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 deal with Vapor, the preferred web-framework written in Swift, which served me very effectively through the years, however now it’s time to begin a brand new chapter in my life.

As I realized increasingly more about how servers work I noticed that Vapor has it is personal execs and cons. The neighborhood modified loads in the course of the previous 3 years, some core members left and new folks 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 may’t do away with them. ?

Vapor has some very nice issues to supply, and for most people it is nonetheless going to be a fantastic alternative for constructing backends for frontends (BFFs). For me, Vapor reached its limits and I wished to make use of one thing that feels a bit lighter. Somethings that’s modular, one thing that may be simply prolonged and suits my actual wants with out extra (unused) bundle dependencies.

This shiny new factor known as Hummingbird and it seems to be very promising. It was created by Adam Fowler who’s a member of the SSWG and likewise the principle creator of the Soto library (AWS Swift).

Hummingbird has a complete documentation accessible on-line and a pleasant instance repository containing varied demo apps written utilizing the Hummingbird Swift server framework. I imagine that the perfect 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 big plus for me, however perhaps that is simply my private choice these days. Hummingbird might be prolonged simply, you’ll find some very helpful extensions below the Hummingbird mission web page, lengthy story brief it really works with Fluent and it is comparatively straightforward to get together with it if in case you have some Vapor data… ?

Getting began with Hummingbird

Initially, there isn’t a toolbox or command line utility to assist the kickoff course of, however you’ll be able to at all times obtain the examples repository and use one of many tasks as a place to begin. Alternatively you’ll be able to set all the pieces up by hand, that is what we’ll do now. ?

So as to construct a brand new software utilizing the Hummingbird framework you must create a brand new listing and initialize a brand new Swift bundle utilizing the next instructions:

mkdir server && cd $_
swift bundle init --type executable
open Package deal.swift

It will create a brand new Swift bundle and open the Package deal.swift file in Xcode. You should utilize your personal editor when you do not like Xcode, however both manner you may have so as to add Hummingbird to your bundle manifest file as a dependency. We will 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 bundle = Package deal(
    title: "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(
            title: "App",
            dependencies: [
                .product(
                    name: "Hummingbird",
                    package: "hummingbird"
                ),
                .product(
                    name: "HummingbirdFoundation",
                    package: "hummingbird"
                ),
            ],
            swiftSettings: [
                .unsafeFlags(
                    ["-cross-module-optimization"],
                    .when(configuration: .launch)
                ),
            ]
        ),
        .testTarget(
            title: "AppTests",
            dependencies: [
                .product(
                    name: "HummingbirdXCT",
                    package: "hummingbird"
                ),
                .target(name: "App"),
            ]
        ),
    ]
)

Please create the mandatory file and listing construction, as listed beneath, earlier than you proceed to the subsequent steps. It is vitally necessary 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’ll be able to see. ?

.
??? Package deal.resolved
??? Package deal.swift
??? README.md
??? Sources
? ??? App
? ? ??? HBApplication+Configure.swift
? ??? Server
?     ??? foremost.swift
??? Exams
    ??? AppTests
        ??? AppTests.swift

The subsequent step is to create the principle entry level for the appliance. For this function 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 {

    @Choice(title: .shortAndLong)
    var hostname: String = "127.0.0.1"

    @Choice(title: .shortAndLong)
    var port: Int = 8080

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

HummingbirdCommand.foremost()

The HummingbirdCommand has two choices, you’ll be able to setup a customized hostname and port by offering these values as command line choices (I will present it afterward), the appliance itself will setup the handle utilizing the enter after which it will begin listening on the desired port.

The configure methodology comes from the App goal, that is the place you’ll be able to customise your server occasion, register route handlers and stuff like that, similar to you’d do that in Vapor. The principle distinction is that Hummingbird makes use of the HB namespace, which is fairly helpful, and the configure methodology is written as an extension. Let’s write it and register a fundamental route handler. ?

import Hummingbird
import HummingbirdFoundation

public extension HBApplication {

    func configure() throws {

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

That is it. Now you must have the ability to run your server, you’ll be able to press the Play button in Xcode that’ll begin your software or enter one of many following instructions into the Terminal software:

# 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

# brief 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 possibly can set these values in Xcode too, simply click on on the server scheme and choose the Edit Scheme… menu merchandise. Just be sure you’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 may set the log degree by including a brand new merchandise into the Setting Variables part.

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

import Hummingbird
import HummingbirdXCT
import XCTest
@testable import App

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

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

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

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

As a substitute 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 methodology on it. the XCT framework comes with a customized XCTStart and XCTStop methodology, and you may execute HTTP requests utilizing the XCTExecute perform. The response is on the market in a completion block and it is doable to look at the standing code and extract the physique utilizing a handy String initializer.

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