Sample script for with Promises for updating an Apex class in Force.com using the Tooling API with node.

tooling.js

var  Q = require("q"),
  request = require('request');

// call with the following
// var apexClassId = "01pi0000004kbvAAAQ";  // the id of the apex class to update
// var newCode = "public class Test1 { public void sayHelloOnceAgain() { } }";   // pass in some code
// var connetion = resp object from nforce org.authenticate

function updateApex(apexClassId, newCode, connection) {

  var deferred = Q.defer();
  var bearer = connection.access_token;

  console.log("==== STARTING NEW DEPLOY ====");

  createContainer()
    .then(addUpdatedCode)
    .then(deploy)
    .then(function(results) {
      deferred.resolve(results);
    })
    .fail(function(err) {
      console.log("== failure: " + err);
      deferred.reject(err);
    });

  function deleteContainer(metadataContainerId) {
    var deferred = Q.defer();

    var options = {
        url: connection.instance_url + '/services/data/v28.0/tooling/sobjects/MetadataContainer/' + metadataContainerId,
        method: 'DELETE',
        headers: {
            'Content-Type': 'application/json',
            'Authorization': 'Bearer ' + bearer
        }
    };

    function callback(error, response, body) {
      if (!error && response.statusCode == 204) {
        console.log("Deleted deployment container: " + metadataContainerId);
        deferred.resolve("Deployment complete!");
      } else {
        console.log(response.statusCode);
        var result = JSON.parse(body);
        deferred.reject("Failed to delete metadata container.");
        console.log(result);
      }
    }
    // make the request
    request(options, callback);  

    return deferred.promise;
  }          

  function checkDeployState(containerAsyncRequestId) {
    var options = {
        url: connection.instance_url + '/services/data/v28.0/tooling/sobjects/ContainerAsyncRequest/' + containerAsyncRequestId,
        headers: {
            'Content-Type': 'application/json',
            'Authorization': 'Bearer ' + bearer
        }
    };

    function callback(error, response, body) {
      if (!error && response.statusCode == 200) {
        var result = JSON.parse(body);
        if (result.State === "Queued") {
          console.log("Status is currently queued. Checking deploy state again.");
          checkDeployState(containerAsyncRequestId);
        } else {
          if (result.State === "Completed") {
            console.log("W00t! Code successfully deployed");
          } else if (result.State === "Failed") {
            console.log("Deployment failed with: ");
            console.log(result.CompilerErrors);
          } else if (result.State === "Error") {
            console.log("Deployment failed with error: ");
            console.log(result.ErrorMsg);
          } else {
            console.log("Deploy finished with a status of: " + result.State);            
            console.log(result);            
          }
          deleteContainer(result.MetadataContainerId);

        }

      } else {
        var result = JSON.parse(body);
        console.log(result);
      }
    }
    // make the request
    request(options, callback);  
  }

  function createContainer() {
    var deferred = Q.defer();

    var options = {
        url: connection.instance_url + '/services/data/v28.0/tooling/sobjects/MetadataContainer',
        method: 'POST',
        body: '{"Name":"AwesomeContainer"}',
        headers: {
            'Content-Type': 'application/json',
            'Authorization': 'Bearer ' + bearer
        }
    };

    function callback(error, response, body) {
      if (!error && response.statusCode == 201) {
        var result = JSON.parse(body);
        console.log("Created MetadataContainer: " + result.id)
        deferred.resolve(result.id);
      } else {
        console.log(response.statusCode);
        var result = JSON.parse(body);
        deferred.reject("Failed to create a metadata container.");
        console.log(result);
      }
    }
    // make the request
    request(options, callback);  

    return deferred.promise;
  }

  function addUpdatedCode(metadataContainerId) {
    var deferred = Q.defer();

    var options = {
        url: connection.instance_url + '/services/data/v28.0/tooling/sobjects/ApexClassMember',
        method: 'POST',
        body: '{"MetadataContainerId":"'+metadataContainerId+'", "ContentEntityId":"'+apexClassId+'", "body": "'+newCode+'"}',
        headers: {
            'Content-Type': 'application/json',
            'Authorization': 'Bearer ' + bearer
        }
    };

    function callback(error, response, body) {
      if (!error && response.statusCode == 201) {
        var result = JSON.parse(body);
        console.log("Created ApexClassMember: " + result.id)
        deferred.resolve(metadataContainerId);
      } else {
        console.log(response.statusCode);
        var result = JSON.parse(body);
        deferred.reject("Failed to add updated code.");
        console.log(result);
      }
    }
    // make the request
    request(options, callback);  

    return deferred.promise;
  }  

  function deploy(metadataContainerId) {
    var deferred = Q.defer();

    var options = {
        url: connection.instance_url + '/services/data/v28.0/tooling/sobjects/ContainerAsyncRequest',
        method: 'POST',
        body: '{"MetadataContainerId":"'+metadataContainerId+'", "isCheckOnly": false}',
        headers: {
            'Content-Type': 'application/json',
            'Authorization': 'Bearer ' + bearer
        }
    };

    function callback(error, response, body) {
      if (!error && response.statusCode == 201) {
        var result = JSON.parse(body);
        console.log("Deployed code with id: " + result.id);  
        // check the state of the deployment
        checkDeployState(result.id);
        deferred.resolve(metadataContainerId);
      } else {
        console.log(response.statusCode);
        var result = JSON.parse(body);
        deferred.reject("Failed to deploy code.");
        console.log(result);
      }
    }
    // make the request
    request(options, callback);  

    return deferred.promise;
  }    

  return deferred.promise;

}

exports.updateApex = updateApex;