copydiff

copydiff is a Bun + TypeScript helper that augments git diff output with copy/clone awareness using jscpd while preserving Git's moved-line coloring.

• Detect moved code (across files, using git color-moved)
• Detect similar code (across files, using jscpd)

code from bluesky-social/social-app

Install

bun i -g @houkanshan/copydiff

Usage

Filter mode:

copydiff abc123...efg456

Generate HTML output:

copydiff base...head --html out.html

HTML output includes syntax highlighting, diff-style background blocks, and copy highlights with expandable source details.

Wrapper mode:

Options

• --stdin read diff from stdin.
• --html <path> write a light-mode HTML diff with copy highlights and expandable source details.
• --no-fold-pure disable folding for pure copies.
• --copy-color <spec> set copy highlight color using git color syntax (defaults to color.diff.newMoved).
• --no-copy-color disable copy highlighting.
• --pure-threshold <0..1> similarity threshold for pure copies (default 0.98).
• --min-fold-lines <n> minimum lines to fold (default 12).
• --min-lines <n> minimum lines for jscpd (default 8).
• --min-tokens <n> minimum tokens for jscpd (default min-lines * 2).
• --ignore <glob,glob> ignored globs for jscpd.
• --cache <on|off> enable clone cache (default on).
• --verbose log jscpd output.
• --diff-config <force|respect> set git diff config mode for wrapper mode (default force).
• --scan-scope <all|changed-types> scan the whole repo (all, default) or only files with extensions present in the diff (changed-types). Note: .gitignore is always honored for clone scanning.

Exit codes

• 0 success
• 2 invalid args
• 3 jscpd failure

Local Development

bun install
bun link