Repository Analysis

catchorg/Catch2

A modern, C++-native, test framework for unit-tests, TDD and BDD - using C++14, C++17 and later (C++11 support is in v2.x branch, and C++03 on the Catch1.x branch)

2.4 Likely human-written View on GitHub

Analysis Overview

This report presents the forensic synthetic code analysis of catchorg/Catch2, a C++ project with 21,290 GitHub stars. SynthScan v2.0 examined 207,918 lines of code across 540 source files, recording 541 pattern matches distributed across 10 syntactic categories. The overall adjusted score of 2.4 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).

2.4
Adjusted Score
2.4
Raw Score
100%
Time Factor
2026-07-10
Last Push
21.3K
Stars
C++
Language
207.9K
Lines of Code
540
Files
541
Pattern Hits
2026-07-14
Scan Date
0.01
HC Hit Rate

What These Metrics Mean

Adjusted Score
Primary synthetic code indicator. Raw score normalised per 1,000 lines of code and multiplied by the temporal discount factor. This is the definitive comparative metric — use it to rank repositories by AI authorship density.
Raw Score
The unmodified sum of all severity-weighted, context-multiplied pattern match scores before temporal discounting. Reflects the absolute signal strength independent of when the repository was last active.
Time Factor
The temporal discount multiplier (0–100%) applied to the raw score. Repositories last updated before ChatGPT's launch (Nov 2022) receive a 5% factor. Full signal is only assigned to repositories active in the post-adoption era (Jan 2024+).
Pattern Hits
Total count of individual pattern matches across all files and categories. A high hit count with a low score may indicate a very large codebase with isolated AI snippets; a low count with a high score indicates dense, concentrated AI signatures.
HC Hit Rate
High+Critical pattern hits per file, averaged across the repository. This orthogonal signal catches repositories where a few files are densely packed with high-severity AI tells — a strong indicator even when the normalised score appears moderate due to codebase size.
Lines of Code / Files
Total lines and files analysed. The scanner examines 94 file extensions. These denominators are used to normalise the score, enabling fair comparison between repositories of vastly different sizes.

Score History

This chart maps the temporal evolution of the adjusted synthetic code score across successive scan runs. An upward trajectory indicates ongoing incorporation of AI-generated code or expanding LLM-assisted scaffolding; a stable or declining trajectory may reflect active human refactoring, code removal, or the adoption of stricter authorship policies. The dashed secondary line (right axis) independently tracks total raw pattern hit count, which can diverge from the normalised score when codebase size changes significantly between scans.

Severity Breakdown

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.

CRITICAL 0HIGH 4MEDIUM 4LOW 533

Directory Score Breakdown

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.

Pattern Findings

The scanner identified 541 distinct pattern matches across 10 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.

Over-Commented Block506 hits · 440 pts
SeverityFileLineSnippetContext
LOWtools/scripts/extractFeaturesFromReleaseNotes.py1#!/usr/bin/env python3COMMENT
LOWtools/scripts/updateDocumentSnippets.py1#!/usr/bin/env python3COMMENT
LOWtools/scripts/updateDocumentToC.py1#!/usr/bin/env python3COMMENT
LOWfuzzing/fuzz_textflow.cpp1COMMENT
LOWtests/SelfTest/TestRegistrations.cpp1COMMENT
LOWtests/SelfTest/IntrospectiveTests/ToString.tests.cpp1COMMENT
LOW…elfTest/IntrospectiveTests/InternalBenchmark.tests.cpp1COMMENT
LOWtests/SelfTest/IntrospectiveTests/Json.tests.cpp1COMMENT
LOW…s/SelfTest/IntrospectiveTests/GeneratorsImpl.tests.cpp1COMMENT
LOWtests/SelfTest/IntrospectiveTests/Details.tests.cpp1COMMENT
LOWtests/SelfTest/IntrospectiveTests/Reporters.tests.cpp1COMMENT
LOWtests/SelfTest/IntrospectiveTests/CmdLine.tests.cpp1COMMENT
LOWtests/SelfTest/IntrospectiveTests/TestSpec.tests.cpp1COMMENT
LOW…st/IntrospectiveTests/RandomNumberGeneration.tests.cpp1COMMENT
LOWtests/SelfTest/IntrospectiveTests/Integer.tests.cpp21 CHECK( extendedMult( b, a ) ==COMMENT
LOWtests/SelfTest/IntrospectiveTests/Xml.tests.cpp1COMMENT
LOWtests/SelfTest/UsageTests/Exception.tests.cpp1COMMENT
LOWtests/SelfTest/UsageTests/Exception.tests.cpp201COMMENT
LOWtests/SelfTest/UsageTests/ToStringVariant.tests.cpp1COMMENT
LOWtests/SelfTest/UsageTests/Generators.tests.cpp1COMMENT
LOWtests/SelfTest/UsageTests/Generators.tests.cpp41 REQUIRE(x < z);COMMENT
LOWtests/SelfTest/UsageTests/Misc.tests.cpp1COMMENT
LOWtests/SelfTest/UsageTests/Message.tests.cpp241 return out;COMMENT
LOWtests/SelfTest/UsageTests/Message.tests.cpp281COMMENT
LOWtests/SelfTest/UsageTests/Compilation.tests.cpp1COMMENT
LOWtests/SelfTest/UsageTests/Compilation.tests.cpp81COMMENT
LOWtests/SelfTest/UsageTests/MatchersConstexpr.tests.cpp1COMMENT
LOWtests/SelfTest/UsageTests/MatchersRanges.tests.cpp1COMMENT
LOWtests/SelfTest/UsageTests/Tricky.tests.cpp1COMMENT
LOWtests/SelfTest/UsageTests/Benchmark.tests.cpp1COMMENT
LOWtests/SelfTest/UsageTests/ToStringWhich.tests.cpp1COMMENT
LOWtests/SelfTest/UsageTests/Matchers.tests.cpp1COMMENT
LOWtests/SelfTest/UsageTests/Condition.tests.cpp1COMMENT
LOWtests/SelfTest/UsageTests/Class.tests.cpp1COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt1##teamcity[testSuiteStarted name='<exe-name>']COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt21##teamcity[testFailed name='#1514: stderr/stdout is not captured in tests aborted by an exception' message='Tricky.testsCOMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt41##teamcity[testStarted name='#1938 - mixed sections and generates']COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt61##teamcity[testIgnored name='#748 - captures with unexpected exceptions' message='--------------------------------------COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt81##teamcity[testFailed name='|'Not|' checks that should fail' message='Condition.tests.cpp:<line number>|nexpression failCOMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt101##teamcity[testFinished name='A TEMPLATE_PRODUCT_TEST_CASE_METHOD based test run that fails - Template_Foo<int>' duratioCOMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt121##teamcity[testFinished name='A TEMPLATE_PRODUCT_TEST_CASE_METHOD_SIG based test run that fails - Template_Foo_2<int, 2>COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt141##teamcity[testFinished name='A TEMPLATE_TEST_CASE_METHOD based test run that fails - float' duration="{duration}"]COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt161##teamcity[testFinished name='A TEMPLATE_TEST_CASE_METHOD_SIG based test run that succeeds - 1' duration="{duration}"]COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt181##teamcity[testFinished name='A Template product test case - std::vector<float>' duration="{duration}"]COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt201##teamcity[testStarted name='Absolute margin']COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt221##teamcity[testFinished name='Approximate comparisons with floats' duration="{duration}"]COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt241##teamcity[testFinished name='Basic use of the Contains range matcher' duration="{duration}"]COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt261##teamcity[testFinished name='CaseInsensitiveLess is case insensitive' duration="{duration}"]COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt281##teamcity[testFinished name='Combining only templated matchers' duration="{duration}"]COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt301##teamcity[testFinished name='Comparisons with int literals don|'t warn when mixing signed/ unsigned' duration="{duratioCOMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt321##teamcity[testFinished name='Custom exceptions can be translated when testing for throwing as something else' duration=COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt341##teamcity[testStarted name='Enum backed by larger underlying type']COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt361##teamcity[testIgnored name='Equality checks that should fail' message='Condition.tests.cpp:<line number>|nexpression faCOMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt381##teamcity[testFinished name='Exception matchers that fail' duration="{duration}"]COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt401##teamcity[testIgnored name='FAIL can be nested in assertion' message='AssertionHandler.tests.cpp:<line number>|n.......COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt421##teamcity[testFinished name='GENERATE can combine literals and generators' duration="{duration}"]COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt441##teamcity[testFinished name='Hashing test case produces same hash across multiple calls' duration="{duration}"]COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt461##teamcity[testIgnored name='Inequality checks that should fail' message='Condition.tests.cpp:<line number>|n...........COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt481##teamcity[testStarted name='MapGenerator can handle not default constructible types']COMMENT
LOWtests/SelfTest/Baselines/teamcity.sw.approved.txt501##teamcity[testIgnored name='Mayfail test case with nested sections' message='------------------------------------------COMMENT
446 more matches not shown…
Cross-File Repetition4 hits · 20 pts
SeverityFileLineSnippetContext
HIGHtests/TestScripts/testConfigureExperimentalRedirect.py0tests the cmake configure option for catch_config_disable_stringification requires 2 arguments, path folder where the caSTRING
HIGHtests/TestScripts/testConfigureDisable.py0tests the cmake configure option for catch_config_disable_stringification requires 2 arguments, path folder where the caSTRING
HIGHtests/TestScripts/testConfigureDefaultReporter.py0tests the cmake configure option for catch_config_disable_stringification requires 2 arguments, path folder where the caSTRING
HIGH…sts/TestScripts/testConfigureDisableStringification.py0tests the cmake configure option for catch_config_disable_stringification requires 2 arguments, path folder where the caSTRING
Unused Imports11 hits · 11 pts
SeverityFileLineSnippetContext
LOWtools/scripts/approve.py5CODE
LOWtools/scripts/releaseCommon.py3CODE
LOWtools/scripts/approvalTests.py11CODE
LOWtools/scripts/checkConvenienceHeaders.py19CODE
LOWtools/scripts/updateDocumentToC.py17CODE
LOWtests/TestScripts/testSharding.py23CODE
LOWtests/TestScripts/testConfigureExperimentalRedirect.py13CODE
LOWtests/TestScripts/testConfigureDisable.py13CODE
LOWtests/TestScripts/testBazelSharding.py11CODE
LOWtests/TestScripts/testConfigureDefaultReporter.py13CODE
LOW…sts/TestScripts/testConfigureDisableStringification.py13CODE
Decorative Section Separators2 hits · 6 pts
SeverityFileLineSnippetContext
MEDIUMtools/scripts/updateDocumentSnippets.py7# ---------------------------------------------------COMMENT
MEDIUMtools/scripts/updateDocumentSnippets.py9# ---------------------------------------------------COMMENT
Fake / Example Data4 hits · 6 pts
SeverityFileLineSnippetContext
LOWtests/SelfTest/IntrospectiveTests/TextFlow.tests.cpp188 "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque nisl \n"CODE
LOWtests/SelfTest/IntrospectiveTests/TextFlow.tests.cpp188 "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque nisl \n"CODE
LOWtests/SelfTest/IntrospectiveTests/TextFlow.tests.cpp197 " Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque nisl \n"CODE
LOWtests/SelfTest/IntrospectiveTests/TextFlow.tests.cpp197 " Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque nisl \n"CODE
Hyper-Verbose Identifiers5 hits · 5 pts
SeverityFileLineSnippetContext
LOWconanfile.py38 def _compilers_minimum_version(self):CODE
LOWtools/scripts/extractFeaturesFromReleaseNotes.py27def create_introduced_in_text(version, bug_number = None):CODE
LOWtools/scripts/extractFeaturesFromReleaseNotes.py36def link_to_changes_in_release(release, releases):CODE
LOWtools/scripts/extractFeaturesFromReleaseNotes.py54def write_recent_release_notes_with_introduced_text():CODE
LOWtools/scripts/checkConvenienceHeaders.py76def verify_convenience_header(folder):CODE
Excessive Try-Catch Wrapping3 hits · 5 pts
SeverityFileLineSnippetContext
LOWtests/TestScripts/testBazelExitGuardFile.py86 except Exception as ex:CODE
MEDIUMtests/TestScripts/DiscoverTests/VerifyRegistration.py59 print('Error when building the test project')CODE
MEDIUMtests/TestScripts/DiscoverTests/VerifyRegistration.py111 print('Error when getting output from CTest')CODE
Deep Nesting3 hits · 3 pts
SeverityFileLineSnippetContext
LOWtools/scripts/extractFeaturesFromReleaseNotes.py54CODE
LOWtools/scripts/fixWhitespace.py9CODE
LOWtools/scripts/updateDocumentToC.py109CODE
Verbosity Indicators2 hits · 3 pts
SeverityFileLineSnippetContext
LOWsrc/catch2/internal/catch_run_context.cpp153 // No children have started. We need to check if theyCOMMENT
LOWextras/catch_amalgamated.cpp5973 // No children have started. We need to check if theyCOMMENT
AI Structural Patterns1 hit · 1 pts
SeverityFileLineSnippetContext
LOWtools/scripts/updateDocumentToC.py268CODE