Writing checks utilizing XCTVapor
In my earlier article I confirmed you tips on how to construct a sort secure RESTful API utilizing Vapor. This time we’ll lengthen that mission a bit and write some checks utilizing the Vapor testing instrument to find the underlying points within the API layer. First we’ll use XCTVapor library, then we migrate to a light-weight declarative testing framework (Spec) constructed on high of that.
Earlier than we begin testing our utility, now we have to make it possible for if the app runs in testing mode we register an inMemory database as an alternative of our native SQLite file. We are able to merely alter the configuration and verify the setting and set the db driver primarily based on it.
import Vapor
import Fluent
import FluentSQLiteDriver
public func configure(_ app: Software) throws {
if app.setting == .testing {
app.databases.use(.sqlite(.reminiscence), as: .sqlite, isDefault: true)
}
else {
app.databases.use(.sqlite(.file("Assets/db.sqlite")), as: .sqlite)
}
app.migrations.add(TodoMigration())
strive app.autoMigrate().wait()
strive TodoRouter().boot(routes: app.routes)
}Now we’re able to create our very first unit take a look at utilizing the XCTVapor testing framework. The official docs are quick, however fairly helpful to be taught concerning the fundamentals of testing Vapor endpoints. Sadly it will not inform you a lot about testing web sites or advanced API calls. ✅
We’ll make a easy take a look at that checks the return sort for our Todo checklist endpoint.
@testable import App
import TodoApi
import Fluent
import XCTVapor
ultimate class AppTests: XCTestCase {
func testTodoList() throws {
let app = Software(.testing)
defer { app.shutdown() }
strive configure(app)
strive app.take a look at(.GET, "/todos/", afterResponse: { res in
XCTAssertEqual(res.standing, .okay)
XCTAssertEqual(res.headers.contentType, .json)
_ = strive res.content material.decode(Web page<TodoListObject>.self)
})
}
}As you possibly can see first we setup & configure our utility, then we ship a GET request to the /todos/ endpoint. After now we have a response we will verify the standing code, the content material sort and we will attempt to decode the response physique as a sound paginated todo checklist merchandise object.
This take a look at case was fairly easy, now let’s write a brand new unit take a look at for the todo merchandise creation.
@testable import App
import TodoApi
import Fluent
import XCTVapor
ultimate class AppTests: XCTestCase {
func testCreateTodo() throws {
let app = Software(.testing)
defer { app.shutdown() }
strive configure(app)
let title = "Write a todo tutorial"
strive app.take a look at(.POST, "/todos/", beforeRequest: { req in
let enter = TodoCreateObject(title: title)
strive req.content material.encode(enter)
}, afterResponse: { res in
XCTAssertEqual(res.standing, .created)
let todo = strive res.content material.decode(TodoGetObject.self)
XCTAssertEqual(todo.title, title)
XCTAssertEqual(todo.accomplished, false)
XCTAssertEqual(todo.order, nil)
})
}
}This time we would prefer to submit a brand new TodoCreateObject as a POST information, fortuitously XCTVapor can assist us with the beforeRequest block. We are able to merely encode the enter object as a content material, then within the response handler we will verify the HTTP standing code (it ought to be created) decode the anticipated response object (TodoGetObject) and validate the sector values.
I additionally up to date the TodoCreateObject, because it doesn’t make an excessive amount of sense to have an optionally available Bool discipline and we will use a default nil worth for the customized order. 🤓
public struct TodoCreateObject: Codable {
public let title: String
public let accomplished: Bool
public let order: Int?
public init(title: String, accomplished: Bool = false, order: Int? = nil) {
self.title = title
self.accomplished = accomplished
self.order = order
}
}The take a look at will nonetheless fail, as a result of we’re returning an .okay standing as an alternative of a .created worth. We are able to simply repair this within the create methodology of the TodoController Swift file.
import Vapor
import Fluent
import TodoApi
struct TodoController {
func create(req: Request) throws -> EventLoopFuture<Response> {
let enter = strive req.content material.decode(TodoCreateObject.self)
let todo = TodoModel()
todo.create(enter)
return todo
.create(on: req.db)
.map { todo.mapGet() }
.encodeResponse(standing: .created, for: req)
}
}Now we should always attempt to create an invalid todo merchandise and see what occurs…
func testCreateInvalidTodo() throws {
let app = Software(.testing)
defer { app.shutdown() }
strive configure(app)
let title = ""
strive app.take a look at(.POST, "/todos/", beforeRequest: { req in
let enter = TodoCreateObject(title: title)
strive req.content material.encode(enter)
}, afterResponse: { res in
XCTAssertEqual(res.standing, .created)
let todo = strive res.content material.decode(TodoGetObject.self)
XCTAssertEqual(todo.title, title)
XCTAssertEqual(todo.accomplished, false)
XCTAssertEqual(todo.order, nil)
})
}Effectively, that is unhealthy, we should not be capable to create a todo merchandise with out a title. We might use the built-in validation API to verify consumer enter, however actually talking that is not the perfect strategy.
My situation with validation is that to start with you possibly can’t return customized error messages and the opposite essential motive is that validation in Vapor is just not async by default. Ultimately you will face a scenario when it’s worthwhile to validate an object primarily based on a db name, then you possibly can’t match that a part of the article validation course of into different non-async discipline validation. IMHO, this ought to be unified. 🥲
Fort the sake of simplicity we’ll begin with a customized validation methodology, this time with none async logic concerned, in a while I am going to present you tips on how to construct a generic validation & error reporting mechanism on your JSON-based RESTful API.
import Vapor
import TodoApi
extension TodoModel {
func create(_ enter: TodoCreateObject) {
title = enter.title
accomplished = enter.accomplished
order = enter.order
}
static func validateCreate(_ enter: TodoCreateObject) throws {
guard !enter.title.isEmpty else {
throw Abort(.badRequest, motive: "Title is required")
}
}
}Within the create controller we will merely name the throwing validateCreate perform, if one thing goes mistaken the Abort error might be returned as a response. It’s also potential to make use of an async methodology (return with an EventLoopFuture) then await (flatMap) the decision and return our newly created todo if all the things was wonderful.
func create(req: Request) throws -> EventLoopFuture<Response> {
let enter = strive req.content material.decode(TodoCreateObject.self)
strive TodoModel.validateCreate(enter)
let todo = TodoModel()
todo.create(enter)
return todo
.create(on: req.db)
.map { todo.mapGet() }
.encodeResponse(standing: .created, for: req)
}The very last thing that now we have to do is to replace our take a look at case and verify for an error response.
struct ErrorResponse: Content material {
let error: Bool
let motive: String
}
func testCreateInvalidTodo() throws {
let app = Software(.testing)
defer { app.shutdown() }
strive configure(app)
strive app.take a look at(.POST, "/todos/", beforeRequest: { req in
let enter = TodoCreateObject(title: "")
strive req.content material.encode(enter)
}, afterResponse: { res in
XCTAssertEqual(res.standing, .badRequest)
let error = strive res.content material.decode(ErrorResponse.self)
XCTAssertEqual(error.motive, "Title is required")
})
}Writing checks is a good way to debug our server facet Swift code and double verify our API endpoints. My solely situation with this strategy is that the code is not an excessive amount of self-explaining.
Declarative unit checks utilizing Spec XCTVapor and the whole take a look at framework works simply nice, however I had a small downside with it. Should you ever labored with JavaScript or TypeScript you might need heard concerning the SuperTest library. This little npm bundle provides us a declarative syntactical sugar for testing HTTP requests, which I favored means an excessive amount of to return to common XCTVapor-based take a look at instances.
That is the explanation why I’ve created the Spec “micro-framework”, which is actually one file with with an additional skinny layer round Vapor’s unit testing framework to supply a declarative API. Let me present you the way this works in observe, utilizing a real-world instance. 🙃
import PackageDescription
let bundle = Package deal(
title: "myProject",
platforms: [
.macOS(.v10_15)
],
merchandise: [
.library(name: "TodoApi", targets: ["TodoApi"]),
],
dependencies: [
.package(url: "https://github.com/vapor/vapor", from: "4.44.0"),
.package(url: "https://github.com/vapor/fluent", from: "4.0.0"),
.package(url: "https://github.com/vapor/fluent-sqlite-driver", from: "4.0.0"),
.package(url: "https://github.com/binarybirds/spec", from: "1.0.0"),
],
targets: [
.target(name: "TodoApi"),
.target(
name: "App",
dependencies: [
.product(name: "Fluent", package: "fluent"),
.product(name: "FluentSQLiteDriver", package: "fluent-sqlite-driver"),
.product(name: "Vapor", package: "vapor"),
.target(name: "TodoApi")
],
swiftSettings: [
.unsafeFlags(["-cross-module-optimization"], .when(configuration: .launch))
]
),
.goal(title: "Run", dependencies: [.target(name: "App")]),
.testTarget(title: "AppTests", dependencies: [
.target(name: "App"),
.product(name: "XCTVapor", package: "vapor"),
.product(name: "Spec", package: "spec"),
])
]
)We had some expectations for the earlier calls, proper? How ought to we take a look at the replace todo endpoint? Effectively, we will create a brand new merchandise, then replace it and verify if the outcomes are legitimate.
import Spec
func testUpdateTodo() throws {
let app = Software(.testing)
defer { app.shutdown() }
strive configure(app)
var existingTodo: TodoGetObject?
strive app
.describe("A legitimate todo object ought to exists after creation")
.put up("/todos/")
.physique(TodoCreateObject(title: "pattern"))
.count on(.created)
.count on(.json)
.count on(TodoGetObject.self) { existingTodo = $0 }
.take a look at()
XCTAssertNotNil(existingTodo)
let updatedTitle = "Merchandise is finished"
strive app
.describe("Todo ought to be up to date")
.put("/todos/" + existingTodo!.id.uuidString)
.physique(TodoUpdateObject(title: updatedTitle, accomplished: true, order: 2))
.count on(.okay)
.count on(.json)
.count on(TodoGetObject.self) { todo in
XCTAssertEqual(todo.title, updatedTitle)
XCTAssertTrue(todo.accomplished)
XCTAssertEqual(todo.order, 2)
}
.take a look at()
}The very first a part of the code expects that we had been capable of create a todo object, it’s the very same create expectation as we used to put in writing with the assistance of the XCTVapor framework.
IMHO the general code high quality is means higher than it was within the earlier instance. We described the take a look at situation then we set our expectations and at last we run our take a look at. With this format it is going to be extra easy to grasp take a look at instances. Should you examine the 2 variations the create case the second is trivial to grasp, however within the first one you really need to take a deeper take a look at every line to grasp what is going on on.
Okay, yet one more take a look at earlier than we cease, let me present you tips on how to describe the delete endpoint. We’ll refactor our code a bit, since there are some duplications already.
@testable import App
import TodoApi
import Fluent
import Spec
ultimate class AppTests: XCTestCase {
personal struct ErrorResponse: Content material {
let error: Bool
let motive: String
}
@discardableResult
personal func createTodo(app: Software, enter: TodoCreateObject) throws -> TodoGetObject {
var existingTodo: TodoGetObject?
strive app
.describe("A legitimate todo object ought to exists after creation")
.put up("/todos/")
.physique(enter)
.count on(.created)
.count on(.json)
.count on(TodoGetObject.self) { existingTodo = $0 }
.take a look at()
XCTAssertNotNil(existingTodo)
return existingTodo!
}
func testTodoList() throws {
let app = Software(.testing)
defer { app.shutdown() }
strive configure(app)
strive app
.describe("A legitimate todo checklist web page ought to be returned.")
.get("/todos/")
.count on(.okay)
.count on(.json)
.count on(Web page<TodoListObject>.self)
.take a look at()
}
func testCreateTodo() throws {
let app = Software(.testing)
defer { app.shutdown() }
strive configure(app)
strive createTodo(app: app, enter: TodoCreateObject(title: "Write a todo tutorial"))
}
func testCreateInvalidTodo() throws {
let app = Software(.testing)
defer { app.shutdown() }
strive configure(app)
strive app
.describe("An invalid title response ought to be returned")
.put up("/todos/")
.physique(TodoCreateObject(title: ""))
.count on(.badRequest)
.count on(.json)
.count on(ErrorResponse.self) { error in
XCTAssertEqual(error.motive, "Title is required")
}
.take a look at()
}
func testUpdateTodo() throws {
let app = Software(.testing)
defer { app.shutdown() }
strive configure(app)
let todo: TodoGetObject? = strive createTodo(app: app, enter: TodoCreateObject(title: "Write a todo tutorial"))
let updatedTitle = "Merchandise is finished"
strive app
.describe("Todo ought to be up to date")
.put("/todos/" + todo!.id.uuidString)
.count on(.okay)
.count on(.json)
.physique(TodoUpdateObject(title: updatedTitle, accomplished: true, order: 2))
.count on(TodoGetObject.self) { todo in
XCTAssertEqual(todo.title, updatedTitle)
XCTAssertTrue(todo.accomplished)
XCTAssertEqual(todo.order, 2)
}
.take a look at()
}
func testDeleteTodo() throws {
let app = Software(.testing)
defer { app.shutdown() }
strive configure(app)
let todo: TodoGetObject? = strive createTodo(app: app, enter: TodoCreateObject(title: "Write a todo tutorial"))
strive app
.describe("Todo ought to be up to date")
.delete("/todos/" + todo!.id.uuidString)
.count on(.okay)
.take a look at()
}
}That is how one can create a whole unit take a look at situation for a REST API endpoint utilizing the Spec library. After all there are a dozen different points that we might repair, reminiscent of higher enter object validation, unit take a look at for the patch endpoint, higher checks for edge instances. Effectively, subsequent time. 😅
Through the use of Spec you possibly can construct your expectations by describing the use case, then you possibly can place your expectations on the described “specification” run the connected validators. The good factor about this declarative strategy is the clear self-explaining format that you could perceive with out taking an excessive amount of time on investigating the underlying Swift / Vapor code.
I consider that Spec is a enjoyable little instrument that lets you write higher checks on your Swift backend apps. It has a really light-weight footprint, and the API is easy and straightforward to make use of. 💪
