run-when-changed

Selectively executes commands when watched files are changed (Nix & Win32).

Installation

npm install --save-dev run-when-changed

Usage

Usage: run-when-changed --watch <glob> --match [glob] --exec <cmd> (--watch <glob> --match [glob] --exec <cmd>)

Selectively executes commands when watched files are changed.

Options:

  -h, --help                    Output usage information
  -w, --watch <glob>            A glob to watch, starts a new group
  -e, --exec <cmd>              Command to execute, eg "echo %s"
  -m, --match [glob]            Only files that match will be executed
  -i, --interval [milliseconds] Interval to pass to fs.watchFile in milliseconds
  -d, --debounce [milliseconds] Delay for events called in succession for the same file/event in milliseconds
  -m, --mode [auto|watch|poll]  Force the watch mode. Either 'auto' (default), 'watch' (force native events), or 'poll' (force stat polling)
  -c, --cwd [directory]         The current working directory to base file patterns from. Default is process.cwd()
  --verbose                     Verbose mode

CMD format

Command line accepts the following tokens:

• %filedir - Changed file directory, relative to CWD.
• %filename - Changed file name and extension.
• %filepath - Changed file directory, file name and extension relative to CWD.
• %s - Same as %filepath.
• %package-json-dir - Full path to nearest folder that contains package.json.
• %full-filedir - Full absolute changed file directory.
• %full-filepath - Full absolute changed file directory, file name and extension.

Examples

Watching one or more glob

$ run-when-changed --watch "**/*.js" --exec "ls -la %s"
$ run-when-changed --watch "**/*.js" --watch "README.md" --exec "ls -la %s"

Executing multiple commands

Having more than one exec passed per watch will execute multiple commands per file when there's a change event.

$ run-when-changed --watch "**/*.js" --exec "ls -la %s" --exec "chmod +x %s"

Watching multiple globs

You can watch multiple globs and execute commands specific to each glob.

$ run-when-changed \
  --watch "**/*.js" --exec "ls -la %s" \  # executes `ls` for `*.js` files
  --watch "**/*.txt" --exec "rm %s" \     # executes `rm` for `*.txt` files

Filtering

# executes `ls` for `*-test.js` files
$ run-when-changed --watch "**/*.js" --filter "*-test.js" --exec "ls -la %s"

Running mocha

This command will execute mocha test runner for all tests/**/*-test.js files.

$ run-when-changed \
  --watch "tests/**/*-test.js" \
  --exec "mocha --require babel-register %s" \
  --verbose

NPM Package Usage Examples

Install locally (npm install --save-dev run-when-changed) then add the following to your package.json

Mocha

You can use npm run dev command to start a file watcher that will execute the test file you are working on without having to add .only.

{
  "scripts": {
    "dev": "run-when-changed --watch 'tests/**/*-test.js' --exec 'mocha --require babel-register %s'"
  }
}

Mocha & Babel

You can use npm run dev command to start a file watcher that will execute the test file you are working on without having to add .only and compile *.js files in the root folder using Babel.js.

{
  "scripts": {
    "dev": "run-when-changed.js --watch 'tests/**/*-test.js' --exec 'mocha --require babel-register %s' --watch '*.js' --exec 'babel %s --out-dir ./lib --source-maps'"
  }
}

Notes

1. filter and exec applies only to immediately preceeding watch
2. You can have as many filter and exec after one or many watch

License

ISC