🕵 NetworkSpyKit

NetworkSpyKit is a lightweight, thread-safe HTTP spy and stub tool for testing code that performs network requests in Swift.

It allows you to:

• Record outgoing URLRequests
• Return predefined or dynamic stubbed responses
• Assert request behavior without hitting the real network
• Keep your tests fast, isolated, and deterministic

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✅ Features

• 🚫 Never touches the real network
• 🧪 Spy on requests (headers, body, URL, method)
• 🎭 Stub custom responses on a per-request basis
• 🧵 Thread-safe and safe for parallel test execution
• ☕ Built-in teapot response for fun (and HTTP 418 awareness)

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🛠 Usage

TODO: generic example from the test cases

import NetworkSpyKit

let spy = NetworkSpy(sessionConfiguration: .default) { request in
    return .success(statusCode: 200,
                    bodyData: #"{"message":"Hello"}"#.data(using: .utf8))
}

let modelController = makeModelController(sessionConfiguration: spy.sessionConfiguration)

// trigger network call
try await modelController.fetchSomething()

XCTAssertEqual(spy.recordedRequests.first?.url.path, "/something")

🧩 Integration

TODO: link to Apple docs of URLSessionConfiguration With any URLSessionConfiguration-based library

1. Inject spy.sessionConfiguration into your networking stack or library.
2. Provide a responseProvider closure to determine what responses should be returned.

Stubbed responses never touch the real network. All requests are intercepted at the protocol layer using a URLProtocol subclass under the hood.

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🧵 Thread Safety

• NetworkSpy uses an internal serial queue to synchronize access.
• You can safely use multiple spies in parallel or across test targets.
• Isolated by using unique headers to associate intercepted requests with the correct NetworkSpy instance.

☕ Teapot Response (Just for Fun)

let spy = NetworkSpy()
spy.responseProvider = { _ in .teaPot() }

Returns:

TODO: better layout for response

Status code: 418
Headers: [:]
Body: { "ERROR": "I'm a teapot" }

Because Hyper Text Coffee Pot Control Protocol is real. Sort of.

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📦 Installation

Swift Package Manager

Add the following to your Package.swift:

.package(url: "https://github.com/yourusername/NetworkSpyKit.git", from: "1.0.0")

Then import it where needed:

import NetworkSpyKit

CocoaPods

Add the following line to your Podfile:

pod 'NetworkSpyKit'

Then run:

pod install

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📄 License

MIT License. See LICENSE for details.