View Source Commanded.Assertions.EventAssertions (Commanded v1.4.3)

Provides test assertion and wait for event functions to help test applications built using Commanded.

The default assert and refute receive timeouts are one second.

You can override the default timeout in config (e.g. config/test.exs):

config :commanded,
  assert_receive_event_timeout: 1_000,
  refute_receive_event_timeout: 1_000

Summary

Functions

Assert that events matching their respective predicates have a matching correlation id.

assert_receive_event(application, event_type, assertion_fn)

Assert that an event of the given event type is published. Verify that event using the assertion function.

assert_receive_event(application, event_type, predicate_fn, assertion_fn)

Assert that an event of the given event type, matching the predicate, is published. Verify that event using the assertion function.

refute_receive_event(application, event_type, refute_fn, opts \\ [])

Refute that an event of the given type has been received.

wait_for_event(application, event_type)

Wait for an event of the given event type to be published.

wait_for_event(application, event_type, predicate_fn)

Wait for an event of the given event type, matching the predicate, to be published.

Functions

assert_correlated(application, event_type_a, predicate_a, event_type_b, predicate_b)

Assert that events matching their respective predicates have a matching correlation id.

Useful when there is a chain of events that is connected through event handlers.

Example

assert_correlated(
  BankApp,
  BankAccountOpened, fn opened -> opened.id == 1 end,
  InitialAmountDeposited, fn deposited -> deposited.id == 2 end
)

assert_receive_event(application, event_type, assertion_fn)

Assert that an event of the given event type is published. Verify that event using the assertion function.

Example

assert_receive_event(BankApp, BankAccountOpened, fn opened ->
  assert opened.account_number == "ACC123"
end)

assert_receive_event(application, event_type, predicate_fn, assertion_fn)

Assert that an event of the given event type, matching the predicate, is published. Verify that event using the assertion function.

Example

assert_receive_event(BankApp, BankAccountOpened,
  fn opened -> opened.account_number == "ACC123" end,
  fn opened ->
    assert opened.balance == 1_000
  end)

refute_receive_event(application, event_type, refute_fn, opts \\ [])

Refute that an event of the given type has been received.

An optional predicate may be provided to filter events matching the refuted type.

Examples

Refute that ExampleEvent is produced by given anonymous function:

refute_receive_event(ExampleApp, ExampleEvent, fn ->

:ok = MyApp.dispatch(command)

end)

Refute that ExampleEvent is produced by some_func/0 function:

refute_receive_event(ExampleApp, ExampleEvent, &some_func/0)

Refute that ExampleEvent matching given event_matches?/1 predicate function is produced by some_func/0 function:

refute_receive_event(ExampleApp, ExampleEvent, &some_func/0,
  predicate: &event_matches?/1
)

Refute that ExampleEvent matching given anonymous predicate function is produced by some_func/0 function:

refute_receive_event(ExampleApp, ExampleEvent, &some_func/0,
  predicate: fn event -> event.value == 1 end
)

Refute that ExampleEvent produced by some_func/0 function is published to a given stream:

refute_receive_event(ExampleApp, ExampleEvent, &some_func/0,
  predicate: fn event -> event.value == 1 end,
  stream: "foo-1234"
)

wait_for_event(application, event_type)

Wait for an event of the given event type to be published.

Examples

wait_for_event(BankApp, BankAccountOpened)

wait_for_event(application, event_type, predicate_fn)

Wait for an event of the given event type, matching the predicate, to be published.

Examples

wait_for_event(BankApp, BankAccountOpened, fn opened ->
  opened.account_number == "ACC123"
end)