thenlint

A lint for promises that checks for possible Promise.then usage errors.

usage

From the command-line:

thenlint <file.js> [<other.js> ...]

As a library:

report = require('thenlint')(fileContent, filename)
  .map(function(item) { return item.toString(); }).join('\n');

example errors

Suggests ending the promise chain with .done()

// no return or var/assignment
promise.then(function(val) {
  console.log(val);
}); // no errback
// no catch and no .done()

Missing return statement in the middle of a return chain:

promise.then(function(val) {
  // not returning from then
  console.log(val);
  
// but trying to chain another
// call to then/spread
}).then(function(other) {
  // anything
});

non-errors

Adding catch instead of done is okay.

Not returning from within .then is okay as long as we're not trying to chain another .then or .spread

// no return or assignment
promise.then(function(val) {
  // no return...
  console.log(val);
// but has an error handler
// and is not trying to chain a .then/.spread
}).catch(function(err) {
  // anything
}); 

license

MIT