Repository Analysis

gildas-lormeau/zip.js

JavaScript library to zip and unzip files supporting multi-core compression, web streams, zip64, split files, data encryption, and deflate64 decompression.

5.1 Low AI signal View on GitHub

Analysis Overview

This report presents the forensic synthetic code analysis of gildas-lormeau/zip.js, a JavaScript project with 3,871 GitHub stars. SynthScan v2.0 examined 41,550 lines of code across 322 source files, recording 206 pattern matches distributed across 5 syntactic categories. The overall adjusted score of 5.1 places this repository in the Low 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).

5.1
Adjusted Score
5.1
Raw Score
100%
Time Factor
2026-07-14
Last Push
3.9K
Stars
JavaScript
Language
41.5K
Lines of Code
322
Files
206
Pattern Hits
2026-07-14
Scan Date
0.00
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 0HIGH 1MEDIUM 0LOW 205

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 206 distinct pattern matches across 5 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.

Fake / Example Data176 hits · 177 pts
SeverityFileLineSnippetContext
LOWindex.d.ts2342 * const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tinciduCOMMENT
LOWindex.d.ts2342 * const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tinciduCOMMENT
LOWtests/all/test-split-data.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-split-data.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-overlapping-entries.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-overlapping-entries.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-fs-export-options.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-fs-export-options.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-crypto-tampered.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-crypto-tampered.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-fs-unzip-store.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-fs-unzip-store.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-comments.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-comments.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-fs-arraybuffer.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-fs-arraybuffer.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-remove-entry.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-remove-entry.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-last-access-date.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-last-access-date.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-malformed-zip.js3const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-malformed-zip.js3const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-fs-remove.js3const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-fs-remove.js3const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-zip64-crypto.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-zip64-crypto.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-worker-error.js6const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-worker-error.js6const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-zip64.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-zip64.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-golden-output.js24 await zipWriter.add("text.txt", new zip.TextReader("Lorem ipsum dolor sit amet"), { comment: "entry comment" });CODE
LOWtests/all/test-golden-output.js24 await zipWriter.add("text.txt", new zip.TextReader("Lorem ipsum dolor sit amet"), { comment: "entry comment" });CODE
LOWtests/all/test-fs-http-import.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-fs-http-import.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-zip64-local-compressed-size.js52 const text = "Lorem ipsum dolor sit amet ".repeat(80);CODE
LOWtests/all/test-zip64-local-compressed-size.js52 const text = "Lorem ipsum dolor sit amet ".repeat(80);CODE
LOWtests/all/test-wrapped.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-wrapped.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-writer-edge-cases.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-writer-edge-cases.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-writer-js-codec-fallback.js15const CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit. ".repeat(256);CODE
LOWtests/all/test-writer-js-codec-fallback.js15const CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit. ".repeat(256);CODE
LOWtests/all/test-split-zip.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-split-zip.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-zip64-auto.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-zip64-auto.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-zip64-no-compression.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-zip64-no-compression.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-custom-io.js3const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-custom-io.js3const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-zip64-buffered-no-data-descriptor.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-zip64-buffered-no-data-descriptor.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-store.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-store.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-readable-zip-stream.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-readable-zip-stream.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-zip-streams.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-zip-streams.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-fs-metadata.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
LOWtests/all/test-fs-metadata.js5const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt CODE
116 more matches not shown…
Hyper-Verbose Identifiers24 hits · 24 pts
SeverityFileLineSnippetContext
LOWtests/all/test-malformed-zip.js81function addCentralDirectoryExtraField(array, extraField, patchDirectoryRecord) {CODE
LOWtests/all/test-abort-buffered-flush-offset.js114function firstCentralDirectoryOffset(bytes) {CODE
LOWtests/all/test-abort-buffered-flush-offset.js124function endOfCentralDirectoryOffset(bytes) {CODE
LOWtests/all/test-writer-edge-cases.js22async function testDuplicateDirectoryName() {CODE
LOWtests/all/test-io-edge-cases.js19async function testSplitDataWriterExactFill() {CODE
LOWtests/all/test-io-edge-cases.js48async function testHttpReaderIgnoredRangeRequest() {CODE
LOWtests/all/test-use-unicode-file-names.js30async function assertLanguageEncodingFlagIs(expectedLanguageEncodingFlag, blobWriter) {CODE
LOWtests/all/test-keep-order-concurrent.js55async function testFailureDoesNotReorderOrPollute() {CODE
LOWtests/all/test-end-of-central-directory.js146function stuffWithUnreachableRecords(array, count) {CODE
LOWtests/all/test-end-of-central-directory.js186function countEndOfDirectorySignatures(array) {CODE
LOWtests/all/test-fs-import-edge-cases.js23async function testDirectoryWithoutSlash() {CODE
LOWtests/all/test-fs-import-edge-cases.js41async function testImplicitDirectoryMetadata() {CODE
LOWtests/all/test-fs-import-edge-cases.js53async function testExplicitDirectoryMetadata() {CODE
LOWtests/all/test-fs-import-edge-cases.js93async function testReadOptionsPrecedence() {CODE
LOWlib/zip-module-wasm.js60function terminateWorkersAndModule() {CODE
LOWlib/core/zip-fs.js978async function transformToFileSystemhandle(entry) {CODE
LOWlib/core/zip-fs.js995async function transformToFileSystemhandles(entry) {CODE
LOWlib/core/zip-reader.js960function readExtraFieldExtendedTimestamp(extraFieldExtendedTimestamp, directory, localDirectory) {CODE
LOWlib/core/zip-reader.js1108async function findEndOfCentralDirectory(reader, rejectAmbiguous, maxAppendedDataSize) {CODE
LOWlib/core/zip-reader.js1167async function seekEndOfCentralDirectory(reader, maxAppendedDataSize, remoteProbeBudget) {CODE
LOWlib/core/zip-reader.js1207async function getCentralDirectoryReachability(reader, view, anchoredOffset, indexByte, offset, size, remoteProbeBudget)CODE
LOWlib/core/zip-writer.js999 function requestLockCurrentFileEntry() {CODE
LOWlib/core/zip-writer.js1729async function writeEndOfDirectoryRecord(zipWriter, comment, options, cdInfo) {CODE
LOWlib/core/streams/zip-entry-stream.js221function pipeThroughCommpressionStream(readable, useCompressionStream, options, CompressionStreamNative, CompressionStreCODE
Synthetic Comment Markers1 hit · 8 pts
SeverityFileLineSnippetContext
HIGHlib/core/codec-worker.js199 // supplied through config (e.g. the pure-JS port) stays usable and is kept as requested.COMMENT
Over-Commented Block4 hits · 4 pts
SeverityFileLineSnippetContext
LOWREADME.md41COMMENT
LOWREADME.md101// Creates a ZipWriter object writing data into `zipFileStream.writable`, addsCOMMENT
LOWbenchmarks/bench-crc.js1// Write-path CRC strategy, native CompressionStream. Compares the two ways zip.js can obtain theCOMMENT
LOWlib/core/util/opfs-temp-stream.js41// It is meant for the buffered-write path (keep-order concurrent `add()`, non-seekable output, ...),COMMENT
Overly Generic Function Names1 hit · 1 pts
SeverityFileLineSnippetContext
LOWlib/core/zip-reader.js518 async function getData() {CODE