Like Unix Expect: Automate Command Line Programs in Node.js with Suppose

Have you ever heard of the command line program expect? Basically, expect allows you to automate command line programs. suppose is a programmable Node.js module that allows the same behavior.

Why would you do this? Maybe you want to automate a ssh session? Or, maybe you want to test the external interface of on of your Node.js command line scripts.

Install: npm install suppose


suppose('npm', ['init'])
  .on('name: (awesome) ').respond('awesome_package\n')
  .on('version: (0.0.0) ').respond('0.0.1\n')
  .on('description: ').respond("It's an awesome package man!\n")
  .on('entry point: (index.js) ').respond("\n")
  .on('test command: ').respond('npm test\n')
  .on('git repository: ').respond("\n")
  .on('keywords: ').respond('awesome, cool\n')
  .on('author: ').respond('JP Richardson\n')
  .on('license: (BSD) ').respond('MIT\n')
  .on('ok? (yes) ' ).respond('yes\n')
    assert(code === 0);
    var packageFile = '/tmp/awesome/package.json';
    fs.readFile(packageFile, function(err, data){
        var packageObj = JSON.parse(data.toString());
        assert( === 'awesome_package');
        assert(packageObj.version === '0.0.1');
        assert(packageObj.description === "It's an awesome package man!");
        assert(packageObj.main === 'index.js');
        assert(packageObj.scripts.test === 'npm test');
        assert(packageObj.keywords[0] === 'awesome');
        assert(packageObj.keywords[1] === 'cool');
        assert( === 'JP Richardson');
        assert(packageObj.license === 'MIT');

Pretty easy, huh? You can grab the source on Github.

If you made it this far, you should follow me on Twitter.


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