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jscpd

jscpd documentation

jscpd - GitHub

Configuration in Mega-Linter

Variable Description Default value
COPYPASTE_JSCPD_ARGUMENTS User custom arguments to add in linter CLI call
Ex: -s --foo "bar"
COPYPASTE_JSCPD_FILTER_REGEX_INCLUDE Custom regex including filter
Ex: (src\|lib)
Include every file
COPYPASTE_JSCPD_FILTER_REGEX_EXCLUDE Custom regex excluding filter
Ex: (test\|examples)
Exclude no file
COPYPASTE_JSCPD_FILE_EXTENSIONS Allowed file extensions. "*" matches any extension, "" matches empty extension. Empty list excludes all files
Ex: [".py", ""]
Exclude every file
COPYPASTE_JSCPD_FILE_NAMES_REGEX File name regex filters. Regular expression list for filtering files by their base names using regex full match. Empty list includes all files
Ex: ["Dockerfile(-.+)?", "Jenkinsfile"]
Include every file
COPYPASTE_JSCPD_CONFIG_FILE jscpd configuration file name
Use LINTER_DEFAULT to let the linter find it
.jscpd.json
COPYPASTE_JSCPD_RULES_PATH Path where to find linter configuration file Workspace folder, then Mega-Linter default rules
COPYPASTE_JSCPD_DISABLE_ERRORS Run linter but consider errors as warnings false
COPYPASTE_JSCPD_DISABLE_ERRORS_IF_LESS_THAN Maximum number of errors allowed 0

IDE Integration

Use jscpd in your favorite IDE to catch errors before Mega-Linter !

IDE Extension Name Install
Visual Studio Code vscode-jscpd Install in VsCode

Mega-Linter Flavours

This linter is available in the following flavours

Flavor Description Embedded linters Info
all Default Mega-Linter Flavor 91 Docker Image Size (tag) Docker Pulls
dart Optimized for DART based projects 39 Docker Image Size (tag) Docker Pulls
documentation Mega-Linter for documentation projects 38 Docker Image Size (tag) Docker Pulls
dotnet Optimized for C, C++, C# or VB based projects 44 Docker Image Size (tag) Docker Pulls
go Optimized for GO based projects 40 Docker Image Size (tag) Docker Pulls
java Optimized for JAVA based projects 39 Docker Image Size (tag) Docker Pulls
javascript Optimized for JAVASCRIPT or TYPESCRIPT based projects 47 Docker Image Size (tag) Docker Pulls
php Optimized for PHP based projects 42 Docker Image Size (tag) Docker Pulls
python Optimized for PYTHON based projects 47 Docker Image Size (tag) Docker Pulls
ruby Optimized for RUBY based projects 39 Docker Image Size (tag) Docker Pulls
rust Optimized for RUST based projects 39 Docker Image Size (tag) Docker Pulls
salesforce Optimized for Salesforce based projects 41 Docker Image Size (tag) Docker Pulls
scala Optimized for SCALA based projects 39 Docker Image Size (tag) Docker Pulls
swift Optimized for SWIFT based projects 39 Docker Image Size (tag) Docker Pulls
terraform Optimized for TERRAFORM based projects 43 Docker Image Size (tag) Docker Pulls

Behind the scenes

How are identified applicable files

  • If this linter is active, all files will always be linted

Example calls

jscpd --output ./report/copy-paste/ .
jscpd --output ./report/copy-paste/ -c .jscpd.json .

Help content

Usage: jscpd [options] <path ...>

detector of copy/paste in files

Options:
  -V, --version              output the version number
  -l, --min-lines [number]   min size of duplication in code lines (Default is
                             5)
  -k, --min-tokens [number]  min size of duplication in code tokens (Default is
                             50)
  -x, --max-lines [number]   max size of source in lines (Default is 1000)
  -z, --max-size [string]    max size of source in bytes, examples: 1kb, 1mb,
                             120kb (Default is 100kb)
  -t, --threshold [number]   threshold for duplication, in case duplications >=
                             threshold jscpd will exit with error
  -c, --config [string]      path to config file (Default is .jscpd.json in
                             <path>)
  -i, --ignore [string]      glob pattern for files what should be excluded
                             from duplication detection
  -r, --reporters [string]   reporters or list of reporters separated with
                             comma to use (Default is time,console)
  -o, --output [string]      reporters to use (Default is ./report/)
  -m, --mode [string]        mode of quality of search, can be "strict", "mild" and "weak" (Default is "function mild(token) {
      return strict(token) && token.type !== 'empty' && token.type !== 'new_line';
  }")
  -f, --format [string]      format or formats separated by comma (Example
                             php,javascript,python)
  -p, --pattern [string]     glob pattern to file search (Example **/*.txt)
  -b, --blame                blame authors of duplications (get information
                             about authors from git)
  -s, --silent               do not write detection progress and result to a
                             console
  --store [string]           use for define custom store (e.g. --store leveldb
                             used for big codebase)
  -a, --absolute             use absolute path in reports
  -n, --noSymlinks           dont use symlinks for detection in files
  --ignoreCase               ignore case of symbols in code (experimental)
  -g, --gitignore            ignore all files from .gitignore file
  --formats-exts [string]    list of formats with file extensions
                             (javascript:es,es6;dart:dt)
  -d, --debug                show debug information, not run detection
                             process(options list and selected files)
  -v, --verbose              show full information during detection process
  --list                     show list of total supported formats
  --skipLocal                skip duplicates in local folders, just detect
                             cross folders duplications
  -h, --help                 display help for command

Installation on mega-linter Docker image

  • NPM packages (node.js):

Example success log

Results of jscpd linter (version 3.3.22)
See documentation on https://nvuillam.github.io/mega-linter/descriptors/copypaste_jscpd/
-----------------------------------------------

[SUCCESS] .automation/test/copypaste/good
    ┌────────┬────────────────┬─────────────┬──────────────┬──────────────┬──────────────────┬───────────────────┐
    │ Format │ Files analyzed │ Total lines │ Total tokens │ Clones found │ Duplicated lines │ Duplicated tokens │
    ├────────┼────────────────┼─────────────┼──────────────┼──────────────┼──────────────────┼───────────────────┤
    │ go     │ 2              │ 12          │ 52           │ 0            │ 0 (0%)           │ 0 (0%)            │
    ├────────┼────────────────┼─────────────┼──────────────┼──────────────┼──────────────────┼───────────────────┤
    │ Total: │ 2              │ 12          │ 52           │ 0            │ 0 (0%)           │ 0 (0%)            │
    └────────┴────────────────┴─────────────┴──────────────┴──────────────┴──────────────────┴───────────────────┘
    Found 0 clones.
    HTML report saved to report/copy-paste/html/
    Detection time:: 42.298ms

Example error log

Results of jscpd linter (version 3.3.22)
See documentation on https://nvuillam.github.io/mega-linter/descriptors/copypaste_jscpd/
-----------------------------------------------

[ERROR] .automation/test/copypaste/bad
    Clone found (go):
     - copypaste_bad_1.go [1:1 - 33:2] (32 lines, 222 tokens)
       copypaste_bad_2.go [1:1 - 33:2]

    ┌────────┬────────────────┬─────────────┬──────────────┬──────────────┬──────────────────┬───────────────────┐
    │ Format │ Files analyzed │ Total lines │ Total tokens │ Clones found │ Duplicated lines │ Duplicated tokens │
    ├────────┼────────────────┼─────────────┼──────────────┼──────────────┼──────────────────┼───────────────────┤
    │ go     │ 2              │ 64          │ 444          │ 1            │ 32 (50%)         │ 222 (50%)         │
    ├────────┼────────────────┼─────────────┼──────────────┼──────────────┼──────────────────┼───────────────────┤
    │ Total: │ 2              │ 64          │ 444          │ 1            │ 32 (50%)         │ 222 (50%)         │
    └────────┴────────────────┴─────────────┴──────────────┴──────────────┴──────────────────┴───────────────────┘
    Found 1 clones.
    HTML report saved to report/copy-paste/html/
    ERROR: jscpd found too many duplicates (50%) over threshold (0%)
    Error: ERROR: jscpd found too many duplicates (50%) over threshold (0%)
        at ThresholdReporter.report (/node_modules/@jscpd/finder/dist/reporters/threshold.js:12:19)
        at /node_modules/@jscpd/finder/dist/in-files-detector.js:82:26
        at Array.forEach (<anonymous>)
        at /node_modules/@jscpd/finder/dist/in-files-detector.js:81:28