Code coverage for Ruby with a powerful configuration library and automatic merging of coverage across test suites
This report presents the forensic synthetic code analysis of simplecov-ruby/simplecov, a Ruby project with 4,910 GitHub stars. SynthScan v2.0 examined 28,525 lines of code across 294 source files, recording 107 pattern matches distributed across 6 syntactic categories. The overall adjusted score of 4.3 places this repository in the Likely human-written band.
The scanner applied 160+ deterministic lexical heuristics, multi-line block detectors, abstract syntax tree depth profilers, and a cross-file Jaccard similarity matrix to construct a statistically normalised synthetic code estimate. All matches are individually weighted by severity coefficient and contextual multiplier before summation, and the resulting headline score is temporally discounted to account for the repository's development history relative to the commercial emergence of large language model coding tooling (November 2022 onward).
Longitudinal tracking requires multiple scan runs. Once this repository is re-scanned after new commits land, this chart will visualise how the synthetic code signal evolves over time — enabling you to detect whether AI authorship is growing, stabilising, or being actively corrected by human engineers.
Classifies detected patterns by their diagnostic confidence and structural impact. CRITICAL patterns (coefficient 10) represent definitive synthetic signatures — hallucinated imports, explicit LLM attribution metadata — virtually never produced by human authors. HIGH (5) indicates strong structural tells such as cross-file repetition or cross-linguistic idioms. MEDIUM (2) covers recognisable conversational padding and AI-specific vocabulary. LOW (1) captures subtle indicators like tautological comments and generic boilerplate that require density to carry independent signal.
This horizontal bar chart decomposes the repository's raw synthetic code score by top-level directory, allowing you to pinpoint precisely which modules or components carry the highest AI authorship density. Directories with disproportionately high scores relative to their size warrant targeted manual review: concentrated AI signatures often trace back to mass-generated configuration layers, auto-ported test suites, LLM-scaffolded boilerplate classes, or entire subsystems authored under heavy copilot assistance. Use this view to prioritise your human code-review effort.
The scanner identified 107 distinct pattern matches across 6 syntactic categories. Each entry below represents a discrete location in the source code where the engine recorded a statistically significant AI authorship indicator. Expand any category row to inspect the individual file paths, line numbers, code snippets, and the lexical context (CODE, COMMENT, or STRING) in which each match was detected.
Reading the findings table: The Severity column indicates the diagnostic confidence level (CRITICAL / HIGH / MEDIUM / LOW). The Context column identifies whether the match occurred inside executable code, an inline comment, or a string literal — comment-context matches receive a ×1.5 weight because LLMs systematically over-annotate. The ⚡ bolt icon marks clustered matches: three or more patterns within a 10-line window, each receiving an additional ×1.5 density multiplier as dense clusters constitute far stronger evidence of synthetic authorship than isolated hits.
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | spec/simplecov_spec.rb | 1101 | end | COMMENT |
| LOW | spec/helper.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | spec/helper.rb | 41 | # asserts the same warning (the suite runs in random order). | COMMENT |
| LOW | spec/helper.rb | 61 | # the dogfood `Result.new`, not into `SimpleCov.filters`, so they | COMMENT |
| LOW | spec/helper.rb | 101 | # formatter's `warn`-based status line and any threshold-violation | COMMENT |
| LOW | spec/static_coverage_extractor_spec.rb | 141 | # Coverage doesn't emit a branch entry for `||=`, neither do we. | COMMENT |
| LOW | spec/support/with_env.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov.rb | 21 | COMMENT | |
| LOW | lib/simplecov.rb | 81 | # SimpleCov.start 'rails' # using a profile | COMMENT |
| LOW | lib/simplecov.rb | 121 | COMMENT | |
| LOW | lib/simplecov/profiles.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/profiles.rb | 21 | COMMENT | |
| LOW | lib/simplecov/parallel_coordination.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/parallel_coordination.rb | 61 | # | COMMENT |
| LOW | lib/simplecov/result_processing.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/directive.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/directive.rb | 21 | # | COMMENT |
| LOW | lib/simplecov/filter.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/process.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/parallel_adapters.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/parallel_adapters.rb | 21 | # - `GenericAdapter` — env-var-only detection for runners that follow | COMMENT |
| LOW | lib/simplecov/parallel_adapters.rb | 41 | # are prepended (#register puts new entries at the front) so | COMMENT |
| LOW | lib/simplecov/result_adapter.rb | 41 | # from different processes can be merged. Anonymous class names like | COMMENT |
| LOW | lib/simplecov/load_global_config.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/autostart.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/coverage_statistics.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/simulate_coverage.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/simulate_coverage.rb | 21 | # know about. This keeps "relevant lines" identical whether a file was | COMMENT |
| LOW | lib/simplecov/deprecation.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/static_coverage_extractor.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/static_coverage_extractor.rb | 21 | # When Prism isn't available, `available?` returns false and SimulateCoverage | COMMENT |
| LOW | lib/simplecov/static_coverage_extractor.rb | 61 | visitor.visit(result.value) | COMMENT |
| LOW | lib/simplecov/static_coverage_extractor.rb | 81 | # | COMMENT |
| LOW | lib/simplecov/color.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/configuration.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/configuration.rb | 41 | # callers can override with an arbitrary absolute path — handy for | COMMENT |
| LOW | lib/simplecov/configuration.rb | 121 | # is actively tracking, or a `@result` has already been assembled | COMMENT |
| LOW | lib/simplecov/configuration/filters.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/configuration/filters.rb | 21 | # | COMMENT |
| LOW | lib/simplecov/configuration/filters.rb | 41 | def cover_filters | COMMENT |
| LOW | lib/simplecov/configuration/merging.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/configuration/coverage.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/configuration/coverage.rb | 21 | # coverage :method, minimum: 100 | COMMENT |
| LOW | lib/simplecov/configuration/formatting.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/configuration/formatting.rb | 41 | # Sets the configured formatters. Equivalent to `formatters [...]`. | COMMENT |
| LOW | lib/simplecov/configuration/formatting.rb | 81 | # downstream tool reads the project's source files directly and | COMMENT |
| LOW | lib/simplecov/combine/results_combiner.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/combine/methods_combiner.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/combine/branches_combiner.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/combine/lines_combiner.rb | 21 | COMMENT | |
| LOW | lib/simplecov/parallel_adapters/base.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/parallel_adapters/base.rb | 21 | false | COMMENT |
| LOW | lib/simplecov/parallel_adapters/generic.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/parallel_adapters/parallel_tests.rb | 21 | ensure_loaded | COMMENT |
| LOW | lib/simplecov/parallel_adapters/parallel_tests.rb | 61 | # for other reasons (custom subprocess coordination, CI sharding, | COMMENT |
| LOW | lib/simplecov/cli/dotfile.rb | 21 | rescue LoadError, StandardError => e | COMMENT |
| LOW | lib/simplecov/cli/diff.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/formatter/base.rb | 1 | # frozen_string_literal: true | COMMENT |
| LOW | lib/simplecov/formatter/base.rb | 61 | end | COMMENT |
| LOW | lib/simplecov/profiles/rails.rb | 21 | # which both injects unloaded files and scopes the report to the match | COMMENT |
| 9 more matches not shown… | ||||
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | spec/return_codes_spec.rb | 25 | def stderr_without_report_summary(stderr) | CODE |
| LOW | spec/support/fail_rspec_on_ruby_warning.rb | 65 | def write_other_warnings_to_tmp(other_warnings) | CODE |
| LOW | lib/simplecov/parallel_coordination.rb | 74 | def wait_for_parallel_results(expected, native_wait: false) | CODE |
| LOW | lib/simplecov/parallel_coordination.rb | 116 | def warn_about_incomplete_parallel_results(expected, seen) | CODE |
| LOW | lib/simplecov/result_adapter.rb | 78 | def adapt_oneshot_lines_if_needed(file_name, cover_statistic) | CODE |
| LOW | lib/simplecov/exit_handling.rb | 98 | def exit_and_report_previous_error(exit_status) | CODE |
| LOW | lib/simplecov/result.rb | 138 | def warn_about_missing_source_files(missing, input_size) | CODE |
| LOW | lib/simplecov/result_merger.rb | 70 | def warn_about_expired_results(expired_command_names) | CODE |
| LOW | lib/simplecov/lines_classifier.rb | 54 | def directive_disabled_line_set(lines) | CODE |
| LOW | lib/simplecov/coverage_violations.rb | 84 | def effective_per_file_thresholds(file, defaults, overrides) | CODE |
| LOW | lib/simplecov/configuration/filters.rb | 70 | def track_files_replacement_hint(glob) | CODE |
| LOW | lib/simplecov/configuration/coverage_criteria.rb | 142 | def raise_if_criterion_disabled(criterion) | CODE |
| LOW | lib/simplecov/configuration/coverage_criteria.rb | 151 | def raise_if_criterion_unsupported(criterion) | CODE |
| LOW | lib/simplecov/configuration/ignored_entries.rb | 47 | def raise_if_branch_type_unsupported(type) | CODE |
| LOW | lib/simplecov/configuration/ignored_entries.rb | 55 | def raise_if_method_type_unsupported(type) | CODE |
| LOW | lib/simplecov/configuration/coverage.rb | 75 | def enable_coverage_criterion(criterion, enabled:, oneshot:) | CODE |
| LOW | lib/simplecov/configuration/thresholds.rb | 22 | def raise_on_invalid_coverage(coverage, coverage_setting) | CODE |
| LOW | lib/simplecov/configuration/thresholds.rb | 98 | def minimum_coverage_by_group(coverage = nil) | CODE |
| LOW | lib/simplecov/configuration/thresholds.rb | 124 | def partition_per_file_thresholds(coverage) | CODE |
| LOW | lib/simplecov/configuration/thresholds.rb | 142 | def minimum_possible_coverage_exceeded(coverage_option) | CODE |
| LOW | lib/simplecov/configuration/thresholds.rb | 149 | def per_file_coverage_replacement(defaults, overrides) | CODE |
| LOW | lib/simplecov/configuration/thresholds.rb | 161 | def per_group_coverage_replacement(coverage) | CODE |
| LOW | lib/simplecov/cli/merge.rb | 88 | def warn_about_duplicate_command_names(parsed, stderr) | CODE |
| LOW | lib/simplecov/formatter/json_formatter.rb | 51 | def warn_if_concurrent_overwrite(path, result) | CODE |
| LOW | …ecov/formatter/json_formatter/result_hash_formatter.rb | 97 | def format_coverage_statistics(statistics) | CODE |
| LOW | lib/simplecov/source_file/ruby_data_parser.rb | 83 | def quote_inspected_class_segments(str) | CODE |
| LOW | lib/simplecov/source_file/source_loader.rb | 44 | def set_encoding_based_on_magic_comment(file, line) | CODE |
| LOW | html_frontend/src/bar_width.ts | 47 | export function scheduleEqualizeBarWidths(): void { | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | lib/simplecov/profiles.rb | 13 | # Define a SimpleCov profile: | COMMENT |
| MEDIUM | lib/simplecov/configuration/filters.rb | 129 | # Define a display group for files. Same matcher grammar as `skip`, | COMMENT |
| MEDIUM | …ils/rspec_rails/config/initializers/wrap_parameters.rb | 3 | # This file contains settings for ActionController::ParamsWrapper which | COMMENT |
| MEDIUM | test_projects/rails/rspec_rails/spec/rails_helper.rb | 1 | # This file is copied to spec/ when you run 'rails generate rspec:install' | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | lib/simplecov/exit_handling.rb | 5 | # `at_exit` orchestration: post-suite report generation, threshold | COMMENT |
| MEDIUM | lib/simplecov/formatter/base.rb | 9 | # Shared scaffolding for formatters that write a coverage report to | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | spec/static_coverage_extractor_spec.rb | 153 | # differential harness that pins them tuple-for-tuple: every | COMMENT |
| LOW | lib/simplecov/profiles/strict.rb | 12 | # accepted (they just add to the configured criteria set), but the | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | lib/simplecov/source_file.rb | 159 | # Check if any branches missing on given line number | COMMENT |
| LOW | lib/simplecov/source_file/branch.rb | 34 | # Check if branch missed or not | COMMENT |