Newbie’s information to server-side Swift utilizing the Hummingbird framework

Swift on the Server in 2023

Three years in the past I began to concentrate on Vapor, the most well-liked web-framework written in Swift, which served me very nicely over time, however now it’s time to begin a brand new chapter in my life.

As I realized increasingly more about how servers work I spotted that Vapor has it is personal execs and cons. The neighborhood modified quite a bit throughout the previous 3 years, some core members left and new individuals began to keep up the framework. I additionally had some struggles with the default template engine (Leaf) and lately I began to show away from the summary database layer (Fluent) too. One other ache level for me is the rising variety of dependencies, I barely use websockets & multipart-kit, however Vapor has these dependencies by default and you’ll’t eliminate them. 😢

Vapor has some very nice issues to supply, and for the general public it is nonetheless going to be an excellent selection for constructing backends for frontends (BFFs). For me, Vapor reached its limits and I needed to make use of one thing that feels a bit lighter. Somethings that’s modular, one thing that may be simply prolonged and matches my precise wants with out further (unused) package deal dependencies.

This shiny new factor is named Hummingbird and it seems very promising. It was created by Adam Fowler who’s a member of the SSWG and in addition the principle creator of the Soto library (AWS Swift).

Hummingbird has a complete documentation out there on-line and a pleasant instance repository containing numerous demo apps written utilizing the Hummingbird Swift server framework. I imagine that the very best a part of the the framework is modularity & extensibility. By the way in which, Hummingbird works with out Basis, however it has extensions for Basis objects, it is a large plus for me, however perhaps that is simply my private desire these days. Hummingbird could be prolonged simply, yow will discover some very helpful extensions below the Hummingbird mission web page, lengthy story quick it really works with Fluent and it is comparatively simple to get together with it when you’ve got some Vapor information… 🤔

Getting began with Hummingbird

To start with, there is no such thing as a toolbox or command line utility to assist the kickoff course of, however you possibly can all the time obtain the examples repository and use one of many tasks as a place to begin. Alternatively you possibly can set every part up by hand, that is what we will do now. 🔨

With a purpose to construct a brand new utility utilizing the Hummingbird framework it is best to create a brand new listing and initialize a brand new Swift package deal utilizing the next instructions:

mkdir server && cd $_
swift package deal init --type executable
open Bundle.swift

It will create a brand new Swift package deal and open the Bundle.swift file in Xcode. You should utilize your individual editor in the event you don’t love Xcode, however both means you will have so as to add Hummingbird to your package deal manifest file as a dependency. We’ll setup an App goal for the appliance itself, and a Server goal for the principle executable, which can use the appliance and configure it as wanted.

import PackageDescription

let package deal = Bundle(
    identify: "server",
    platforms: [
        .macOS(.v10_15),
    ],
    dependencies: [
        .package(
            url: "https://github.com/hummingbird-project/hummingbird",
            from: "1.0.0"
        ),
        .package(
            url: "https://github.com/apple/swift-argument-parser",
            from: "1.0.0"
        ),
    ],
    targets: [
        .executableTarget(
            name: "Server",
            dependencies: [
                .product(
                    name: "ArgumentParser",
                    package: "swift-argument-parser"
                ),
                .target(name: "App"),
            ]
        ),
        .goal(
            identify: "App",
            dependencies: [
                .product(
                    name: "Hummingbird",
                    package: "hummingbird"
                ),
                .product(
                    name: "HummingbirdFoundation",
                    package: "hummingbird"
                ),
            ],
            swiftSettings: [
                .unsafeFlags(
                    ["-cross-module-optimization"],
                    .when(configuration: .launch)
                ),
            ]
        ),
        .testTarget(
            identify: "AppTests",
            dependencies: [
                .product(
                    name: "HummingbirdXCT",
                    package: "hummingbird"
                ),
                .target(name: "App"),
            ]
        ),
    ]
)

Please create the required file and listing construction, as listed under, earlier than you proceed to the following steps. It is rather essential to call issues as they seem, in any other case SPM will not work and the mission will not compile. Anyway, the mission construction is kind-of Vapor-like as you possibly can see. 💧

.
├── Bundle.resolved
├── Bundle.swift
├── README.md
├── Sources
│ ├── App
│ │ └── HBApplication+Configure.swift
│ └── Server
│     └── essential.swift
└── Assessments
    └── AppTests
        └── AppTests.swift

The following step is to create the principle entry level for the appliance. For this objective Hummingbird makes use of the Swift Argument Parser library. Place the next contents into the principle.swift file:

import ArgumentParser
import Hummingbird
import App

struct HummingbirdCommand: ParsableCommand {

    @Possibility(identify: .shortAndLong)
    var hostname: String = "127.0.0.1"

    @Possibility(identify: .shortAndLong)
    var port: Int = 8080

    func run() throws {
        let app = HBApplication(
            configuration: .init(
                tackle: .hostname(hostname, port: port),
                serverName: "Hummingbird"
            )
        )
        strive app.configure()
        strive app.begin()
        app.wait()
    }
}

HummingbirdCommand.essential()

The HummingbirdCommand has two choices, you possibly can setup a customized hostname and port by offering these values as command line choices (I am going to present it afterward), the appliance itself will setup the tackle utilizing the enter after which it will begin listening on the required port.

The configure technique comes from the App goal, that is the place you possibly can customise your server occasion, register route handlers and stuff like that, identical to you’ll do that in Vapor. The principle distinction is that Hummingbird makes use of the HB namespace, which is fairly useful, and the configure technique is written as an extension. Let’s write it and register a primary route handler. 🧩

import Hummingbird
import HummingbirdFoundation

public extension HBApplication {

    func configure() throws {

        router.get("/") { _ in
            "Good day, world!"
        }
    }
}

That is it. Now it is best to be capable of run your server, you possibly can press the Play button in Xcode that’ll begin your utility or enter one of many following instructions into the Terminal utility:

# simply run the server
swift run Server

# customized hostname and port
swift run Server --port 3000
swift run Server --hostname 0.0.0.0 --port 3000

# quick model
swift run Server -p 3000
swift run Server -h 0.0.0.0 -p 3000

# set the log degree (https://github.com/apple/swift-log#log-levels)
LOG_LEVEL=discover swift run Server -p 3000

# make launch construct
swift construct -c launch

# copy launch construct to the native folder
cp .construct/launch/Server ./Server

# run the executable
LOG_LEVEL=discover ./Server -p 3000

You may set these values in Xcode too, simply click on on the server scheme and choose the Edit Scheme… menu merchandise. Just remember to’re on the Run goal, displaying the Arguments tag. Merely provde the Arguments Handed On Launch choices to set a customized hostname or port and you’ll set the log degree by including a brand new merchandise into the Surroundings Variables part.

If you would like to unit check your utility, I’ve obtained a excellent news for you. Hummingbird additionally comes with a pleasant utility software referred to as HummingbirdXCT, which you’ll simply setup & use if you would like to run some assessments towards your API. In our mission, merely alter the AppTests.swift file.

import Hummingbird
import HummingbirdXCT
import XCTest
@testable import App

last class AppTests: XCTestCase {
    
    func testHelloWorld() throws {
        let app = HBApplication(testing: .dwell)
        strive app.configure()

        strive app.XCTStart()
        defer { app.XCTStop() }

        strive app.XCTExecute(uri: "/", technique: .GET) { response in
            XCTAssertEqual(response.standing, .okay)

            let expectation = "Good day, world!"
            let res = response.physique.map { String(buffer: $0) }
            XCTAssertEqual(res, expectation)
        }
    }
}

As an alternative of making the appliance from the principle entry level, we are able to arrange a brand new HBApplication occasion, import the App framework and name the configure technique on it. the XCT framework comes with a customized XCTStart and XCTStop technique, and you’ll execute HTTP requests utilizing the XCTExecute perform. The response is on the market in a completion block and it is attainable to look at the standing code and extract the physique utilizing a handy String initializer.

As you possibly can see Hummingbird is kind of much like Vapor, however it’s light-weight and you’ll nonetheless add these additional issues to your server when it’s wanted. Hummingbird looks like the following iteration of Vapor. I actually do not know if Vapor 5, goes to repair the problems I am at the moment having with the framework or not, however I do not actually care, as a result of that launch will not occur anytime quickly.