stream_test_subscriber

stream_test_subscriber is a Dart package that simplifies testing streams by providing a straightforward API for subscribing to and asserting values from a stream. It allows you to easily collect emitted values, verify their sequence, and handle asynchronous stream events in tests. Ideal for unit testing stream-based code with minimal boilerplate.

Features

Easy Subscription: Subscribes to a stream and collects emitted values for testing.
Value Assertions: Assert that the stream has emitted a specific sequence of values.
Empty Stream Check: Verify that no values have been emitted by the stream.
Resource Cleanup: Automatically cancels the internal subscription after assertions to prevent resource leaks.

Getting started

Prerequisites

To use stream_test_subscriber, ensure you have the following:

Dart SDK 2.12.0 or later.
A Flutter or Dart project.

Installation

Add stream_test_subscriber to your pubspec.yaml:

dependencies:
  stream_test_subscriber: ^1.0.0

Then, run flutter pub get to install the package.

Usage

Basic Setup

Here's a basic example of how to use stream_test_subscriber to subscribe to and assert values from a stream in a test:

void main() {
  test(
    "should emit values that has been collected from the stream",
        () async {
      final controller = StreamController<int>();
      final subscriber = controller.stream.test();

      for (var value in [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]) {
        controller.add(value);
      }

      await subscriber.expectValues([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
    },
  );
}