Java Output Tracking for Testing without Mocks

Java implementation of James Shore's output tracking method for Nullables and Testing without mocks approach.

Description

output-tracking is a lightweight library designed to facilitate testing without relying on mocking frameworks. It provides tools to track and verify outputs produced by testable components, enabling clean and maintainable tests.

Installation

To include output-tracking in your project, add the following dependency to your pom.xml if you're using Maven:

<dependency>
    <groupId>com.example</groupId>
    <artifactId>output-tracking</artifactId>
    <version>1.0.0</version>
</dependency>

For Gradle, add this to your build.gradle:

implementation 'com.example:output-tracking:1.0.0'

Usage

Tracking Outputs

The library allows you to track outputs produced by your components. You can read the tests to get an idea of how to use the library, but here's a simple example:

import ewc.utilities.testableio.tracking.OutputListener;
import ewc.utilities.testableio.tracking.OutputTracker;

public class Example {
    public static void main(String[] args) {
        OutputListener<String> listener = new OutputListener<>();
        OutputTracker<String> tracker = listener.trackOutput();

        // Simulate producing outputs
        listener.track("Hello");
        listener.track("World");

        // Retrieve tracked outputs
        System.out.println(tracker.data()); // Output: [Hello, World]

        // Clear tracked outputs
        tracker.clear();
        System.out.println(tracker.data()); // Output: []
    }
}

Stopping Tracking

You can stop tracking outputs and remove the tracker from the listener:

OutputListener<String> listener = new OutputListener<>();
OutputTracker<String> tracker = listener.trackOutput();

public class Example {
    public static void main(String[] args) {
        listener.track("Test Output");
        System.out.println(tracker.data()); // Output: [Test Output]

        // Stop tracking
        tracker.stopTracking();
        System.out.println(listener.trackers().isEmpty()); // Output: true

        listener.track("Another Output"); // This won't be tracked anywhere
    }
}

Features

• Enable testable components to produce some output describing their state and behavior. Think of it as a logging mechanism that stores any kind of objects, so you can then test the sequence of logged events and the data they contain.
• Retrieve and clear tracked outputs.
• Manage multiple trackers with a single listener.

License

This project is licensed under the MIT License. See the LICENSE file for details.