Output / error overhaul

.swiftlint.yml

@@ -24,11 +24,15 @@ disabled_rules:
 - no_magic_numbers
 - prefixed_toplevel_constant
 - sorted_enum_cases
+- strict_fileprivate
 - vertical_whitespace_between_cases
+- void_function_in_ternary
 attributes:
   always_on_line_above: ['@MainActor', '@OptionGroup']
 closure_body_length:
   warning: 40
+cyclomatic_complexity:
+  warning: 11
 file_types_order:
   order:
   - main_type
@@ -37,7 +41,7 @@ file_types_order:
   - preview_provider
   - library_content_provider
 function_body_length:
-  warning: 55
+  warning: 70
 indentation_width:
   include_multiline_strings: false
 number_separator:

Package.swift

@@ -17,6 +17,7 @@ let package = Package(
 		.package(url: "https://github.com/Quick/Nimble.git", from: "13.7.1"),
 		.package(url: "https://github.com/Quick/Quick.git", exact: "7.5.0"),
 		.package(url: "https://github.com/apple/swift-argument-parser.git", from: "1.5.0"),
+		.package(url: "https://github.com/apple/swift-atomics.git", branch: "main"),
 		.package(url: "https://github.com/funky-monkey/IsoCountryCodes.git", from: "1.0.2"),
 		.package(url: "https://github.com/mxcl/Version.git", from: "2.1.0"),
 	],
@@ -25,6 +26,7 @@ let package = Package(
 			name: "mas",
 			dependencies: [
 				.product(name: "ArgumentParser", package: "swift-argument-parser"),
+				.product(name: "Atomics", package: "swift-atomics"),
 				"IsoCountryCodes",
 				"Version",
 			],

README.md

@@ -100,7 +100,7 @@ $ mas search Xcode
 
 #### `mas info`
 
-`mas info <app-id>` displays more detailed information about an application available from the Mac App Store.
+`mas info <app-id>` outputs more detailed information about an application available from the Mac App Store.
 
 ```console
 $ mas info 497799835
@@ -118,7 +118,7 @@ All the commands in this section require you to be logged into an Apple Account
 
 #### `mas list`
 
-`mas list` displays all the applications on your Mac that were installed from the Mac App Store.
+`mas list` outputs all the applications on your Mac that were installed from the Mac App Store.
 
 ```console
 $ mas list
@@ -129,7 +129,7 @@ $ mas list
 
 #### `mas outdated`
 
-`mas outdated` displays all applications installed from the Mac App Store on your Mac that have pending upgrades.
+`mas outdated` outputs all applications installed from the Mac App Store on your Mac that have pending upgrades.
 
 ```console
 $ mas outdated

Sources/mas/AppStore/Downloader.swift

@@ -8,86 +8,52 @@
 
 private import CommerceKit
 
-/// Sequentially downloads apps, printing progress to the console.
-///
-/// Verifies that each supplied app ID is valid before attempting to download.
-///
-/// - Parameters:
-///   - appIDs: The app IDs of the apps to be verified & downloaded.
-///   - searcher: The `AppStoreSearcher` used to verify app IDs.
-///   - purchasing: Flag indicating if the apps will be purchased. Only works for free apps. Defaults to false.
-/// - Throws: If any download fails, immediately throws an error.
-func downloadApps(
-	withAppIDs appIDs: [AppID],
-	verifiedBy searcher: AppStoreSearcher,
-	purchasing: Bool = false
-) async throws {
-	for appID in appIDs {
+struct Downloader {
+	let printer: Printer
+
+	func downloadApp(
+		withAppID appID: AppID,
+		purchasing: Bool = false,
+		withAttemptCount attemptCount: UInt32 = 3
+	) async throws {
 		do {
-			_ = try await searcher.lookup(appID: appID)
-			try await downloadApp(withAppID: appID, purchasing: purchasing, withAttemptCount: 3)
+			let purchase = await SSPurchase(appID: appID, purchasing: purchasing)
+			_ = try await withCheckedThrowingContinuation { (continuation: CheckedContinuation<Void, Error>) in
+				CKPurchaseController.shared().perform(purchase, withOptions: 0) { _, _, error, response in
+					if let error {
+						continuation.resume(throwing: error)
+					} else if response?.downloads.isEmpty == false {
+						Task {
+							do {
+								try await PurchaseDownloadObserver(appID: appID, printer: printer).observeDownloadQueue()
+								continuation.resume()
+							} catch {
+								continuation.resume(throwing: error)
+							}
+						}
+					} else {
+						continuation.resume(throwing: MASError.noDownloads)
+					}
+				}
+			}
 		} catch {
-			guard case MASError.unknownAppID = error else {
+			guard attemptCount > 1 else {
 				throw error
 			}
-			printWarning(error)
-		}
-	}
-}
 
-/// Sequentially downloads apps, printing progress to the console.
-///
-/// - Parameters:
-///   - appIDs: The app IDs of the apps to be downloaded.
-///   - purchasing: Flag indicating if the apps will be purchased. Only works for free apps. Defaults to false.
-/// - Throws: If a download fails, immediately throws an error.
-func downloadApps(withAppIDs appIDs: [AppID], purchasing: Bool = false) async throws {
-	for appID in appIDs {
-		try await downloadApp(withAppID: appID, purchasing: purchasing, withAttemptCount: 3)
-	}
-}
-
-private func downloadApp(withAppID appID: AppID, purchasing: Bool, withAttemptCount attemptCount: UInt32) async throws {
-	do {
-		try await downloadApp(withAppID: appID, purchasing: purchasing)
-	} catch {
-		guard attemptCount > 1 else {
-			throw error
-		}
-
-		// If the download failed due to network issues, try again. Otherwise, fail immediately.
-		guard
-			case let MASError.downloadFailed(downloadError) = error,
-			downloadError.domain == NSURLErrorDomain
-		else {
-			throw error
-		}
-
-		let attemptCount = attemptCount - 1
-		printWarning(downloadError.localizedDescription)
-		printWarning("Retrying…", attemptCount, attemptCount == 1 ? "attempt remaining" : "attempts remaining")
-		try await downloadApp(withAppID: appID, purchasing: purchasing, withAttemptCount: attemptCount)
-	}
-}
-
-private func downloadApp(withAppID appID: AppID, purchasing: Bool = false) async throws {
-	let purchase = await SSPurchase(appID: appID, purchasing: purchasing)
-	_ = try await withCheckedThrowingContinuation { (continuation: CheckedContinuation<Void, Error>) in
-		CKPurchaseController.shared().perform(purchase, withOptions: 0) { _, _, error, response in
-			if let error {
-				continuation.resume(throwing: MASError(purchaseFailedError: error))
-			} else if response?.downloads.isEmpty == false {
-				Task {
-					do {
-						try await PurchaseDownloadObserver(appID: appID).observeDownloadQueue()
-						continuation.resume()
-					} catch {
-						continuation.resume(throwing: MASError(purchaseFailedError: error))
-					}
-				}
-			} else {
-				continuation.resume(throwing: MASError.noDownloads)
+			// If the download failed due to network issues, try again. Otherwise, fail immediately.
+			guard (error as NSError).domain == NSURLErrorDomain else {
+				throw error
 			}
+
+			let attemptCount = attemptCount - 1
+			printer.warning(
+				"Network error (",
+				attemptCount,
+				attemptCount == 1 ? " attempt remaining):\n" : " attempts remaining):\n",
+				error
+			)
+			try await downloadApp(withAppID: appID, purchasing: purchasing, withAttemptCount: attemptCount)
 		}
 	}
 }

Sources/mas/AppStore/PurchaseDownloadObserver.swift

@@ -15,12 +15,15 @@ private var downloadedPhaseType: Int64 { 5 }
 
 class PurchaseDownloadObserver: CKDownloadQueueObserver {
 	private let appID: AppID
+	private let printer: Printer
+
 	private var completionHandler: (() -> Void)?
-	private var errorHandler: ((MASError) -> Void)?
+	private var errorHandler: ((Error) -> Void)?
 	private var prevPhaseType: Int64?
 
-	init(appID: AppID) {
+	init(appID: AppID, printer: Printer) {
 		self.appID = appID
+		self.printer = printer
 	}
 
 	deinit {
@@ -38,29 +41,7 @@ class PurchaseDownloadObserver: CKDownloadQueueObserver {
 		if status.isFailed || status.isCancelled {
 			queue.removeDownload(withItemIdentifier: download.metadata.itemIdentifier)
 		} else {
-			let currPhaseType = status.activePhase.phaseType
-			let prevPhaseType = prevPhaseType
-			if prevPhaseType != currPhaseType {
-				switch currPhaseType {
-				case downloadingPhaseType:
-					if prevPhaseType == initialPhaseType {
-						terminateEphemeralPrinting()
-						printNotice("Downloading", download.progressDescription)
-					}
-				case downloadedPhaseType:
-					if prevPhaseType == downloadingPhaseType {
-						terminateEphemeralPrinting()
-						printNotice("Downloaded", download.progressDescription)
-					}
-				case installingPhaseType:
-					terminateEphemeralPrinting()
-					printNotice("Installing", download.progressDescription)
-				default:
-					break
-				}
-				self.prevPhaseType = currPhaseType
-			}
-			progress(status.progressState)
+			prevPhaseType = printer.progress(of: download, prevPhaseType: prevPhaseType)
 		}
 	}
 
@@ -76,13 +57,13 @@ class PurchaseDownloadObserver: CKDownloadQueueObserver {
 			return
 		}
 
-		terminateEphemeralPrinting()
+		printer.terminateEphemeral()
 		if status.isFailed {
-			errorHandler?(MASError(downloadFailedError: status.error))
+			errorHandler?(status.error)
 		} else if status.isCancelled {
-			errorHandler?(.cancelled)
+			errorHandler?(MASError.cancelled)
 		} else {
-			printNotice("Installed", download.progressDescription)
+			printer.notice("Installed", download.progressDescription)
 			completionHandler?()
 		}
 	}
@@ -98,24 +79,58 @@ private struct ProgressState {
 	}
 }
 
-private func progress(_ state: ProgressState) {
-	// Don't display the progress bar if we're not on a terminal
-	guard isatty(fileno(stdout)) != 0 else {
-		return
-	}
-
-	let barLength = 60
-	let completeLength = Int(state.percentComplete * Float(barLength))
-	let bar = (0..<barLength).map { $0 < completeLength ? "#" : "-" }.joined()
-	printEphemeral(bar, state.percentage, state.phase, terminator: "")
-}
-
 private extension SSDownload {
 	var progressDescription: String {
 		"\(metadata.title) (\(metadata.bundleVersion ?? "unknown version"))"
 	}
 }
 
+private extension Printer {
+	func progress(of download: SSDownload, prevPhaseType: Int64?) -> Int64 {
+		let currPhaseType = download.status.activePhase.phaseType
+		if prevPhaseType != currPhaseType {
+			switch currPhaseType {
+			case downloadingPhaseType:
+				if prevPhaseType == initialPhaseType {
+					progressHeader(for: download)
+				}
+			case downloadedPhaseType:
+				if prevPhaseType == downloadingPhaseType {
+					progressHeader(for: download)
+				}
+			case installingPhaseType:
+				progressHeader(for: download)
+			default:
+				break
+			}
+		}
+
+		if isatty(fileno(stdout)) != 0 {
+			// Only output the progress bar if connected to a terminal
+			let progressState = download.status.progressState
+			let totalLength = 60
+			let completedLength = Int(progressState.percentComplete * Float(totalLength))
+			ephemeral(
+				String(repeating: "#", count: completedLength),
+				String(repeating: "-", count: totalLength - completedLength),
+				" ",
+				progressState.percentage,
+				" ",
+				progressState.phase,
+				separator: "",
+				terminator: ""
+			)
+		}
+
+		return currPhaseType
+	}
+
+	private func progressHeader(for download: SSDownload) {
+		terminateEphemeral()
+		notice(download.status.activePhase.phaseDescription, download.progressDescription)
+	}
+}
+
 private extension SSDownloadStatus {
 	var progressState: ProgressState {
 		ProgressState(percentComplete: percentComplete, phase: activePhase.phaseDescription)
@@ -125,6 +140,8 @@ private extension SSDownloadStatus {
 private extension SSDownloadPhase {
 	var phaseDescription: String {
 		switch phaseType {
+		case downloadedPhaseType:
+			"Downloaded"
 		case downloadingPhaseType:
 			"Downloading"
 		case installingPhaseType:

Sources/mas/Commands/Account.swift

@@ -9,15 +9,19 @@
 internal import ArgumentParser
 
 extension MAS {
-	/// Displays the Apple Account signed in to the Mac App Store.
+	/// Outputs the Apple Account signed in to the Mac App Store.
 	struct Account: AsyncParsableCommand {
 		static let configuration = CommandConfiguration(
-			abstract: "Display the Apple Account signed in to the Mac App Store"
+			abstract: "Output the Apple Account signed in to the Mac App Store"
 		)
 
 		/// Runs the command.
 		func run() async throws {
-			printInfo(try await appleAccount.emailAddress)
+			try await mas.run { try await run(printer: $0) }
+		}
+
+		func run(printer: Printer) async throws {
+			printer.info(try await appleAccount.emailAddress)
 		}
 	}
 }