Expect-promise - expect package plugin for promises

The package expect-promise is a plugin to expect which adds words used to manage promises.

Installation

You can install expect-promise using LuaRocks with the command:

luarocks install expect-promise

Compatibility

The plugin is tested against the promise-lua, but it may be usable with any module providing promises, as far as it respects the A+ specification (no matter how the then function is actually called), and the promise object has a modifiable metatable.

Configuration

In order to use the plugin, you must declare it somewhere in your tests. A good place for this is a file always read before executing the tests. For that, simply require the module, providing the expect object as parameter.

By default, the plugin expects your promise to have a next method behaving like the then method of the promise A+ specification. If this is not the case, you must provide the name of the function to the configuration option expect.parameters.promise.next.

local expect = require('expect')
require('expect-promise')(expect)
expect.parameters.promise = {
  next = 'thenCall'
}

Usage

eventually

Resolves the promise, replaces the target object with the result, and continues the assertion chain.

expect(Promise.resolve(42)).to.eventually.be.a('number').that.equals(42)

fulfilled()

Asserts that the target promise is fulfilled.

expect(Promise.resolve(42)).to.be.fulfilled()

rejected()

Asserts that the target promise is rejected.

expect(Promise.reject()).to.be.rejected()

rejectedWith(err[, plain])

Asserts that the target promise is rejected with the given error err. If this argument is of type string, the test is made using LUA function find and a second boolean argument can be provided in order to consider the err as a plain string instead of a LUA pattern.

expect(Promise.reject('nooo')).to.be.rejectedWith('n.*o$')
expect(Promise.reject('nooo')).to.be.rejectedWith('no', true)