✨ Add embeddable ACKLocalizationCommand

.claude/CLAUDE.md

@@ -17,10 +17,11 @@ Tests use **Swift Testing** (`@Test`/`#expect`), not XCTest.
 
 ## Architecture
 
-Two targets with a thin executable wrapper:
+Two library targets with a thin executable wrapper:
 
-- `Sources/ACKLocalization/main.swift` — executable; just instantiates `ACKLocalization` and calls `run()`.
-- `Sources/ACKLocalizationCore` — all logic, exposed as a library so it is testable.
+- `Sources/ACKLocalization` — executable; only marks `ACKLocalizationCommand` as `@main`.
+- `Sources/ACKLocalizationCommands` — library with the public `ACKLocalizationCommand` (swift-argument-parser `AsyncParsableCommand`, command name `localization`) that instantiates `ACKLocalization` and runs it; exposed so other tools can embed it (e.g. as a subcommand).
+- `Sources/ACKLocalizationCore` — all logic, exposed as a library so it is testable; does not depend on ArgumentParser.
 
 The pipeline lives in `ACKLocalizationCore/ACKLocalization.swift` and runs: load `localization.json` (`Model/Configuration.swift`, with fallback decoding of the legacy `ConfigurationV1` format) → resolve credentials (config values take priority over the `ACKLOCALIZATION_SERVICE_ACCOUNT_PATH` / `ACKLOCALIZATION_API_KEY` env vars, service account over API key, ADC as last resort) → fetch spreadsheet via `SheetsAPIService` → `transformValues` maps sheet columns to languages via `languageMapping` → `saveMappedValues` groups rows per output file (keys prefixed `plist.<FileName>.` go to `<FileName>.strings`, plural keys `key##{rule}` go to `.stringsdict`) and writes via `FileSystem`.
 

CHANGELOG.md

@@ -9,6 +9,8 @@
 ## main
 
 ### Changed
+- Use [Swift Argument Parser](https://github.com/apple/swift-argument-parser) for command-line handling, the command is available as `ACKLocalizationCommand` in the new `ACKLocalizationCommands` library so it can be embedded in other tools ([#48](https://github.com/AckeeCZ/ACKLocalization/pull/48), kudos to @olejnjak)
+- `ACKLocalization.run()` no longer calls `exit(1)` on failure, it displays the error and rethrows it instead ([#48](https://github.com/AckeeCZ/ACKLocalization/pull/48), kudos to @olejnjak)
 - Replace internal Combine usage with async/await ([#47](https://github.com/AckeeCZ/ACKLocalization/pull/47), kudos to @olejnjak)
 - Migrate tests to Swift Testing and extend test coverage ([#47](https://github.com/AckeeCZ/ACKLocalization/pull/47), kudos to @olejnjak)
 

Package.swift

@@ -11,6 +11,9 @@ let package = Package(
         .library(
             name: "ACKLocalizationCore",
             targets: ["ACKLocalizationCore"]),
+        .library(
+            name: "ACKLocalizationCommands",
+            targets: ["ACKLocalizationCommands"]),
         .executable(
             name: "ACKLocalization",
             targets: ["ACKLocalization"]),
@@ -20,6 +23,10 @@ let package = Package(
             url: "https://github.com/olejnjak/google-auth-swift",
             from: "0.1.1"
         ),
+        .package(
+            url: "https://github.com/apple/swift-argument-parser",
+            from: "1.8.2"
+        ),
     ],
     targets: [
         .target(
@@ -31,9 +38,19 @@ let package = Package(
                 ),
             ]
         ),
+        .target(
+            name: "ACKLocalizationCommands",
+            dependencies: [
+                "ACKLocalizationCore",
+                .product(
+                    name: "ArgumentParser",
+                    package: "swift-argument-parser"
+                ),
+            ]
+        ),
         .executableTarget(
             name: "ACKLocalization",
-            dependencies: ["ACKLocalizationCore"]),
+            dependencies: ["ACKLocalizationCommands"]),
         .testTarget(
             name: "ACKLocalizationCoreTests",
             dependencies: ["ACKLocalizationCore"]),

Sources/ACKLocalization/ACKLocalizationCommand+Main.swift

@@ -0,0 +1,4 @@
+import ACKLocalizationCommands
+
+@main
+extension ACKLocalizationCommand { }

Sources/ACKLocalizationCommands/ACKLocalizationCommand.swift

@@ -0,0 +1,22 @@
+import ACKLocalizationCore
+import ArgumentParser
+
+public struct ACKLocalizationCommand: AsyncParsableCommand {
+    public static let configuration = CommandConfiguration(
+        commandName: "localization",
+        abstract: "Generates localization files from a Google Spreadsheet using `localization.json` in the current directory."
+    )
+
+    public init() { }
+
+    public func run() async throws {
+        let localization = ACKLocalization()
+
+        do {
+            try await localization.run()
+        } catch {
+            // error has already been displayed by `ACKLocalization`
+            throw ExitCode.failure
+        }
+    }
+}

Sources/ACKLocalizationCore/ACKLocalization.swift

@@ -27,16 +27,18 @@ public final class ACKLocalization {
     // MARK: - Public interface
 
     /// Main that loads configuration from _localization.json_, fetches access token and loads content of spreadsheet
-    public func run() async {
+    ///
+    /// Errors are displayed before being rethrown
+    public func run() async throws {
         do {
             let config = try loadConfiguration()
             try await run(configuration: config)
         } catch let error as LocalizationError {
             displayError(error)
-            exit(1)
+            throw error
         } catch {
             print(error)
-            exit(1)
+            throw error
         }
     }