Jasmine promise-returning spec wrapper function, example with https://github.com/slightlyoff/Promises

example.js

describe("Something", function () {
  it("should promise", promising(function () {
    return Promise.reject("Ouch!");
  }));
});

promising.js

function promising(fun, message, timeout) {
  return function () {
    var spec = jasmine.getEnv().currentSpec;
    var completed = false;

    runs(function () {
      var result = fun();
      if (typeof result === 'undefined') {
        completed = true;
      } else if (typeof result !== 'object' || typeof result.then !== 'function') {
        spec.fail(new Error("`it(promising)` block returns non-promise: " + result));
        completed = true;
      } else {
        try {
          result.then(function (value) {
            if (typeof value !== 'undefined') {
              spec.fail(new Error("Promise fulfilled with unexpected value: " + value));
            }
            completed = true;
          }, function (error) {
            spec.fail(error);
            completed = true;
          });
        } catch (error) {
          spec.fail(error);
          completed = true;
        }
      }
    });

    waitsFor(function () {
      return completed;
    }, message, timeout);
  };
};