Error: Cannot promisify an API that has normal methods

Error: Cannot promisify an API that has normal methods

This error indicates you have tried to call Promise.promisifyAll on an object that already has a property with the Async suffix:

var myApi = { foo: function(cb){ ... }, fooAsync(cb) { ... }

This is because Bluebird adds the Async suffix to distinguish the original method from the promisified one, so fooAsync would have been overridden. In order to avoid this - either rename fooAsync before promisifying the API, or call Promise.promisify manually on select properties.

If you find this issue in a common library please open an issue