.timeout

.timeout(
    int ms,
    [String message="operation timed out"]
) -> Promise

.timeout(
    int ms,
    [Error error]
) -> Promise

Returns a promise that will be fulfilled with this promise's fulfillment value or rejection reason. However, if this promise is not fulfilled or rejected within ms milliseconds, the returned promise is rejected with a TimeoutError or the error as the reason.

When using the first signature, you may specify a custom error message with the message parameter.

var Promise = require("bluebird");
var fs = Promise.promisifyAll(require('fs'));
fs.readFileAsync("huge-file.txt").timeout(100).then(function(fileContents) {

}).catch(Promise.TimeoutError, function(e) {
    console.log("could not read file within 100ms");
});