dup-code-check

中文文档

dup-code-check is a toolbox for detecting duplicates/similarity in codebases. It ships as a Rust CLI binary; Node.js is used as an installation option via npm.

• CI: .github/workflows/ci.yml
• Docs: https://omne42.github.io/dup-code-check/ (VitePress; sources in docs/; not shipped in the npm package)

What it does (MVP)

• Duplicate file detection (ignores ASCII whitespace differences)
  • Single root or multiple roots
  • Optionally only report groups that span >= 2 roots (--cross-repo-only)
• Suspected duplicate code spans (--code-spans)
  • Normalizes by removing symbols + whitespace (keeps [A-Za-z0-9_])
  • Reports line ranges for occurrences
• Report mode (--report): multiple detectors/levels in one run
  • Defaults to --max-total-bytes=268435456 (256 MiB); override with --max-total-bytes
• Respects .gitignore by default
  • Note: in a Git repo, ignore rules include .gitignore, .git/info/exclude, and global Git ignores. Use --no-gitignore to include ignored files.

Install

Option A: Rust (recommended)

cargo build --release -p dup-code-check
./target/release/dup-code-check --help

Or install locally:

cargo install --path . --bin dup-code-check
dup-code-check --help

Option B: npm (builds from source on install)

npm i -D dup-code-check
npx dup-code-check --help

Requires:

• Node.js >= 22
• Rust toolchain 1.92.0 (pinned by rust-toolchain.toml)

Note: this package builds the Rust binary from source (Cargo), so Rust is required. For project installs, the build happens on first run; for global installs, it may run during postinstall.

Security note: building runs a native build (Cargo), which may execute dependency build scripts.

You can set DUP_CODE_CHECK_SKIP_BUILD=1 to disable builds (install + first run), then build manually:

cd node_modules/dup-code-check
npm run build

To build during install (project dependency), set DUP_CODE_CHECK_BUILD_ON_INSTALL=1.

To avoid running install scripts entirely, use npm_config_ignore_scripts=true:

npm_config_ignore_scripts=true npm i -D dup-code-check
npx dup-code-check --help

Quick examples

dup-code-check .
dup-code-check --cross-repo-only /repoA /repoB
dup-code-check --code-spans --cross-repo-only /repoA /repoB
dup-code-check --json --report .

Docs

To preview docs locally, clone the repo and run:

npm install --ignore-scripts
npm run docs:serve