Promises, pass additional parameters to then chain

Perhaps the most straightforward answer is:

P.then(function(data) { return doWork('text', data); });

Or, since this is tagged ecmascript-6, using arrow functions:

P.then(data => doWork('text', data));

I find this most readable, and not too much to write.

You can use Function.prototype.bind to create a new function with a value passed to its first argument, like this

P.then(doWork.bind(null, 'text'))

and you can change doWork to,

function doWork(text, data) {
  consoleToLog(data);
}

Now, text will be actually 'text' in doWork and data will be the value resolved by the Promise.

Note: Please make sure that you attach a rejection handler to your promise chain.

Working program: Live copy on Babel's REPL

function doWork(text, data) {
  console.log(text + data + text);
}

new Promise(function (resolve, reject) {
    var a = 5;
    if (a) {
      setTimeout(function () {
        resolve(a);
      }, 3000);
    } else {
      reject(a);
    }
  })
  .then(doWork.bind(null, 'text'))
  .catch(console.error);

Use currying.

var P = new Promise(function (resolve, reject) {
    var a = 5;
    if (a) {
        setTimeout(function(){
            resolve(a);
        }, 3000);
    } else {
        reject(a);
    }
});

var curriedDoWork = function(text) {
    return function(data) {
        console.log(data + text);
    }
};

P.then(curriedDoWork('text'))
.catch(
    //some error handling
);