Ussd.Test (Ussd v0.2.0)

A fluent helper for exercising a USSD flow end-to-end in ExUnit tests, mirroring a caller dialing in and replying screen by screen.

import Ussd.Test

test "buying airtime" do
  build(MyApp.States.Welcome)
  |> start()
  |> assert_see("Welcome")
  |> input("1")
  |> assert_see("Enter amount")
  |> input("5")
  |> assert_terminated()
end

assert_see/2 and assert_terminated/1 work against the default test response (a {message, terminating?} tuple) or against a configured use_response/2 whose result looks like %{message: ..., terminating: ...}. Anything else is matched against its inspect/1'd form, which still substring-matches for assert_see/2 but leaves the terminating flag unknown - prefer the default response unless you're specifically testing a Ussd.Response formatter.

Each acting_as/2 name gets its own session id and its own remembered screen, so switching between callers and back doesn't lose or mix up either one's state.

Summary

Types

t()

Functions

acting_as(test, actor)

Switches which simulated caller is dialing in. Assertions and input/2 after this apply to actor. The first time a given name is used it dials in fresh (like start/2); switching back to a name used before restores exactly what that caller last saw, with no re-dispatch.

additional(test, bag)

Sets the extra Ussd.Context bag values every dispatch in this session sees.

assert_context_has(test, key, expectation \\ nil)

Asserts key is present in the Ussd.Context bag from the last dispatch. With no expectation, just asserts it's non-nil; pass a value to compare equality, or a 1-arity function to assert a predicate against it.

assert_context_missing(test, key)

Asserts key is absent (or nil) in the Ussd.Context bag from the last dispatch.

assert_not_terminated(test)

Asserts the session is still awaiting input after the last dispatch.

assert_record_has(test, key, expectation \\ nil)

Asserts key is set on the current actor's Ussd.Record. See assert_context_has/3 for expectation.

assert_record_missing(test, key)

Asserts key is unset on the current actor's Ussd.Record.

assert_see(test, expected)

Asserts the current screen's message contains expected. Returns test unchanged so it chains.

assert_terminated(test)

Asserts the session ended on the last dispatch.

build(initial_state)

Starts configuring a test session for initial_state.

input(test, input)

Replies with input, as if the caller typed it and pressed send.

start(test, input \\ "")

Dials in for the first time, optionally with an initial input (e.g. a shortcode).

timeout(test, ttl_seconds, input \\ "")

Simulates the current actor redialing after a dropped call: sleeps for ttl_seconds (plus a small buffer, so a continuing_ttl of a matching or shorter duration actually expires), then dispatches input under a brand-new session id for the same caller - the same thing a real "new dial, same phone number" looks like to Ussd.use_continuing_state/4. Keep TTLs short in tests - this really sleeps the test process.

use_configurator(test, configurator)

Applies a Ussd.Configurator to every dispatch in this test session.

use_continuing_state(test, mode, ttl \\ nil, continuing_state \\ nil)

Configures resumable-session behavior for this test session - see Ussd.use_continuing_state/4.

use_exception_handler(test, handler)

Overrides the exception handler under test.

use_response(test, response)

Overrides the response formatter under test, instead of the DSL's own default {message, terminating?} tuple.

use_store(test, store)

Overrides which Ussd.Cache implementation this test session's Ussd.Record calls use.