title: In node package.json, invoke script from another script with extra parameter, in this case add mocha watcher
body: <p>in node's package.json I would like to reuse a command that I already have in a 'script'.</p>
  
  <p>Here is the practical example</p>
  
  <p>instead of (note the extra <strong>-w</strong> on the <strong>watch</strong> script):</p>
  
  <pre><code>"scripts": {
               "test" : "./node_modules/mocha/bin/mocha --compilers coffee:coffee-script/register --recursive -R list",
               "watch": "./node_modules/mocha/bin/mocha --compilers coffee:coffee-script/register --recursive -R list -w",
             }
  </code></pre>
  
  <p>I would like to have something like</p>
  
  <pre><code>"scripts": {
               "test" : "./node_modules/mocha/bin/mocha --compilers coffee:coffee-script/register --recursive -R list",
               "watch": "npm run script test" + "-w",
             }
  </code></pre>
  
  <p>which doesn't work (can't do string concats in json), but you should get what I would like</p>
  
  <p>I know that npm scripts support:
   - &amp; (parallel execution) 
   - &amp;&amp; (sequencial execution)</p>
  
  <p>so maybe there is another option?</p>