artifacts/d858fb72e456cb26c81cee0096ffc4ffa1046123dc84f53e0ea303f38b08e2ae.zip
Starting download of artifact to: /home/runner/work/nitrocop/nitrocop/summaries
Redirecting to blob download url: https://productionresultssa14.blob.core.windows.net/actions-results/5b337e16-f237-4b73-9056-f1b01710c434/workflow-job-run-5a23c026-2b23-5fe3-96d7-792d839cdc6d/artifacts/841f469bf4187bf41e00294b730cef75cfe282163eeaa718f11794cb19fd653b.zip
Starting download of artifact to: /home/runner/work/nitrocop/nitrocop/summaries
Redirecting to blob download url: https://productionresultssa14.blob.core.windows.net/actions-results/5b337e16-f237-4b73-9056-f1b01710c434/workflow-job-run-5b39c5f7-5d29-54a0-8628-cdde6fd3cdd8/artifacts/935195f8f0e71016eda2bd78755ef915343f9971432e277e50147d73e35e0b6f.zip
Starting download of artifact to: /home/runner/work/nitrocop/nitrocop/summaries
Redirecting to blob download url: https://productionresultssa14.blob.core.windows.net/actions-results/5b337e16-f237-4b73-9056-f1b01710c434/workflow-job-run-0e788646-3293-5fe1-89a2-453102dffc5c/artifacts/6af06aa7f7c22c2c974d6abf9e96c17282a3918e72f4f54e955848833dee4615.zip
Starting download of artifact to: /home/runner/work/nitrocop/nitrocop/summaries
Redirecting to blob download url: https://productionresultssa14.blob.core.windows.net/actions-results/5b337e16-f237-4b73-9056-f1b01710c434/workflow-job-run-8fb1ba6f-2120-5f0a-b251-e28b373c2ed7/artifacts/506a755abd4abce410989dff67bb1c090ccb40fcb62bd84cc96f897572f54763.zip
Starting download of artifact to: /home/runner/work/nitrocop/nitrocop/summaries
(node:2170) [DEP0005] DeprecationWarning: Buffer() is deprecated due to security and usability issues. Please use the Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods instead.
(Use `node --trace-deprecation ...` to show where the warning was created)
SHA256 digest of downloaded artifact is 1cce81865c24b6a9bd756903b5dba7947d36caab6064ee925aaf76da0d993724
Artifact download completed successfully.
SHA256 digest of downloaded artifact is 897f6768a2483fefa5a55d5fcf7b59de3f8360dc446db299905a71dad8504e70
Artifact download completed successfully.
SHA256 digest of downloaded artifact is b12143688e54c2a24baa17a0fdfbfa9dcadff36719bee71a4cc0685f3f0b643d
Artifact download completed successfully.
SHA256 digest of downloaded artifact is d6f5ea98980eff99b23c5e8fe642d87afbb937d99d099ba96c2bcbe035f0a917
Artifact download completed successfully.
SHA256 digest of downloaded artifact is 0d019a7a97a6f1fa013562f3603f726e86ef17732c693bd1e79fcf6a5d91c25a
Artifact download completed successfully.
SHA256 digest of downloaded artifact is 10ce624328d328e0f0facae286dd3a881408e8a5e61840d3c2bf8d90a5241ade
Artifact download completed successfully.
Redirecting to blob download url: https://productionresultssa14.blob.core.windows.net/actions-results/5b337e16-f237-4b73-9056-f1b01710c434/workflow-job-run-39445903-52fd-5eab-a8d9-00d5cf9726e2/artifacts/20ac3cf8f9ac90a8982305e209367a442ffb3d698222db2dfe1e6f3c065d106a.zip
Starting download of artifact to: /home/runner/work/nitrocop/nitrocop/summaries
Redirecting to blob download url: https://productionresultssa14.blob.core.windows.net/actions-results/5b337e16-f237-4b73-9056-f1b01710c434/workflow-job-run-80f7b1b6-fbd3-5745-80f9-34e1cea996b1/artifacts/4cfbe6a2adc1aa6e06bb17b3cc1c859241338f4e3dee33920e5e60a97299bc2b.zip
Starting download of artifact to: /home/runner/work/nitrocop/nitrocop/summaries
SHA256 digest of downloaded artifact is 308cba2891df2de23035abfb95f5d4aa996c7cae23940db33243055248a62bd9
Artifact download completed successfully.
SHA256 digest of downloaded artifact is b1f71fce5cb53b45239c878eb58358a497a1aca7a7fcaf136763a8132de0ba6b
Artifact download completed successfully.
Total of 8 artifact(s) downloaded
Download artifact has finished successfully
##[group]Run RESULT="fail"
RESULT="fail"
ICON="✅"
[ "$RESULT" = "fail" ] && ICON="❌"
BODY="${ICON} **Cop-check results** (8 shards)\n\n"
BODY+="| Cop | Baseline FP | Baseline FN | New FP | New FN | Result |\n"
BODY+="|-----|-----------|-----------|--------|--------|--------|\n"
if [ -d summaries ]; then
for f in summaries/*.txt; do
[ -f "$f" ] || continue
while IFS='|' read -r cop bl_fp bl_fn new_fp new_fn shard_result; do
STATUS="✅"
[ "$shard_result" = "fail" ] && STATUS="❌"
BODY+="| \`${cop}\` | ${bl_fp} | ${bl_fn} | ${new_fp} | ${new_fn} | ${STATUS} |\n"
done < "$f"
done
else
BODY+="| (no shard data) | | | | | ${RESULT} |\n"
fi
if [ "$RESULT" = "pass" ]; then
BODY+="\nAll shards passed — ready to merge.\n"
else
BODY+="\nRegressions detected. The repair workflow will attempt an automatic fix.\n"
fi
printf "$BODY" | gh pr comment "202" \
--repo "6/nitrocop" --body-file -
shell: /usr/bin/bash -e {0}
env:
GH_TOKEN: ***
##[endgroup]
https://github.com/6/nitrocop/pull/202#issuecomment-4131554400

Constraints

• Keep the fix scoped to the failing checks.
• Reuse the existing PR branch and existing tests where possible.
• Prefer the minimal patch that makes the deterministic verification pass.
• A full revert to origin/main or an empty PR is treated as a failed repair, not a success.
• If a fix is blocked by missing context, explain that clearly in the final message.

Available Local Helper Scripts

These helper scripts are available in this CI checkout. Prefer the stable top-level CLI paths shown below over ad hoc commands when they directly help with diagnosis or validation.

• scripts/check_cop.py — aggregate corpus regression check for one cop
• scripts/dispatch_cops.py — dispatch helpers for changed cops, task generation, ranking, and prior attempts
• scripts/investigate_cop.py — inspect FP/FN examples from corpus oracle data
• scripts/verify_cop_locations.py — verify exact known oracle FP/FN locations
• scripts/corpus_smoke_test.py — smoke-test a few pinned repos

Typical usage when present:

python3 scripts/check_cop.py Department/CopName --verbose --rerun --clone
python3 scripts/dispatch_cops.py changed --base origin/main --head HEAD
python3 scripts/investigate_cop.py Department/CopName --context
python3 scripts/verify_cop_locations.py Department/CopName
python3 scripts/corpus_smoke_test.py --binary target/release/nitrocop

Local Cop-Check Diagnosis

The workflow already reran the changed-cop corpus check locally before agent execution.
Use this packet as the starting point instead of rediscovering the same corpus regression.

Changed cops:

• Rails/Delegate

Rails/Delegate

Start here:

• Re-run after edits: python3 scripts/check_cop.py Rails/Delegate --verbose --rerun --clone
• Baseline corpus context: python3 scripts/investigate_cop.py Rails/Delegate --input /home/runner/work/_temp/agent-pr-repair/repair/corpus.json --repos-only
• Inspect repo: /home/runner/work/nitrocop/nitrocop/vendor/corpus/liaoziyang__stackneveroverflow__8f4dce2
• Inspect repo: /home/runner/work/nitrocop/nitrocop/vendor/corpus/databasically__lowdown__d593927
• Inspect repo: /home/runner/work/nitrocop/nitrocop/vendor/corpus/cjstewart88__Tubalr__f6956c8
• Inspect repo: /home/runner/work/nitrocop/nitrocop/vendor/corpus/pitluga__supply_drop__d64c50c
• Inspect repo: /home/runner/work/nitrocop/nitrocop/vendor/corpus/rabbit-shocker__rabbit__c5f17ea

Oracle context from CI corpus artifact:

• Repos and exact examples: python3 scripts/investigate_cop.py Rails/Delegate --input /home/runner/work/_temp/agent-pr-repair/repair/corpus.json --fn-only --context --limit 10
  Oracle FN hotspots:
• cjstewart88__Tubalr__f6956c8 (30 FN)
• liaoziyang__stackneveroverflow__8f4dce2 (21 FN)
• pitluga__supply_drop__d64c50c (14 FN)
  Oracle FP hotspots:
• cjstewart88__Tubalr__f6956c8 (1 FP)
• travis-ci__travis-api__d1cbb6d (1 FP)
• travis-ci__travis-yaml__5b5fe81 (1 FP)

Representative oracle FN examples:

• cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb:594 — Use delegate to define delegations.

      587:   end
      588: 
      589:   ##
      590:   # Add to the sequences used to add formatting to an individual word (such
      591:   # as *bold*).  Matching entries will generate attributes that the output
      592:   # formatters can recognize by their +name+.
      593: 
>>>   594:   def add_word_pair(start, stop, name)

• cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb:601 — Use delegate to define delegations.

      594:   def add_word_pair(start, stop, name)
      595:     @attribute_manager.add_word_pair(start, stop, name)
      596:   end
      597: 
      598:   ##
      599:   # Add to the sequences recognized as general markup.
      600: 
>>>   601:   def add_html(tag, name)

• cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rdoc-3.8/lib/rdoc/markup.rb:614 — Use delegate to define delegations.

      607:   # something like:
      608:   #
      609:   #    parser.add_special(/\b([A-Z][a-z]+[A-Z]\w+)/, :WIKIWORD)
      610:   #
      611:   # Each wiki word will be presented to the output formatter via the
      612:   # accept_special method.
      613: 
>>>   614:   def add_special(pattern, name)

Representative oracle FP examples:

• cjstewart88__Tubalr__f6956c8: heroku/ruby/1.9.1/gems/rack-1.2.3/lib/rack/utils.rb:461 — Use delegate to define delegations.

      454:           @original_filename = ::File.basename(path)
      455:           @tempfile = Tempfile.new(@original_filename)
      456:           @tempfile.set_encoding(Encoding::BINARY) if @tempfile.respond_to?(:set_encoding)
      457:           @tempfile.binmode if binary
      458:           FileUtils.copy_file(path, @tempfile.path)
      459:         end
      460: 
>>>   461:         def path

• travis-ci__travis-api__d1cbb6d: lib/travis/api/v3/queries/account_env_var.rb:13 — Use delegate to define delegations.

/usr/bin/python3 scripts/check_cop.py Rails/Delegate --verbose --rerun --clone --sample 15

Exit status: 1

Checking Rails/Delegate against corpus
Gate: count-only cop-level regression check
Not a location-level conformance proof or a department completion gate
Baseline (from CI): 23,053 matches, 3 FP, 78 FN
Expected RuboCop offenses: 23,131

Repos with offenses (15):
     461  liaoziyang__stackneveroverflow__8f4dce2
     250  databasically__lowdown__d593927
     239  cjstewart88__Tubalr__f6956c8
      81  pitluga__supply_drop__d64c50c
      31  rabbit-shocker__rabbit__c5f17ea
      20  travis-ci__travis-api__d1cbb6d
      19  dmayer__idb__0383554
      17  kristianmandrup__cantango__1920ea6
      13  enspirit__finitio-rb__32633a8
       9  pannous__english-script__7707e75
       9  travis-ci__travis-yaml__5b5fe81
       8  appoxy__aws__bd57c8f
       7  amuta__kumi__790c2e0
       3  rails__thor__6a680f2
       1  lucascaton__enumerate_it__6994e78

Results:
  Expected (RuboCop):       23,131
  Actual (nitrocop):         1,168
  CI nitrocop baseline:     23,056
  Excess (potential FP):         0
  Missing (potential FN):   21,963

  Gate type: count-only / cop-level regression

  Gate: per-repo regression vs oracle baseline
  New FP (worse than baseline):      0
  New FN (worse than baseline):      5

FAIL: FN regression detected (+5)
  +   5  liaoziyang__stackneveroverflow__8f4dce2  (local=461, baseline_nc=466, rubocop=487)
SUMMARY|Rails/Delegate|1|0|0|5|fail
gh CLI found but not authenticated, trying other methods...
Using cached corpus-results from run 23555948554
  --sample: 15/2111 repos (8 diverging + 7 by offense count)
  Cloning 15 repos for Rails/Delegate into /tmp/nitrocop_cop_check_mi56j53e...
  Cloning 15 repos...
  Cloned 15/15 repos
Running nitrocop per-repo...
  --sample: 15/2111 repos (8 diverging + 7 by offense count)
  --quick: running 15/15 repos (skipping 0 with zero baseline activity)
Debug: per-repo counts written to /home/runner/work/nitrocop/nitrocop/check-cop-debug.json
Per-repo discrepancy analysis:
  check-cop total: 1168, oracle expected: 23131, diff: -21963
  Repos in oracle activity but 0 locally (2096):
    24pullrequests__24pullrequests__381028d
    7even__vkontakte_api__daa4a91
    AaronC81__parlour__ffc0e09
    AaronC81__sord__8713f8a
    AaronLasseigne__active_interaction__97667c8
    ActiveCampaign__postmark-gem__a50ff39
    ActiveCampaign__postmark-rails__f9e4acc
    Albacore__albacore__e316e20
    AlchemyCMS__alchemy_cms__4c2023f
    AlexB52__retest__548f9d2

[6]

Auto-repair Agent Failed

• Checks run: #23577205827
• Backend: codex / hard
• Repair workflow: #23595811949

The repair agent step failed before local verification ran.

[6]

✅ Cop-check results (8 shards)

Cop	Baseline FP	Baseline FN	New FP	New FN	Result
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	0	✅
Rails/Delegate	0	0	0	0	✅

All shards passed — ready to merge.

[6]

Investigation is correct: remaining FN are file-discovery/config scoping, not matcher bugs. Good fixture coverage for real corpus patterns. Doc comment will prevent repeat investigations.