Module: Evilution::Feedback::SetupWarning Private

Defined in:

lib/evilution/feedback/setup_warning.rb

Overview

This module is part of a private API. You should avoid using this module if possible, as it may be removed or be changed in the future.

Detects "setup misconfiguration" patterns where mutation testing returned a result that is technically valid (score 0.0 with all-errored mutations) but is almost certainly the wrong score because the worker process couldn't evaluate any mutated source.

Most common cause: MCP runs default to preload: false to keep the long-lived MCP server clean. Rails / Zeitwerk projects that depend on autoload then fail in every worker with NameError: uninitialized constant .... The user sees "0% PASS-but-FAIL" with no obvious hint that they need to pass an explicit preload: spec/rails_helper.rb option.

When triggered, this returns a warning string the MCP response can surface alongside the trimmed report — turning a silent wrong score into a loud pointer at the likely fix.

Constant Summary

ERROR_DOMINANCE_THRESHOLD =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future.

0.8

ERROR_CLASS_CLUSTER_THRESHOLD =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future.

0.8

NAME_ERROR_HINT =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future.

"Most mutations errored with NameError. This usually means autoloaded constants " \
"(Rails / Zeitwerk) weren't available when the mutation re-evaluated the source. " \
"Pass `preload: 'spec/rails_helper.rb'` (or your project's preload entry) so the " \
"MCP server requires it before forking workers."

LOAD_ERROR_HINT =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future.

"Most mutations errored with LoadError. A `require` in the mutated source path " \
"failed before any test ran. Check that the file's dependencies are reachable from " \
"the MCP server's load path, or pass `preload: '<entrypoint>'` to set them up."

GENERIC_HINT_TEMPLATE =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future.

"Most mutations errored with %<klass>s (%<count>d / %<total>d). The mutation " \
"score reflects this setup failure, not the test suite. Try the CLI for an " \
"independent reading, or pass `preload: '<path>'` if the failure is autoload-related."

Class Method Summary

• .call(summary) ⇒ Object private

Class Method Details

.call(summary) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

# File 'lib/evilution/feedback/setup_warning.rb', line 25

def call(summary)
  return nil if summary.nil?
  return nil unless errors_dominate?(summary)

  errored = summary.results.select(&:error?)
  dominant_class = dominant_error_class(errored)
  return nil unless dominant_class

  message_for(dominant_class, errored.size, summary.total)
end