[Routing][Tooling] Utilize Swift Package Manager tooling

Makefile

@@ -5,7 +5,7 @@ INSTALL_DIR=$(HOME)/.$(shell echo '$(APP_NAME)' | tr '[:upper:]' '[:lower:]')
 BUILD_NUMBER_FILE=./Sources/$(APP_NAME)/App/BuildNumber.swift
 VERSION_FILE=./Sources/$(APP_NAME)/App/Version.swift
 
-SWIFT_BUILD_FLAGS=--configuration release -Xswiftc -static-stdlib
+SWIFT_BUILD_FLAGS=--configuration release
 APP_EXECUTABLE=$(shell swift build $(SWIFT_BUILD_FLAGS) --show-bin-path)/$(APP_NAME)
 
 # ZSH_COMMAND · run single command in `zsh` shell, ignoring most `zsh` startup files.
@@ -79,7 +79,7 @@ ifdef NEW_VERSION
 	$(eval MAJOR:=$(word 1,$(VERSION_COMPONENTS)))
 	$(eval MINOR:=$(word 2,$(VERSION_COMPONENTS)))
 	$(eval PATCH:=$(word 3,$(VERSION_COMPONENTS)))
-	@echo "import $(APP_NAME)Core\n\nlet appVersion: Version = .init(major: $(MAJOR), minor: $(MINOR), patch: $(PATCH))" > $(VERSION_FILE)
+	@echo "import struct Utility.Version\n\nlet appVersion: Version = .init($(MAJOR), $(MINOR), $(PATCH))" > $(VERSION_FILE)
 endif
 
 %:

Package.resolved

@@ -1,6 +1,15 @@
 {
   "object": {
     "pins": [
+      {
+        "package": "SwiftPM",
+        "repositoryURL": "git@github.com:apple/swift-package-manager.git",
+        "state": {
+          "branch": null,
+          "revision": "235aacc514cb81a6881364b0fedcb3dd083228f3",
+          "version": "0.3.0"
+        }
+      },
       {
         "package": "SnapshotTesting",
         "repositoryURL": "https://github.com/pointfreeco/swift-snapshot-testing",

Package.swift

@@ -9,24 +9,19 @@ let package = Package(
         .library(name: "DiffFormatterApp", targets: ["DiffFormatterApp"])
     ],
     dependencies: [
-        .package(url: "https://github.com/pointfreeco/swift-snapshot-testing", from: "1.1.0")
+        .package(url: "git@github.com:pointfreeco/swift-snapshot-testing", from: "1.1.0"),
+        .package(url: "git@github.com:apple/swift-package-manager.git", from: "0.3.0")
     ],
     targets: [
         .target(
             name: "DiffFormatter",
             dependencies: ["DiffFormatterApp"]),
         .target(
             name: "DiffFormatterApp",
-            dependencies: ["DiffFormatterCore", "DiffFormatterRouting", "DiffFormatterTelemetry", "DiffFormatterUtilities"]),
+            dependencies: ["DiffFormatterCore", "Utility"]),
         .target(
             name: "DiffFormatterCore",
             dependencies: ["DiffFormatterUtilities"]),
-        .target(
-            name: "DiffFormatterRouting",
-            dependencies: ["DiffFormatterCore", "DiffFormatterUtilities"]),
-        .target(
-            name: "DiffFormatterTelemetry",
-            dependencies: []),
         .target(
             name: "DiffFormatterUtilities",
             dependencies: []),

Sources/DiffFormatter/App/Version.swift

@@ -1,3 +1,3 @@
-import DiffFormatterCore
+import struct Utility.Version
 
-let appVersion: Version = .init(major: 0, minor: 0, patch: 17)
+let appVersion: Version = .init(0, 0, 17)

Sources/DiffFormatter/main.swift

@@ -7,11 +7,24 @@
 //
 
 import DiffFormatterApp
-import DiffFormatterCore
+import DiffFormatterUtilities
 import Foundation
 
-App(
+let processInfo: ProcessInfo = .processInfo
+
+let meta: App.Meta = .init(
     buildNumber: appBuildNumber,
     name: appName,
     version: appVersion
-).run(processInfo: ProcessInfo.processInfo)
+)
+
+let runner = AppRunner(
+    environment: processInfo.environment,
+    meta: meta
+)
+
+do {
+    try runner.run(arguments: processInfo.arguments)
+} catch {
+    Output.instance.print("\(error)", kind: .error)
+}

Sources/DiffFormatterApp/App.swift

@@ -6,34 +6,53 @@
 //  Copyright © 2019 DHL. All rights reserved.
 //
 
-import DiffFormatterCore
-import DiffFormatterRouting
-import DiffFormatterTelemetry
-import Foundation
-
-extension App {
-    public func run(processInfo: ProcessInfo) {
-        let args: [String] = Array(processInfo
-            .arguments
-            .dropFirst() // Remove app name/command
-        )
-
-        let scheme = ArgumentScheme(arguments: args)
-
-        let configurator = Configurator(processInfo: processInfo, argScheme: scheme)
-
-        let router = ArgumentRouter(
-            app: self,
-            configuration: configurator.configuration,
-            handlers: [
-                ArgumentRouter.usageHandler,
-                ArgumentRouter.versionHandler,
-                ArgumentRouter.diffHandler
-            ]
-        )
-
-        if case .notHandled = router.route(argScheme: scheme) {
-            log.error("Unable to handle included arguments")
+import struct Utility.Version
+import struct DiffFormatterCore.Configuration
+import DiffFormatterUtilities
+
+typealias Version = Utility.Version
+
+public struct App {
+    public struct Meta {
+        public typealias Version = Utility.Version
+
+        let buildNumber: Int
+        let name: String
+        let version: Version
+
+        public init(buildNumber: Int, name: String, version: Version) {
+            self.buildNumber = buildNumber
+            self.name = name
+            self.version = version
         }
     }
+    public struct Options {
+        var projectDir: String?
+        var shouldPrintVersion: Bool
+        var verbose: Bool
+    }
+
+    public let configuration: Configuration
+    public let meta: Meta
+    public let options: Options
+    private let output: OutputType
+
+    init(configuration: Configuration, meta: Meta, options: Options, output: OutputType = Output.instance) {
+        self.configuration = configuration
+        self.meta = meta
+        self.options = options
+        self.output = output
+    }
+
+    func print(_ value: String, kind: Output.Kind = .default) {
+        output.print(value, kind: kind, verbose: options.verbose)
+    }
+}
+
+extension App.Options {
+    static let blank: App.Options = .init(
+        projectDir: nil,
+        shouldPrintVersion: false,
+        verbose: false
+    )
 }

Sources/DiffFormatterApp/AppRunner.swift

@@ -0,0 +1,51 @@
+//
+//  AppRunner.swift
+//  DiffFormatterApp
+//
+//  Created by Dan Loman on 1/29/19.
+//
+
+public class AppRunner {
+    private let environment: Environment
+
+    private let meta: App.Meta
+
+    private let registry: CommandRegistry
+
+    public init(environment: Environment, meta: App.Meta) {
+        self.environment = environment
+        self.meta = meta
+        self.registry = .init(meta: meta)
+
+        registry.register {
+            GenerateCommand(meta: meta, parser: $0).bindingGlobalOptions(to: $1)
+        }
+    }
+
+    public func run(arguments: [String]) throws {
+        let args = Array(arguments.dropFirst())
+
+        let (command, options, result) = try registry.parse(arguments: args)
+
+        let config = Configurator(
+            options: options,
+            meta: meta,
+            environment: environment
+        ).configuration
+
+        let app: App = .init(configuration: config, meta: meta, options: options)
+
+        if let command = command {
+            try registry.runCommand(
+                named: command,
+                with: result,
+                app: app,
+                env: environment
+            )
+        } else if options.shouldPrintVersion {
+            app.print("\(app.meta.name) \(app.meta.version) (\(app.meta.buildNumber))")
+        } else {
+            registry.printUsage()
+        }
+    }
+}

Sources/DiffFormatterApp/Command-Routing/Command.swift

@@ -0,0 +1,18 @@
+//
+//  Command.swift
+//  DiffFormatterApp
+//
+//  Created by Dan Loman on 1/29/19.
+//
+
+import Utility
+
+public typealias ParsingResult = ArgumentParser.Result
+public typealias Environment = [String: String]
+
+protocol Command {
+    var name: String { get }
+
+    func run(with result: ParsingResult, app: App, env: Environment) throws
+    func bindingGlobalOptions(to binder: ArgumentBinder<App.Options>) -> Self
+}

Sources/DiffFormatterApp/Command-Routing/CommandRegistry.swift

@@ -0,0 +1,69 @@
+//
+//  CommandRegistry.swift
+//  DiffFormatterApp
+//
+//  Created by Dan Loman on 1/29/19.
+//
+
+import Foundation
+import Utility
+import var Basic.stdoutStream
+
+final class CommandRegistry {
+    typealias Binder = ArgumentBinder<App.Options>
+
+    private let binder: Binder = .init()
+
+    private var commands: [Command] = []
+
+    private let parser: ArgumentParser
+
+    init(meta: App.Meta) {
+        // swiftlint:disable line_length
+        self.parser = .init(
+            usage: "generate <version1> <version2> [--option]...",
+            overview: "\(meta.name) is a flexible tool for generating well-formatted changelogs between application versions",
+            seeAlso: "Visit https://github.com/namolnad/\(meta.name) for more information"
+        )
+        // swiftlint:enable line_length
+
+        bindOptions(to: binder, using: parser, meta: meta)
+    }
+
+    // swiftlint:disable large_tuple
+    func parse(arguments: [String]) throws -> (String?, App.Options, ParsingResult) {
+        let result = try parser.parse(arguments)
+
+        var options: App.Options = .blank
+
+        try binder.fill(parseResult: result, into: &options)
+
+        return (result.subparser(parser), options, result)
+    }
+    // swiftlint:enable large_tuple
+
+    func printUsage() {
+        parser.printUsage(on: stdoutStream)
+    }
+
+    func register(command: (ArgumentParser, Binder) -> Command) {
+        self.commands.append(command(parser, binder))
+    }
+
+    func runCommand(named name: String, with result: ParsingResult, app: App, env: Environment) throws {
+        guard let command = commands.first(where: { $0.name == name }) else {
+            return
+        }
+
+        return try command.run(with: result, app: app, env: env)
+    }
+
+    private func bindOptions(to binder: Binder, using parser: ArgumentParser, meta: App.Meta) {
+        binder.bind(option: parser.add(
+            option: "--version",
+            shortName: "-V",
+            kind: Bool.self,
+            usage: "Displays current \(meta.name) version and build number"
+        )) { $0.shouldPrintVersion = $1 }
+    }
+}