assert.md

Assert API

Overview

There is a public API to facilitate writing unit tests while using RxGo. This is based on rxgo.Assert. It automatically creates an Observer on an Iterable (Observable, Single or OptionalSingle).

func TestMap(t *testing.T) {
	err := errors.New("foo")
	observable := rxgo.Just(1, 2, 3)().
		Map(func(_ context.Context, i interface{}) (interface{}, error) {
			if i == 3 {
				return nil, err
			}
			return i, nil
		})

	rxgo.Assert(context.Background(), t, observable,
		rxgo.HasItems(1, 2),
		rxgo.HasError(err))
}

=== RUN   TestMap
--- PASS: TestMap (0.00s)
PASS

Predicates

The API accepts the following list of predicates:

HasItems

Check whether an Observable produced a given list of items.

rxgo.Assert(ctx, t, observable, rxgo.HasItems(1, 2, 3))

HasItem

Check whether an Single or OptionalSingle produced a given item.

rxgo.Assert(ctx, t, single, rxgo.HasItem(1))

HasItemsNoOrder

Check whether an Observable produced a given item regardless of the ordering (useful when we use a pool option)

rxgo.Assert(ctx, t, single, rxgo.HasItemsNoOrder(1, 2, 3))

IsEmpty

Check whether an Iterable produced no item(s).

rxgo.Assert(ctx, t, single, rxgo.IsEmpty())

IsNotEmpty

Check whether an Iterable produced any item(s).

rxgo.Assert(ctx, t, single, rxgo.IsNotEmpty())

HasError

Check whether an Iterable produced a given error.

rxgo.Assert(ctx, t, single, rxgo.HasError(expectedErr))

HasAnError

Check whether an Iterable produced an error.

rxgo.Assert(ctx, t, single, rxgo.HasAnError())

HasErrors

Check whether an Iterable produced a given list of errors (useful when we use rxgo.ContinueOnError strategy).

rxgo.Assert(ctx, t, single, rxgo.HasErrors(expectedErr1, expectedErr2, expectedErr3))

HasNoError

Check whether an Iterable did not produced any error.

rxgo.Assert(ctx, t, single, rxgo.HasNoError())

CustomPredicate

Implement a custom predicate.

rxgo.Assert(ctx, t, observable, rxgo.CustomPredicate(func(items []interface{}) error {
	if len(items) != 3 {
		return errors.New("wrong number of items")
	}
	return nil
}))