Polish bundleConfig with strong type checking

Passepartout/App/Constants/Constants+App.swift

@@ -27,10 +27,6 @@ import Foundation
 import UniformTypeIdentifiers
 import SwiftyBeaver
 
-extension Constants {
-    private static let bundleConfig = Bundle.main.infoDictionary?["com.algoritmico.Passepartout.config"] as? [String: Any]
-}
-
 extension Constants {
     enum App {
         static var appId: String {
@@ -40,9 +36,9 @@ extension Constants {
             return identifier
         }
 
-        static let appStoreId = bundleConfig?["appstore_id"] as? String ?? "DUMMY_appstore_id"
+        static let appStoreId: String = bundleConfig("appstore_id")
 
-        static let appGroupId = bundleConfig?["group_id"] as? String ?? "DUMMY_group_id"
+        static let appGroupId: String = bundleConfig("group_id")
 
         static let isBeta: Bool = {
             Bundle.main.isTestFlight
@@ -57,7 +53,7 @@ extension Constants {
 
                 return testAppType
             }
-            if let infoValue = bundleConfig?["app_type"] as? Int,
+            if let infoValue: Int = bundleConfig("app_type"),
                let testAppType = ProductManager.AppType(rawValue: infoValue) {
 
                 return testAppType

Passepartout/Constants.swift

@@ -26,6 +26,16 @@
 import Foundation
 
 enum Constants {
+    static func bundleConfig<T>(_ key: String, in bundle: Bundle? = nil) -> T {
+        guard let config = (bundle ?? .main).infoDictionary?["com.algoritmico.Passepartout.config"] as? [String: Any] else {
+            fatalError("Unable to find config bundle")
+        }
+        guard let value = config[key] as? T else {
+            fatalError("Missing \(key) from config bundle")
+        }
+        return value
+    }
+
     enum Global {
         static let appName = "Passepartout"
 

Passepartout/Launcher/Constants/Constants+Launcher.swift

@@ -27,7 +27,7 @@ import Foundation
 
 extension Constants {
     enum Launcher {
-        static let appId = "com.algoritmico.ios.Passepartout"
+        static let appId: String = bundleConfig("app_id")
 
         private static let appPath: String = {
             let path = Bundle.main.bundlePath as NSString

Passepartout/Launcher/Info.plist

@@ -20,5 +20,10 @@
 	<string>$(EXECUTABLE_NAME)</string>
 	<key>CFBundlePackageType</key>
 	<string>$(PRODUCT_BUNDLE_PACKAGE_TYPE)</string>
+	<key>com.algoritmico.Passepartout.config</key>
+	<dict>
+		<key>app_id</key>
+		<string>$(CFG_APP_ID)</string>
+	</dict>
 </dict>
 </plist>