[iOS Dev UK 23] Making developer tools with Swift

feature/MYTICKET-123_name-of-your-branch
Author: Pol Piella Abadia

Date: Sun Aug 20 14:03:41 2023 +0100

My awesome feature

TICKET-123
Branch
Commit

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# !
/usr/bin/env swift

import Foundation

let commitMessageFile = CommandLine.arguments[1]

guard let data = FileManager.default.contents(atPath: commitMessageFile),

let commitMessage = String(data: data, encoding: .utf8) else {

exit(1)

}

let gitBranchName = shell("git rev-parse
--
abbrev-ref HEAD")

.trimmingCharacters(in: .newlines)

let regex = try! NSRegularExpression(pattern: #"(\w+-\d+)"#, options: .anchorsMatchLines)

let stringRange = NSRange(location: 0, length: gitBranchName.utf16.count)

guard let match = regex.firstMatch(in: gitBranchName, range: stringRange) else { exit(0) }

let range = match.range(at: 1)

guard !NSEqualRanges(range, NSMakeRange(NSNotFound, 0)) else { exit(1) }

let ticketNumber = (gitBranchName as NSString)

.substring(with: range)


if !commitMessage.contains(ticketNumber) {

do {

try "\(commitMessage.trimmingCharacters(in:.newlines))\n\n\(ticketNumber)"

.write(toFile: commitMessageFile, atomically: true, encoding: .utf8)

} catch {

print("Could not write to file \(commitMessageFile)")

}

}

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# !
/usr/bin/env swift

import Foundation




exit(1)

}

--
abbrev-ref HEAD")











do {



} catch {


}

}

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chmod +x file_where_hook_code_is

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Not so fast…

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Yes and no…
https://github.com/mxcl/swift-sh

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# !
/usr/bin/env swift-sh

import Foundation




exit(1)

}

--
abbrev-ref HEAD")











do {



} catch {


}

}

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# !
/usr/bin/env swift-sh

import Foundation

import SourceKittenFramework
//
@jpsim
~>
0.34.1




exit(1)

}

--
abbrev-ref HEAD")











do {



} catch {


}

}

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Future-
proofing and
scaling

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swift package init
--
type executable

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//
swift-tools-version: 5.9

import PackageDescription

let package = Package(

name: "GitHookExecutable",

dependencies: [

],

targets: [

.executableTarget(


dependencies: [

]

),

]

)

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//




dependencies: [

.package(url: "https:
//
github.com/apple/swift-argument-parser.git", exact: "1.2.3")

],

targets: [

.executableTarget(


dependencies: [

.product(name: "ArgumentParser", package: "swift-argument-parser")

]

),

]

)

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import ArgumentParser

@main

struct GitHookExecutable: ParsableCommand {

@Argument(help: "The path to the commit message file")

var commitMessagePath: String

func run() throws {

let commitMessage = try String(contentsOfFile: commitMessagePath)

// .
..

}

}

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Learn more about it!
https://www.youtube.com/watch?v=yyOXynCoagE&t=611s

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#2 Running a
build script?

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brew install swiftlint
pod install

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What about
Swift
Packages?

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Swift 5.6 to the rescue!
https://github.com/apple/swift-evolution/blob/main/proposals/0303-swiftpm-extensible-build-tools.md

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//
swift-tools-version:5.7



name: "SwiftLint",

platforms: [.macOS(.v12)],

products: [

.plugin(name: "SwiftLintPlugin", targets: ["SwiftLintPlugin"])

],

dependencies: [

/ / .. .

],

targets: [

.plugin(

name: "SwiftLintPlugin",

capability: .buildTool(),

dependencies: [

.target(name: "SwiftLintBinary", condition: .when(platforms: [.macOS])),

.target(name: "swiftlint", condition: .when(platforms: [.linux]))

]

),

.executableTarget(

name: "swiftlint",

dependencies: [

.product(name: "ArgumentParser", package: "swift-argument-parser"),

"CollectionConcurrencyKit",

"SwiftLintFramework",

"SwiftyTextTable",

]

),

.binaryTarget(

name: "SwiftLintBinary",

url: "https:
//
github.com/realm/SwiftLint/releases/download/0.52.4/SwiftLintBinary-macos.artifactbundle.zip",

checksum: "8a8095e6235a07d00f34a9e500e7568b359f6f66a249f36d12cd846017a8c6f5"

)

]

)
https://github.com/realm/SwiftLint/blob/main/Package.swift

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//



name: "SwiftLint",


products: [


],

dependencies: [

/ / .. .

],

targets: [

.plugin(



dependencies: [



]

),

.executableTarget(

name: "swiftlint",

dependencies: [




"SwiftyTextTable",

]

),

.binaryTarget(


url: "https:
//


)

]

)

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//



name: "SwiftLint",


products: [


],

dependencies: [

/ / .. .

],

targets: [

.plugin(



dependencies: [



]

),

.executableTarget(

name: "swiftlint",

dependencies: [




"SwiftyTextTable",

]

),

.binaryTarget(


url: "https:
//


)

]

)

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//



name: "SwiftLint",


products: [


],

dependencies: [

/ / .. .

],

targets: [

.plugin(



dependencies: [



]

),

.executableTarget(

name: "swiftlint",

dependencies: [




"SwiftyTextTable",

]

),

.binaryTarget(


url: "https:
//


)

]

)

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//



name: "SwiftLint",


products: [


],

dependencies: [

/ / .. .

],

targets: [

.plugin(



dependencies: [



]

),

.executableTarget(

name: "swiftlint",

dependencies: [




"SwiftyTextTable",

]

),

.binaryTarget(


url: "https:
//


)

]

)

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import Foundation

import PackagePlugin

@main

struct SwiftLintPlugin: BuildToolPlugin {

func createBuildCommands(context: PluginContext, target: Target) async throws
-
>
[Command] {

guard let sourceTarget = target as? SourceModuleTarget else {

return []

}

return createBuildCommands(

inputFiles: sourceTarget.sourceFiles(withSuffix: "swift").map(\.path),

packageDirectory: context.package.directory,

workingDirectory: context.pluginWorkDirectory,

tool: try context.tool(named: "swiftlint")

)

}

private func createBuildCommands(

inputFiles: [Path],

packageDirectory: Path,

workingDirectory: Path,

tool: PluginContext.Tool

)
->
[Command] {

// . ..

return [

.prebuildCommand(

displayName: "SwiftLint",

executable: tool.path,

arguments: arguments,

outputFilesDirectory: outputFilesDirectory

)

]

}

}

https://github.com/realm/SwiftLint/blob/main/Plugins/SwiftLintPlugin/SwiftLintPlugin.swift

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import Foundation


@main


-
>
[Command] {


return []

}






)

}


inputFiles: [Path],




)
->
[Command] {

// . ..

return [

.prebuildCommand(





)

]

}

}


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import Foundation


@main


-
>
[Command] {


return []

}






)

}


inputFiles: [Path],




)
->
[Command] {

// . ..

return [

.prebuildCommand(





)

]

}

}


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import Foundation


@main


-
>
[Command] {


return []

}






)

}


inputFiles: [Path],




)
->
[Command] {

// . ..

return [

.prebuildCommand(





)

]

}

}


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//



name: "DemoSwiftPackage",

products: [

.library(


targets: ["DemoSwiftPackage"]

),

],

dependencies: [

//
github.com/realm/SwiftLint.git", exact: "0.52.4")

],

targets: [

.target(


plugins: [

.plugin(name: "SwiftLintPlugin", package: "SwiftLint")

]

)

]

)

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//




products: [

.library(


targets: ["DemoSwiftPackage"]

),

],

dependencies: [

//
github.com/realm/SwiftLint.git", exact: "0.52.4")

],

targets: [

.target(


plugins: [

.plugin(name: "SwiftLintPlugin", package: "SwiftLint")

]

)

]

)

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What about
Xcode
projects?

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import Foundation


#if canImport(XcodeProjectPlugin)

import XcodeProjectPlugin

extension SwiftLintPlugin: XcodeBuildToolPlugin {

func createBuildCommands(context: XcodePluginContext, target: XcodeTarget) throws
-
>
[Command] {

let inputFilePaths = target.inputFiles

.filter { $0.type
==
.source
&&
$0.path.extension
==
"swift" }

.map(\.path)


inputFiles: inputFilePaths,

packageDirectory: context.xcodeProject.directory,



)

}

}

#endif


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Manually
running a
build script?

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import UIKit

public protocol Camera {

func start()

func stop()

func capture(_ completion: @escaping (UIImage?)
->
Void)

func rotate()

}

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import UIKit

//
Protocol to be matched

protocol AutoMockable {}

public protocol Camera: AutoMockable {

func start()

func stop()

func capture(_ completion: @escaping (UIImage?)
->
Void)

func rotate()

}

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./sourcery
--
config ".sourcery.yml"

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//
Generated using Sourcery 1.8.2 — https:
//
github.com/krzysztofzablocki/Sourcery

//
DO NOT EDIT

//
swiftlint:disable line_length

//
swiftlint:disable variable_name

import Foundation

#if os(iOS)
||
os(tvOS)
||
os(watchOS)

import UIKit

#elseif os(OSX)

import AppKit

#endif

class CameraMock: Camera {

//
MARK: - start

var startCallsCount = 0

var startCalled: Bool {

return startCallsCount > 0

}

var startClosure: (()
->
Void)?

func start() {

startCallsCount += 1

startClosure?()

}

//

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What if…

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/ /


import Foundation


name: "Sourcery",

platforms: [ .macOS(.v12) ],

products: [

.plugin(name: "SourceryCommandPlugin", targets: ["SourceryCommandPlugin"])

],

dependencies: [],

targets: [

.executableTarget(

name: "SourceryExecutable",

dependencies: ["SourceryLib"],

path: "SourceryExecutable",

exclude: [

"Info.plist"

]

),

.plugin(

name: "SourceryCommandPlugin",

capability: .command(

intent: .custom(

verb: "sourcery-command",

description: "Sourcery command plugin for code generation"

),

permissions: [

.writeToPackageDirectory(reason: "Need permission to write generated files to package directory")

]

),

dependencies: ["SourceryExecutable"]

)

]

) https://github.com/krzysztofzablocki/Sourcery/blob/master/Package.swift

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/ /


import Foundation


name: "Sourcery",


products: [


],

dependencies: [],

targets: [

.executableTarget(




exclude: [

"Info.plist"

]

),

.plugin(



intent: .custom(



),

permissions: [


]

),


)

]


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/ /


import Foundation


name: "Sourcery",


products: [


],

dependencies: [],

targets: [

.executableTarget(




exclude: [

"Info.plist"

]

),

.plugin(



intent: .custom(



),

permissions: [


]

),


)

]


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import Foundation

@main

struct SourceryCommandPlugin: CommandPlugin {

func performCommand(context: PluginContext, arguments: [String]) async throws {

/ /
Run one per target

for target in context.package.targets {

let configFilePath = target.directory.appending(subpath: ".sourcery.yml").string

let sourcery = try context.tool(named: "SourceryExecutable").path.string

guard FileManager.default.fileExists(atPath: configFilePath) else {

Diagnostics.warning("⚠ Could not find `.sourcery.yml` for target \(target.name)")

continue

}

let sourceryURL = URL(fileURLWithPath: sourcery)

let process = Process()

process.executableURL = sourceryURL

process.arguments = [

"
- -
config",

configFilePath,

"
- -
cacheBasePath",

context.pluginWorkDirectory.string

]

try process.run()

process.waitUntilExit()

let gracefulExit = process.terminationReason
=
=
.exit
&&
process.terminationStatus
==
0

if !gracefulExit {

throw "🛑 The plugin execution failed with reason: \(process.terminationReason.rawValue) and status: \(process.terminationStatus) "

}

}

}

}
https://github.com/krzysztofzablocki/Sourcery/blob/master/Plugins/SourceryCommandPlugin/SourceryCommandPlugin.swift

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//




dependencies: [

//
github.com/apple/swift-argument-parser.git", exact: "1.2.3")

],

targets: [

.executableTarget(


dependencies: [


]

),

]

)

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//




dependencies: [

//
github.com/apple/swift-argument-parser.git", exact: "1.2.3"),

//
github.com/krzysztofzablocki/Sourcery.git", exact: "2.0.3")

],

targets: [

.executableTarget(


dependencies: [


]

),

]

)

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swift package sourcery-command

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What about
Xcode
projects?

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#if canImport(XcodeProjectPlugin)

import XcodeProjectPlugin

extension SourceryCommandPlugin: XcodeCommandPlugin {

func performCommand(context: XcodePluginContext, arguments: [String]) throws {

for target in context.xcodeProject.targets {

guard let configFilePath = target

.inputFiles

.filter({ $0.path.lastComponent
==
".sourcery.yml" })

.first?

.path

.string else {

Diagnostics.warning("⚠ Could not find `.sourcery.yml` in Xcode's input file list")

return

}

let sourcery = try context.tool(named: "SourceryExecutable").path.string

try run(sourcery, withConfig: configFilePath, cacheBasePath: context.pluginWorkDirectory.string)

}

}

}

#endif

https://github.com/krzysztofzablocki/Sourcery/blob/master/Plugins/SourceryCommandPlugin/SourceryCommandPlugin.swift

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#3 Back-End
service?

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How does
this work?

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Ok… but
what are web
hooks?

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issue_comment webhook
https://docs.github.com/en/webhooks/webhook-events-and-payloads#issue_comment

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Creating a
service with
Swift!

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https://github.com/swift-server/swift-aws-lambda-runtime

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It’s just an
executable…

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import AWSLambdaRuntime

import AWSLambdaEvents

@main

struct UploadToTestFlightWebhook: SimpleLambdaHandler {

let snakeCaseDecoder: JSONDecoder

init() {

let decoder = JSONDecoder()

decoder.keyDecodingStrategy = .convertFromSnakeCase

snakeCaseDecoder = decoder

}

func handle(_ request: APIGatewayV2Request, context: LambdaContext) async throws
->
APIGatewayV2Response {

guard let body = request.body,

let bodyData = body.data(using: .utf8),

let request = try? snakeCaseDecoder.decode(GithubWebhookData.self, from: bodyData) else {

return .init(statusCode: .badRequest, body: "Could not parse the request content
...
")

}

guard request.action
==
"created",

request.comment.body.lowercased()
==
"upload to testflight" else {

return .init(statusCode: .ok, body: "Not handling the event
...
")

}

// ...

}

}

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… that runs
on a different
platform

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#!
/bin/bash

product=Webhook

docker run \

--
rm \

--
volume "$(pwd)/:/src" \

--
workdir "/src/" \

swift:5.8-amazonlinux2 \

swift build
--
product $product -c release -Xswiftc -static-stdlib

target=.build/lambda/$product

rm -rf "$target"

mkdir -p "$target"

cp ".build/release/$product" "$target/"

cd "$target"

ln -s "$product" "bootstrap"

zip
--
symlinks lambda.zip *
https://fabianfett.dev/getting-started-with-swift-aws-lambda-runtime

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#!
/bin/bash

swift package \

--
disable-sandbox archive \

--
swift-version 5.8 \

--
output-path . \

--
products Webhook

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#!
/bin/bash

swift package \

--
disable-sandbox archive \

--
swift-version 5.8 \

--
output-path . \

--
products Webhook

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It’s getting better…

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You still need
to upload it…

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service: upload-to-testflight-webhook

frameworkVersion: "3"

configValidationMode: warn

package:

artifact: build/Products/Webhook.zip

provider:

name: aws

region: eu-west-1

httpApi:

payload: "2.0"

cors: true

runtime: provided.al2

architecture: arm64

functions:

webhook:

handler: webhook

memorySize: 256

description: "[${sls:stage}] Upload"

events:

- httpApi:

path: /upload

method: post
Serverless
framework
https://www.serverless.com

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name: Deploy the serverless lambda to AWS

on:

push:

branches:

- main

jobs:

deploy:

runs-on: ubuntu-latest

container:

image: swift:5.8-amazonlinux2

steps:

- uses: actions/checkout@v3

- name: Configure AWS Credentials

uses: aws-actions/configure-aws-credentials@v2

with:

aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}

aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}

aws-region: eu-west-2

- name: Install zip

run: |

yum install -y zip

- name: Install awscli

run: |

yum install -y awscli

- name: Archive the lambda

run: |

./package.sh Webhook

- name: Deploy to AWS

run: |

aws lambda update-function-code \

-
-
function-name webhook \

-
-
zip-file fileb:
//
.build/lambda/Webhook/Webhook.zip

CI/CD
workflow
https://www.polpiella.dev/automatic-deployment-of-swift-aws-lambdas-on-ci-cd

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This is jut the
tip of the
iceberg…

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Even slide decks!
https://github.com/joshdholtz/DeckUI

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Any questions?

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Any questions?
I have stickers too…

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Resources - Plugins
https://www.polpiella.dev/code-generation-using-swift-package-plugins
https://www.polpiella.dev/sourcery-swift-package-command-plugin
https://www.polpiella.dev/load-custom-fonts-with-no-code-using-swift-package-plugins
https://www.polpiella.dev/an-early-look-at-swift-extensible-build-tools
https://theswiftdev.com/beginners-guide-to-swift-package-manager-command-plugins/
https://www.polpiella.dev/binary-targets-in-modern-swift-packages
https://www.polpiella.dev/network-requests-in-swift-package-plugins

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https://www.polpiella.dev/automating-swift-package-releases-with-github-actions
https://www.polpiella.dev/collecting-gihub-actions-workflow-metrics-with-swift
https://www.polpiella.dev/scripting-in-swift-git-hooks
https://github.com/artemnovichkov/Swift-For-Scripting
https://blog.eidinger.info/swift-e-runs-code-directly-from-the-command-line
https://nshipster.com/swift-sh/
Resources - CLI + Scripts

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https://www.areweserveryet.org/
https://www.polpiella.dev/github-webhooks-and-xcode-cloud
https://www.polpiella.dev/swift-async-await-in-aws-lambdas
https://www.polpiella.dev/scheduled-swift-aws-lambdas
https://www.polpiella.dev/automatic-deployment-of-swift-aws-lambdas-on-ci-cd
https://opticalaberration.com/2021/12/proxy-server.html
Resources - ServerSide Swift
https://www.serversideswift.info
https://theswiftdev.com

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[iOS Dev UK 23] Making developer tools with Swift

[iOS Dev UK 23] Making developer tools with Swift

Pol Piella Abadia

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