Repository Analysis

chaijs/chai

BDD / TDD assertion framework for node.js and the browser that can be paired with any testing framework.

47.2 Strong AI signal View on GitHub

Analysis Overview

This report presents the forensic synthetic code analysis of chaijs/chai, a JavaScript project with 8,268 GitHub stars. SynthScan v2.0 examined 34,300 lines of code across 71 source files, recording 192 pattern matches distributed across 3 syntactic categories. The overall adjusted score of 47.2 places this repository in the Strong AI signal 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).

47.2
Adjusted Score
47.2
Raw Score
100%
Time Factor
2026-07-27
Last Push
8.3K
Stars
JavaScript
Language
34.3K
Lines of Code
71
Files
192
Pattern Hits
2026-08-02
Scan Date
2.44
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

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.

No multi-scan history yet — run the scanner again to build trend data.

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 173HIGH 0MEDIUM 0LOW 19

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 192 distinct pattern matches across 3 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.

Hallucination Indicators173 hits · 1598 pts
SeverityFileLineSnippetContext
CRITICALReleaseNotes.md211expect(true).to.be.true.and.not.false();CODE
CRITICALtest/expect.js914 expect('foo').to.have.length.of.at.least(4, 'blah');CODE
CRITICALtest/expect.js918 expect('foo', 'blah').to.have.length.of.at.least(4);CODE
CRITICALtest/expect.js926 expect([ 1, 2, 3 ]).to.have.length.of.at.least(4, 'blah');CODE
CRITICALtest/expect.js934 expect([ 1, 2, 3, 4 ]).to.not.have.length.of.at.least(4, 'blah');CODE
CRITICALtest/expect.js938 expect([ 1, 2, 3, 4 ]).to.not.have.lengthOf.at.least(4, 'blah');CODE
CRITICALtest/expect.js977 expect(new Map()).to.have.length.of.at.least(0);CODE
CRITICALtest/expect.js985 expect(map).to.have.length.of.at.least(3);CODE
CRITICALtest/expect.js989 expect(map).to.have.length.of.at.least(4, 'blah');CODE
CRITICALtest/expect.js996 expect(new Set()).to.have.length.of.at.least(0);CODE
CRITICALtest/expect.js1004 expect(set).to.have.length.of.at.least(3);CODE
CRITICALtest/expect.js1008 expect(set).to.have.length.of.at.least(4, 'blah');CODE
CRITICALtest/expect.js1198 expect('foo').to.have.length.of.at.most(2, 'blah');CODE
CRITICALtest/expect.js1202 expect('foo', 'blah').to.have.length.of.at.most(2);CODE
CRITICALtest/expect.js1210 expect([ 1, 2, 3 ]).to.have.length.of.at.most(2, 'blah');CODE
CRITICALtest/expect.js1218 expect([ 1, 2 ]).to.not.have.length.of.at.most(2, 'blah');CODE
CRITICALtest/expect.js1222 expect([ 1, 2 ]).to.not.have.lengthOf.at.most(2, 'blah');CODE
CRITICALtest/expect.js1250 expect(1).to.have.length.of.at.most(0, 'blah');CODE
CRITICALtest/expect.js1254 expect(1, 'blah').to.have.length.of.at.most(0);CODE
CRITICALtest/expect.js1261 expect(new Map()).to.have.length.of.at.most(0);CODE
CRITICALtest/expect.js1269 expect(map).to.have.length.of.at.most(3);CODE
CRITICALtest/expect.js1273 expect(map).to.have.length.of.at.most(2, 'blah');CODE
CRITICALtest/expect.js1280 expect(new Set()).to.have.length.of.at.most(0);CODE
CRITICALtest/expect.js1288 expect(set).to.have.length.of.at.most(3);CODE
CRITICALtest/expect.js1292 expect(set).to.have.length.of.at.most(2, 'blah');CODE
CRITICALtest/expect.js1321 expect(now).to.have.length.of.at.most(2, 'blah');CODE
CRITICALtest/expect.js1325 expect('foo', 'blah').to.have.length.of.at.most(now);CODE
CRITICALtest/expect.js1329 expect([ 1, 2, 3 ]).to.not.have.length.of.at.most(now, 'blah');CODE
CRITICALtest/expect.js2045 expect(obj).to.not.have.deep.own.property('a', {z: 1});CODE
CRITICALtest/expect.js2048 expect(obj).to.not.have.deep.own.property('a', {b: 7});CODE
CRITICALtest/expect.js2051 expect(obj).to.not.have.deep.own.property('toString', Object.prototype.toString);CODE
CRITICALtest/expect.js2136 expect(obj).to.not.have.deep.nested.property('a.b', {c: 7});CODE
CRITICALtest/expect.js2137 expect(obj).to.not.have.deep.nested.property('a.b', {z: 1});CODE
CRITICALtest/expect.js2138 expect(obj).to.not.have.deep.nested.property('a.z', {c: 1});CODE
CRITICALtest/expect.js2701 expect(testMap).to.not.contain.all.deep.keys({thisIs: 'anExampleObject'}, 'thisDoesNotExist');CODE
CRITICALtest/expect.js2703 expect(testMap).to.not.have.any.deep.keys({iDoNot: 'exist'});CODE
CRITICALtest/expect.js2704 expect(testMap).to.not.have.any.deep.keys('thisIsNotAkey', {iDoNot: 'exist'}, {33: 20});CODE
CRITICALtest/expect.js2705 expect(testMap).to.not.have.all.deep.keys('thisDoesNotExist', 'thisToo', {doingThisBecauseOf: 'referential equality'CODE
CRITICALtest/expect.js2712 expect(testMap).to.not.have.any.deep.keys([{13: 37}, 'thisDoesNotExist', 'thisToo']);CODE
CRITICALtest/expect.js2713 expect(testMap).to.not.have.any.deep.keys([20, 1, {13: 37}]);CODE
CRITICALtest/expect.js2714 expect(testMap).to.not.have.all.deep.keys([{thisIs: 'anExampleObject'}, {'iDoNot': 'exist'}]);CODE
CRITICALtest/expect.js2828 expect(testSet).to.not.contain.all.deep.keys({thisIs: 'anExampleObject'}, 'thisDoesNotExist');CODE
CRITICALtest/expect.js2830 expect(testSet).to.not.have.any.deep.keys({iDoNot: 'exist'});CODE
CRITICALtest/expect.js2831 expect(testSet).to.not.have.any.deep.keys('thisIsNotAkey', {iDoNot: 'exist'}, {33: 20});CODE
CRITICALtest/expect.js2832 expect(testSet).to.not.have.all.deep.keys('thisDoesNotExist', 'thisToo', {doingThisBecauseOf: 'referential equality'CODE
CRITICALtest/expect.js2839 expect(testSet).to.not.have.any.deep.keys([{13: 37}, 'thisDoesNotExist', 'thisToo']);CODE
CRITICALtest/expect.js2840 expect(testSet).to.not.have.any.deep.keys([20, 1, {13: 37}]);CODE
CRITICALtest/expect.js2841 expect(testSet).to.not.have.all.deep.keys([{thisIs: 'anExampleObject'}, {'iDoNot': 'exist'}]);CODE
CRITICALtest/expect.js896 expect('foo').to.have.length.of.at.least(2);CODE
CRITICALtest/expect.js898 expect([ 1, 2, 3 ]).to.have.length.of.at.least(2);CODE
CRITICALtest/expect.js1180 expect('foo').to.have.length.of.at.most(4);CODE
CRITICALtest/expect.js1182 expect([ 1, 2, 3 ]).to.have.length.of.at.most(4);CODE
CRITICALtest/expect.js2064 expect(obj).to.not.have.deep.own.property('a', {b: 1}, 'blah');CODE
CRITICALtest/expect.js2149 expect(obj).to.not.have.deep.nested.property('a.b', {c: 1}, 'blah');CODE
CRITICALtest/utilities.js434 expect([1, 2, 3]).to.be.a.thing.with.length.above(2);CODE
CRITICALtest/utilities.js588 expect([1, 2, 3]).to.be.an.foo.length.below(1000);CODE
CRITICALtest/utilities.js594 expect([1, 2, 3]).to.be.a.foo.with.length.above(2);CODE
CRITICALtest/should.js849 (new Map()).should.have.length.of.at.least(0);CODE
CRITICALtest/should.js857 map.should.have.length.of.at.least(3);CODE
CRITICALtest/should.js858 map.should.have.lengthOf.at.least(3);CODE
113 more matches not shown…
Hyper-Verbose Identifiers14 hits · 18 pts
SeverityFileLineSnippetContext
LOWtest/configuration.js76 function badOverwrittenPropertyAssertion() {CODE
LOWtest/configuration.js82 function badOverwrittenMethodAssertion() {CODE
LOWtest/configuration.js85 function badChainableMethodAssertion() {CODE
LOWtest/configuration.js88 function badOverwrittenChainableMethodAssertion() {CODE
LOWtest/configuration.js370 function badOverwrittenPropertyAssertion() {CODE
LOWtest/configuration.js376 function badOverwrittenMethodAssertion() {CODE
LOWtest/configuration.js379 function badChainableMethodAssertion() {CODE
LOWtest/configuration.js382 function badOverwrittenChainableMethodAssertion() {CODE
LOWlib/chai/core/assertions.js2157function assertOwnPropertyDescriptor(name, descriptor, msg) {CODE
LOWlib/chai/utils/overwriteProperty.js55 get: function overwritingPropertyGetter() {CODE
LOWlib/chai/utils/getOwnEnumerableProperties.js22export function getOwnEnumerableProperties(obj) {CODE
LOWlib/chai/utils/getOwnEnumerablePropertySymbols.js20export function getOwnEnumerablePropertySymbols(obj) {CODE
LOWlib/chai/utils/overwriteChainableMethod.js59 function overwritingChainableMethodGetter() {CODE
LOWlib/chai/utils/overwriteChainableMethod.js74 chainableBehavior.method = function overwritingChainableMethodWrapper() {CODE
Over-Commented Block5 hits · 5 pts
SeverityFileLineSnippetContext
LOWlib/chai/utils/addChainableMethod.js121 //COMMENT
LOWlib/chai/utils/overwriteProperty.js61 // the `lockSsfi` flag isn't set and proxy protection is disabled.COMMENT
LOWlib/chai/utils/overwriteMethod.js61 // function to be the starting point for removing implementation frames fromCOMMENT
LOWlib/chai/utils/addProperty.js41 Object.defineProperty(ctx, name, {COMMENT
LOWlib/chai/utils/addMethod.js41 /**COMMENT