Swift 유닛테스트 환경 쉽게 만들기

Posted at — Aug 17, 2021

Swift 로 UnitTest 작성 환경이 필요할 때, 가장 빠른 방법이 무엇일까? 코딩테스트나 간단한 알고리즘 구현시에 유닛테스트를 만들어 진행하면 편리한데, IDE를 실행하여 프로젝트를 만들거나 플레이그라운드를 만드는 것은 뭔가 번잡하게 느껴졌다.

Swift Package Manager

Swift Package Manager를 사용하면 쉽게 UnitTest 환경을 만들 수 있다. 아래처럼 테스팅을 위한 폴더를 만든 다음 Swift Package 로 초기화한다.

$ mkdir collection-test
$ cd collection-test
$ swift package init

Creating library package: collection-test
Creating Package.swift
Creating README.md
Creating .gitignore
Creating Sources/
Creating Sources/collection-test/collection_test.swift
Creating Tests/
Creating Tests/collection-testTests/
Creating Tests/collection-testTests/collection_testTests.swift

테스트 실행

Swift Package로 초기화를 하면 테스트가 이미 만들어져 있다. 아래와 같이 만들어진 테스트를 실험할 수 있다.

$ swift test

[5/5] Linking collection-testPackageTests

* Build Completed!
Test Suite 'All tests' started at 2021-08-17 23:36:38.860
Test Suite 'collection-testPackageTests.xctest' started at 2021-08-17 23:36:38.861
Test Suite 'collection_testTests' started at 2021-08-17 23:36:38.861
Test Case '-[collection_testTests.collection_testTests testExample]' started.
Test Case '-[collection_testTests.collection_testTests testExample]' passed (0.003 seconds).
Test Suite 'collection_testTests' passed at 2021-08-17 23:36:38.864.
	 Executed 1 test, with 0 failures (0 unexpected) in 0.003 (0.003) seconds
Test Suite 'collection-testPackageTests.xctest' passed at 2021-08-17 23:36:38.864.
	 Executed 1 test, with 0 failures (0 unexpected) in 0.003 (0.003) seconds
Test Suite 'All tests' passed at 2021-08-17 23:36:38.864.
	 Executed 1 test, with 0 failures (0 unexpected) in 0.003 (0.004) seconds

패키지 폴더 구조

Swift Package Manager가 초기화한 패키지 폴더 구조는 아래와 같다.

.
├── Package.swift
├── README.md
├── Sources
│   └── collection-test
│       └── collection_test.swift
└── Tests
    └── collection-testTests
        └── collection_testTests.swift

iOS 관련 유닛테스트

만약, 디펜던시로 iOS 용 라이브러리를 사용한다면 테스트를 iOS 개발 환경에서 실행해야 한다. 이를 위해서 스킴과 개발 플랫폼을 설정하여 테스트를 실행할 수 있다. 이 때는 swift 대신에 xcodebuild를 사용한다.

Scheme 목록 확인

$ xcodebuild -list

Command line invocation:
    /Applications/Xcode.app/Contents/Developer/usr/bin/xcodebuild -list

User defaults from command line:
    IDEPackageSupportUseBuiltinSCM = YES

Resolve Package Graph

Resolved source packages:
  collection-test: /Users/burt/github/temp/collection-test

Information about workspace "collection-test":
    Schemes:
        collection-test

collection-test 스킴을 확인할 수 있다.

iOS 개발 플랫폼에서 테스트 실행하기

$ xcodebuild -scheme collection-test test -sdk iphonesimulator -destination 'platform=iOS Simulator,name=iPhone 12'

Command line invocation:
    /Applications/Xcode.app/Contents/Developer/usr/bin/xcodebuild -scheme collection-test test -sdk iphonesimulator -destination "platform=iOS Simulator,name=iPhone 12"

User defaults from command line:
    IDEPackageSupportUseBuiltinSCM = YES

Build settings from command line:
    SDKROOT = iphonesimulator14.5

Resolve Package Graph

Resolved source packages:
  collection-test: /Users/burt/github/temp/collection-test

...

Testing started
Test Suite 'All tests' started at 2021-08-17 23:43:15.537
Test Suite 'collection-testTests.xctest' started at 2021-08-17 23:43:15.538
Test Suite 'collection_testTests' started at 2021-08-17 23:43:15.538
Test Case '-[collection_testTests.collection_testTests testExample]' started.
Test Case '-[collection_testTests.collection_testTests testExample]' passed (0.002 seconds).
Test Suite 'collection_testTests' passed at 2021-08-17 23:43:15.541.
	 Executed 1 test, with 0 failures (0 unexpected) in 0.002 (0.003) seconds
Test Suite 'collection-testTests.xctest' passed at 2021-08-17 23:43:15.541.
	 Executed 1 test, with 0 failures (0 unexpected) in 0.002 (0.003) seconds
Test Suite 'All tests' passed at 2021-08-17 23:43:15.542.
	 Executed 1 test, with 0 failures (0 unexpected) in 0.002 (0.004) seconds
2021-08-17 23:43:15.808 xcodebuild[21690:392957] [MT] IDETestOperationsObserverDebug: 7.114 elapsed -- Testing started completed.
2021-08-17 23:43:15.808 xcodebuild[21690:392957] [MT] IDETestOperationsObserverDebug: 0.000 sec, +0.000 sec -- start
2021-08-17 23:43:15.808 xcodebuild[21690:392957] [MT] IDETestOperationsObserverDebug: 7.114 sec, +7.114 sec -- end

Test session results, code coverage, and logs:
	/Users/burt/Library/Developer/Xcode/DerivedData/collection-test-ghhizvljwobqsmcyznxghxnvhbyv/Logs/Test/Test-collection-test-2021.08.17_23-43-05-+0900.xcresult

** TEST SUCCEEDED **

디펜던시 추가하기

Package.swift 파일을 열고 dependencies 에 원하는 디펜던시를 추가한다. 이 글에서는 애플의 swift-collections 라이브러리를 설치해 본다.

// swift-tools-version:5.3
// The swift-tools-version declares the minimum version of Swift required to build this package.

import PackageDescription

let package = Package(
    name: "collection-test",
    products: [
        // Products define the executables and libraries a package produces, and make them visible to other packages.
        .library(
            name: "collection-test",
            targets: ["collection-test"]),
    ],
    dependencies: [
        // Dependencies declare other packages that this package depends on.
        .package(url: "https://github.com/apple/swift-collections.git", from: "0.0.5"),
    ],
    targets: [
        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
        // Targets can depend on other targets in this package, and on products in packages this package depends on.
        .target(
            name: "collection-test",
            dependencies: []),
        .testTarget(
            name: "collection-testTests",
            dependencies: [
                "collection-test",
                // 중요!
                .product(name: "Collections", package: "swift-collections")
            ]),
    ]
)

.testTarget 에 .product 로 명확하게 swift-collections를 선언해 주는 것이 중요하다. 이렇게 하지 않으면 test타겟에서 swift-collections를 찾을 수 없다.. 디펜던시를 추가하고 swift build 또는 swift test를 실행하여 디펜던시를 설치한다.

$ swift test

Fetching https://github.com/apple/swift-collections
Cloning https://github.com/apple/swift-collections
Resolving https://github.com/apple/swift-collections at 0.0.5
warning: dependency 'swift-collections' is not used by any target
[1/1] Planning build

* Build Completed!Test Suite 'All tests' started at 2021-08-17 23:49:32.667
Test Suite 'collection-testPackageTests.xctest' started at 2021-08-17 23:49:32.668
Test Suite 'collection_testTests' started at 2021-08-17 23:49:32.668
Test Case '-[collection_testTests.collection_testTests testExample]' started.
Test Case '-[collection_testTests.collection_testTests testExample]' passed (0.004 seconds).
Test Suite 'collection_testTests' passed at 2021-08-17 23:49:32.673.
	 Executed 1 test, with 0 failures (0 unexpected) in 0.004 (0.005) seconds
Test Suite 'collection-testPackageTests.xctest' passed at 2021-08-17 23:49:32.673.
	 Executed 1 test, with 0 failures (0 unexpected) in 0.004 (0.005) seconds
Test Suite 'All tests' passed at 2021-08-17 23:49:32.673.
	 Executed 1 test, with 0 failures (0 unexpected) in 0.004 (0.005) seconds

테스트 작성하기

방금 설치한 swift-collections를 테스트해 보자. 이미 만들어진 테스트 파일 중에 collection_testTests.swift 파일을 열고 아래와 같이 테스트를 작성한다.

import XCTest
@testable import collection_test
import Collections

final class collection_testTests: XCTestCase {
    func testExample() {
        // This is an example of a functional test case.
        // Use XCTAssert and related functions to verify your tests produce the correct
        // results.
        XCTAssertEqual(collection_test().text, "Hello, World!")
    }

    func testDeque() {
        var deque: Deque<String> = ["Ted", "Rebecca"]
        deque.prepend("Keeley")
        deque.append("Nathan")
        XCTAssertEqual(deque, ["Keeley", "Ted", "Rebecca", "Nathan"])
        XCTAssertEqual(deque.popLast(), "Nathan")
        XCTAssertEqual(deque[1], "Ted")
        XCTAssertEqual(deque.count, 3)

        deque.remove(at: 1)
        XCTAssertEqual(deque.count, 2)
    }
}

테스트 실행

작성한 테스트를 실행한다.

$ swift test

[3/3] Linking collection-testPackageTests

* Build Completed!
Test Suite 'All tests' started at 2021-08-18 00:20:07.819
Test Suite 'collection-testPackageTests.xctest' started at 2021-08-18 00:20:07.820
Test Suite 'collection_testTests' started at 2021-08-18 00:20:07.820
Test Case '-[collection_testTests.collection_testTests testDeque]' started.
Test Case '-[collection_testTests.collection_testTests testDeque]' passed (0.002 seconds).
Test Case '-[collection_testTests.collection_testTests testExample]' started.
Test Case '-[collection_testTests.collection_testTests testExample]' passed (0.000 seconds).
Test Suite 'collection_testTests' passed at 2021-08-18 00:20:07.822.
	 Executed 2 tests, with 0 failures (0 unexpected) in 0.003 (0.003) seconds
Test Suite 'collection-testPackageTests.xctest' passed at 2021-08-18 00:20:07.822.
	 Executed 2 tests, with 0 failures (0 unexpected) in 0.003 (0.003) seconds
Test Suite 'All tests' passed at 2021-08-18 00:20:07.822.
	 Executed 2 tests, with 0 failures (0 unexpected) in 0.003 (0.003) seconds

테스트가 잘 실행 됨을 확인할 수 있다.

Burt.K

Awesome Discovery

Swift 유닛테스트 환경 쉽게 만들기

Table of Contents

Swift Package Manager

테스트 실행

패키지 폴더 구조

iOS 관련 유닛테스트

Scheme 목록 확인

iOS 개발 플랫폼에서 테스트 실행하기

디펜던시 추가하기

테스트 작성하기

테스트 실행