Enhanced Bundle Locator (#23)

Author: jagreenwood

Package.resolved

@@ -6,8 +6,8 @@
         "repositoryURL": "https://github.com/apple/swift-argument-parser",
         "state": {
           "branch": null,
-          "revision": "35b76bf577d3cc74820f8991894ce3bcdf024ddc",
-          "version": "0.0.2"
+          "revision": "e394bf350e38cb100b6bc4172834770ede1b7232",
+          "version": "1.0.3"
         }
       }
     ]

Package.swift

@@ -12,7 +12,7 @@ let package = Package(
         .executable(name: "lingo", targets: ["Lingo"])
     ],
     dependencies: [
-        .package(url: "https://github.com/apple/swift-argument-parser", .upToNextMinor(from: "0.0.1")),
+        .package(url: "https://github.com/apple/swift-argument-parser", .upToNextMinor(from: "1.0.0")),
     ],
     targets: [
         .target(

Sources/Core/LingoCore.swift

@@ -28,14 +28,14 @@
 import Foundation
 
 public struct LingoCore {
-    public static func run(input: String, output: String) throws {
+    public static func run(input: String, output: String, packageName: String?) throws {
         guard let fileData = FileHandler.readFiles(inputPath: input, outputPath: output) else {
             throw LingoError.custom("Couldn't read files. Did you type your arguments incorrectly?")
         }
 
         let keyValues = KeyGenerator.generate(localizationFileContents: fileData.input)
         let generatedStructs = StructGenerator.generate(keyValues: keyValues)
-        let swift = SwiftGenerator.generate(structs: generatedStructs, keyValues: keyValues)
+        let swift = SwiftGenerator.generate(structs: generatedStructs, keyValues: keyValues, packageName: packageName)
 
         try FileHandler.writeOutput(swift: swift, to: output)
     }

Sources/Core/SwiftGenerator.swift

@@ -28,16 +28,16 @@
 import Foundation
 
 public struct SwiftGenerator {
-    public static func generate(structs: [Struct], keyValues: [String:String]) -> String {
+    public static func generate(structs: [Struct], keyValues: [String:String], packageName: String?) -> String {
         var swift = "// This file is autogenerated by Lingo from your localized strings file.\n\n"
         swift += "import Foundation\n\n"
         swift += "private class BundleLocator {\n"
         swift += "    static let bundle: Bundle = {\n"
-        swift += "      #if SWIFT_PACKAGE\n"
-        swift += "        return Bundle.module\n"
-        swift += "      #else\n"
-        swift += "        return Bundle(for: BundleLocator.self)\n"
-        swift += "      #endif\n"
+        swift += "        #if SWIFT_PACKAGE\n"
+        swift += "            \(modulde(packageName))\n"
+        swift += "        #else\n"
+        swift += "            return Bundle(for: BundleLocator.self)\n"
+        swift += "        #endif\n"
         swift += "    }()\n"
         swift += "}\n\n"
         swift += "public struct Lingo {\n"
@@ -65,4 +65,35 @@ public struct SwiftGenerator {
         swift += "\n    }"
         return swift
     }
+
+    private static func modulde(_ packageName: String?) -> String {
+        if let packageName = packageName {
+            return """
+            let bundleName = "\(packageName)_\(packageName)"
+                        let candidates = [
+                            /* Bundle should be present here when the package is linked into an App. */
+                            Bundle.main.resourceURL,
+                            /* Bundle should be present here when the package is linked into a framework. */
+                            Bundle(for: BundleLocator.self).resourceURL,
+                            /* For command-line tools. */
+                            Bundle.main.bundleURL,
+                            /* Bundle should be present here when the package is used in UI Tests. */
+                            Bundle(for: BundleLocator.self).resourceURL?.deletingLastPathComponent(),
+                            /* Bundle should be present here when running previews from a different package (this is the path to "…/Debug-iphonesimulator/"). */
+                            Bundle(for: BundleLocator.self).resourceURL?.deletingLastPathComponent().deletingLastPathComponent()
+                        ]
+
+                        for candidate in candidates {
+                            let bundlePath = candidate?.appendingPathComponent(bundleName + ".bundle")
+                            if let bundle = bundlePath.flatMap(Bundle.init(url:)) {
+                                return bundle
+                            }
+                        }
+
+                        fatalError("unable to find bundle named \\(bundleName)")
+            """
+        } else {
+            return "return Bundle.module"
+        }
+    }
 }

Sources/Lingo/main.swift

@@ -35,8 +35,16 @@ struct Lingo: ParsableCommand {
     @Option(help: "path including file name to write Swift to")
     var output: String
 
+    @Option(
+        help: ArgumentHelp(
+            "The name of the SPM package which `Lingo.swift` will belong to.",
+            discussion: "If you are using SwiftUI and your strings file (and Lingo.swift) belong to a Swift package, specify that Swift package's name with this option. Without it SwiftUI previews will fatal error.",
+            valueName: "package-name")
+    )
+    var packageName: String?
+
     func run() throws {
-        try LingoCore.run(input: input, output: output)
+        try LingoCore.run(input: input, output: output, packageName: packageName)
     }
 }
 

Tests/LingoTests/LingoTests.swift

@@ -77,7 +77,7 @@ class LingoTests: XCTestCase {
         let keyValues = ["Lingo.Title": "\"Lingo\"", "Lingo.WasHisName": "\"Oh\"", "Flair.Description": "\"As in pieces of flair from Office Space the movie\"", "MONK.Title": "\"A networking lib\""]
 
         let structs = StructGenerator.generate(keyValues: keyValues)
-        let swift = SwiftGenerator.generate(structs: structs, keyValues: keyValues)
+        let swift = SwiftGenerator.generate(structs: structs, keyValues: keyValues, packageName: nil)
 
         XCTAssert(swift == LingoTests.expectedText, "Generated Swift doesn't match expected")
     }
@@ -110,7 +110,7 @@ class LingoTests: XCTestCase {
         let url = try! LingoTests.write(LingoTests.localizableStrings, toTemp: "input")
         measure {
             do {
-                try LingoCore.run(input: url.path, output: outputURL.path)
+                try LingoCore.run(input: url.path, output: outputURL.path, packageName: nil)
 
                 let expectedSwift = LingoTests.expectedText
                 let generatedSwift = try? String(contentsOf: self.outputURL)
@@ -135,7 +135,7 @@ private extension LingoTests {
 
     static var expectedText: String {
         return """
-        // This file is autogenerated by Lingo from your localized strings file.\n\nimport Foundation\n\nprivate class BundleLocator {\n    static let bundle: Bundle = {\n      #if SWIFT_PACKAGE\n        return Bundle.module\n      #else\n        return Bundle(for: BundleLocator.self)\n      #endif\n    }()\n}\n\npublic struct Lingo {\n    public struct Flair {\n        /// \"As in pieces of flair from Office Space the movie\"\n        public static let description = NSLocalizedString(\"Flair.Description\", bundle: BundleLocator.bundle, comment: \"\")\n    }\n\n    public struct Lingo {\n        /// \"Lingo\"\n        public static let title = NSLocalizedString(\"Lingo.Title\", bundle: BundleLocator.bundle, comment: \"\")\n        /// \"Oh\"\n        public static let wasHisName = NSLocalizedString(\"Lingo.WasHisName\", bundle: BundleLocator.bundle, comment: \"\")\n    }\n\n    public struct MONK {\n        /// \"A networking lib\"\n        public static let title = NSLocalizedString(\"MONK.Title\", bundle: BundleLocator.bundle, comment: \"\")\n    }\n}\n
+        // This file is autogenerated by Lingo from your localized strings file.\n\nimport Foundation\n\nprivate class BundleLocator {\n    static let bundle: Bundle = {\n        #if SWIFT_PACKAGE\n            return Bundle.module\n        #else\n            return Bundle(for: BundleLocator.self)\n        #endif\n    }()\n}\n\npublic struct Lingo {\n    public struct Flair {\n        /// \"As in pieces of flair from Office Space the movie\"\n        public static let description = NSLocalizedString(\"Flair.Description\", bundle: BundleLocator.bundle, comment: \"\")\n    }\n\n    public struct Lingo {\n        /// \"Lingo\"\n        public static let title = NSLocalizedString(\"Lingo.Title\", bundle: BundleLocator.bundle, comment: \"\")\n        /// \"Oh\"\n        public static let wasHisName = NSLocalizedString(\"Lingo.WasHisName\", bundle: BundleLocator.bundle, comment: \"\")\n    }\n\n    public struct MONK {\n        /// \"A networking lib\"\n        public static let title = NSLocalizedString(\"MONK.Title\", bundle: BundleLocator.bundle, comment: \"\")\n    }\n}\n
         """
     }