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Copy/paste detector for programming source code.

jscpd is a tool for detect copy/paste "design pattern" in programming source code.

Supported languages
JavaScript Java YAML
CoffeeScript C++ Haxe
PHP C# TypeScript
Go Python Mixed HTML
Less CSS erlang
Swift xml/xslt Objective-C
Puppet Twig Vue.js
Scala Lua

If you need support language not from list feel free to create request.


Dependency Status Build Status Coverage Status Stories in Ready




npm install jscpd -g


jscpd --path my_project/ --languages javascript,coffee

jscpd -f "**/*.js" -e "**/node_modules/**"

jscpd --files "**/*.js" --exclude "**/*.min.js" --output report.xml

jscpd --files "**/*.js" --exclude "**/*.min.js" --reporter json --output report.json

jscpd --languages-exts javascript:es5,es6,es7,js;php:php5

jscpd --config test/.cpd.yaml


If you have file .cpd.yaml in your directory

  - javascript
  - coffeescript
  - typescript
  - php
  - python
  - jsx
  - haxe
  - yaml
  - css
  - ruby
  - go
  - swift
  - twig
  - java
  - clike    # c++, c, objective-c source 
  - csharp      # c# source 
  - htmlmixed   # html mixed source like knockout.js templates 
  - "test/**/*"
  - "**/*.min.js"
  - "**/*.mm.js"
reporter: json
        - coffeee
        - es
        - es5
        - es6
        - es7

and run jscpd command, you will check code for duplicates according config from .cpd.yaml


# coffeescript 
jscpd = require('jscpd')
result = jscpd::run
  path: 'my/project/folder'
  files: '**/*.js'
  exclude: ['**/*.min.js''**/node_modules/**']
  reporter: json

Please see the minimatch documentation for more details.


Option Type Default Description
-l, --min-lines [NUMBER] 5 min size of duplication in code lines
-t, --min-tokens [NUMBER] 70 min size of duplication in code tokens
-f, --files [STRING] * glob pattern for find code
-r, --reporter [STRING] xml reporter name or path
-x, --xsl-href [STRING] - path to xsl file for include to xml report
-e, --exclude [STRING] - directory to ignore
--languages-exts [STRING] - list of languages with file extensions (e.g. language:ext1,ext2;language:ext3)
-g, --languages [STRING] All supported list of languages which scan for duplicates, separated with coma
-o, --output [PATH] - path to report file
-c, --config [PATH] - path to config yml file (e.g. .cpd.yml)
--verbose - show full info about copies
--skip-comments false - skip comments in code when duplications finding
-b, --blame false - blame authors of duplications (get information about authors from git)
-p, --path [PATH] Current dir path to code
--limit [NUMBER] 50 limit of allowed duplications, if real duplications percent more then limit jscpd exit with error
-d, --debug - show debug information (options list and selected files)
-v, --version - Display the current version
-h, --help - Display help and usage details

Verbose output:

verbose duplication

Blame mode use information from git blame and concat it with duplications report:

blame duplication


jscpd shipped with two standard reporters xml and json. It is possible to write custom reporter script too. For hooking reporter up wrap it into node module and provide path to it as reporter parameter e.g. ./scripts/ (works with javascript too).

Custom reporter is a function which is executed into context of Report ( class and thus has access to the report object and options. Expected output is array with following elements:

[raw, dump, log]

  • raw is raw report object which will be passed through.
  • dump is report which will be written into output file if any provided.
  • log custom log output for cli.

At least one of raw or dump needs to be provided, log is fully optional.

XSLT reports support

You can point xsl file for add it to xml report

jscpd -x reporters-xslt/simple.xsl -p test/fixtures/ -r xml -o report.xml

In this case report.xml will include following lines:

<?xml version='1.0' encoding='UTF-8' ?>
<?xml-stylesheet type="text/xsl" href="reporters-xslt/simple.xsl"?>
    <!-- ... -->

If you open xml file in browser template from reporters-xslt/simple.xsl will apply to your xml and show pretty html report. You can find example of xsl template in reporters-xslt folder.


  • JSCPD Error 01: {language} in not supported - error will show if you try to find duplication in not supported language
  • JSCPD Error 02: can't read config file {path} - you use wrong path to file or file is broken

Run tests

  npm test
  npm run coverage


Project changelog


Project plans


The MIT License


Thanks to Mathieu Desvé for grunt-jscpd. Thanks to Yannick Croissant for gulp-jscpd. Thanks to linslin for grunt-jscpd-reporter.

Project developed with PyCharm alt pycharm Thanks to JetBrains company for license key. Feel free to contribute this project and you will have chance to get license key too.