Add Dark theme support

Example/.prefire.yml

@@ -9,6 +9,7 @@ test_configuration:
       - UIKit
       - Foundation
   - use_grouped_snapshots: false
+  - record_in_dark_mode: true
 
 playbook_configuration:
   - imports:

Example/Shared/Assets.xcassets/gradientEnd.colorset/Contents.json

@@ -0,0 +1,38 @@
+{
+  "colors" : [
+    {
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0x82",
+          "green" : "0x00",
+          "red" : "0x4B"
+        }
+      },
+      "idiom" : "universal"
+    },
+    {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0x00",
+          "green" : "0x80",
+          "red" : "0x00"
+        }
+      },
+      "idiom" : "universal"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

Example/Shared/Assets.xcassets/gradientStart.colorset/Contents.json

@@ -0,0 +1,38 @@
+{
+  "colors" : [
+    {
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0x00",
+          "green" : "0x80",
+          "red" : "0x00"
+        }
+      },
+      "idiom" : "universal"
+    },
+    {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0x82",
+          "green" : "0x00",
+          "red" : "0x4B"
+        }
+      },
+      "idiom" : "universal"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

Example/Shared/Examples/AuthView.swift

@@ -58,6 +58,9 @@ struct AuthView_Preview: PreviewProvider, PrefireProvider {
         Group {
             AuthView(login: "", password: "")
 
+            AuthView(login: "", password: "")
+                .preferredColorScheme(.dark)
+
             AuthView(login: "FireUser", password: "FirePassword")
         }
         .previewUserStory(.auth)

Example/Shared/Examples/TestView.swift

@@ -8,7 +8,10 @@ struct TestView: View {
 
     var body: some View {
         VStack {
-            LinearGradient(gradient: Gradient(colors: [.green, .indigo]), startPoint: .top, endPoint: .bottom)
+            LinearGradient(gradient: Gradient(
+                colors: [Color("gradientStart", bundle: .module),
+                         Color("gradientEnd", bundle: .module)]),
+                           startPoint: .top, endPoint: .bottom)
                 .frame(height: 200)
 
             CircleImage()
@@ -74,15 +77,17 @@ struct TestViewWithoutState_Previews: PreviewProvider, PrefireProvider {
 
 struct GreenButton_Previews: PreviewProvider, PrefireProvider {
     static var previews: some View {
+
         Button("Apply", action: {})
-            .foregroundColor(.black)
+            .foregroundColor(.dynamicForegroundColor)
             .font(.title)
             .padding()
             .frame(maxWidth: .infinity)
             .frame(height: 68)
-            .background(Capsule().foregroundColor(.green.opacity(0.2)))
+            .background(Capsule().foregroundColor(.dynamicGreen))
             .previewLayout(.sizeThatFits)
             .previewUserStory("Buttons")
+
     }
 }
 
@@ -92,3 +97,33 @@ struct GreenButton_Previews: PreviewProvider, PrefireProvider {
         .snapshot(delay: 0.1, precision: 0.9)
         .previewUserStory(.auth)
 }
+
+extension Color {
+    static var dynamicForegroundColor: Color {
+        Color(UIColor.dynamicForegroundColor)
+    }
+
+    static var dynamicGreen: Color {
+        Color(UIColor.dynamicGreen)
+    }
+}
+
+extension UIColor {
+    static var dynamicForegroundColor: UIColor {
+        UIColor(dynamicProvider: { trait in
+            switch trait.userInterfaceStyle {
+                case .dark: return .white
+            default: return .black
+            }
+        })
+    }
+
+    static var dynamicGreen: UIColor {
+        UIColor(dynamicProvider: { trait in
+            switch trait.userInterfaceStyle {
+            case .dark: return UIColor.green.withAlphaComponent(0.8)
+            default: return UIColor.green.withAlphaComponent(0.2)
+            }
+        })
+    }
+}

Example/Shared/Examples/UIKitView.swift

@@ -3,12 +3,12 @@ import Prefire
 
 #Preview {
     let view = UIView(frame: .init(origin: .zero, size: .init(width: 100, height: 100)))
-    view.backgroundColor = .red
+    view.backgroundColor = UIColor.dynamicGreen
     return view
 }
 
 #Preview {
     let viewController = UIViewController()
-    viewController.view.backgroundColor = .green
+    viewController.view.backgroundColor = .dynamicForegroundColor
     return viewController
 }

PrefireExecutable/Sources/PrefireCore/PrefireGenerator.swift

@@ -15,7 +15,8 @@ public enum PrefireGenerator {
         inlineTemplate: String,
         defaultEnabled: Bool,
         cacheDir: Path? = nil,
-        useGroupedSnapshots: Bool
+        useGroupedSnapshots: Bool,
+        recordInDarkMode: Bool
     ) async throws {
         startTime = Date()
 

PrefireExecutable/Sources/PrefireCore/Templates/PreviewTestsTemplate.swift

@@ -51,6 +51,12 @@ import SnapshotTesting
             if let failure = assertSnapshots(for: PrefireSnapshot(preview, device: preview.device?.snapshotDevice() ?? deviceConfig)) {
                 XCTFail(failure)
             }
+
+    {% if argument.recordInDarkMode == "true" %}
+            if let failure = assertSnapshots(for: PrefireSnapshot(preview, device: preview.device?.snapshotDevice() ?? deviceConfig, isDark: true)) {
+                XCTFail(failure)
+            }
+    {% endif %}
         }
     }
     {%- if not forloop.last %}
@@ -83,6 +89,13 @@ import SnapshotTesting
         if let failure = assertSnapshots(for: PrefireSnapshot(preview(), name: "{{ macroModel.displayName }}", isScreen: isScreen, device: deviceConfig)) {
             XCTFail(failure)
         }
+
+    {% if argument.recordInDarkMode == "true" %}
+        if let failure = assertSnapshots(for: PrefireSnapshot(preview(), name: "{{ macroModel.displayName }}", isScreen: isScreen, device: deviceConfig, isDark: true)) {
+            XCTFail(failure)
+        }
+    {% endif %}
+
     }
     {%- if not forloop.last %}
 

PrefireExecutable/Sources/prefire/Commands/Playbook/GeneratePlaybookCommand.swift

@@ -53,7 +53,8 @@ enum GeneratePlaybookCommand {
             inlineTemplate: try options.template?.read(.utf8) ?? EmbeddedTemplates.previewModels,
             defaultEnabled: options.previewDefaultEnabled,
             cacheDir: options.cacheBasePath,
-            useGroupedSnapshots: true // Playbooks are always grouped
+            useGroupedSnapshots: true, // Playbooks are always grouped
+            recordInDarkMode: false
         )
     }
 

PrefireExecutable/Sources/prefire/Commands/Tests/GenerateTestsCommand.swift

@@ -22,6 +22,7 @@ struct GeneratedTestsOptions {
     var imports: [String]?
     var testableImports: [String]?
     var useGroupedSnapshots: Bool
+    var recordInDarkMode: Bool
 
     init(
         target: String?,
@@ -57,6 +58,7 @@ struct GeneratedTestsOptions {
         snapshotDevices = config?.tests.snapshotDevices
         imports = config?.tests.imports
         testableImports = config?.tests.testableImports
+        self.recordInDarkMode = config?.tests.recordInDarkMode ?? false
     }
 }
 
@@ -77,6 +79,7 @@ enum GenerateTestsCommand {
         static let testableImports = "testableImports"
         static let previewsMacros = "previewsMacros"
         static let previewsMacrosDict = "previewsMacrosDict"
+        static let recordInDarkMode = "recordInDarkMode"
     }
 
     static func run(_ options: GeneratedTestsOptions) async throws {
@@ -88,7 +91,8 @@ enum GenerateTestsCommand {
             inlineTemplate: try options.template?.read(.utf8) ?? EmbeddedTemplates.previewTests,
             defaultEnabled: options.prefireEnabledMarker,
             cacheDir: options.cacheBasePath,
-            useGroupedSnapshots: options.useGroupedSnapshots
+            useGroupedSnapshots: options.useGroupedSnapshots,
+            recordInDarkMode: options.recordInDarkMode
         )
     }
 
@@ -115,6 +119,7 @@ enum GenerateTestsCommand {
             Keys.testableImports: options.testableImports as? NSArray,
             Keys.mainTarget: options.target as? NSString,
             Keys.file: snapshotOutput?.string as? NSString,
+            Keys.recordInDarkMode: "\(options.recordInDarkMode)" as NSString,
         ].filter({ $0.value != nil }) as? [String: NSObject] ?? [:]
     }
 }

PrefireExecutable/Sources/prefire/Config/Config.swift

@@ -24,6 +24,7 @@ struct TestsConfig {
     var imports: [String]?
     var testableImports: [String]?
     var useGroupedSnapshots: Bool?
+    var recordInDarkMode: Bool?
 
     enum CodingKeys: String, CodingKey {
         case target = "target"
@@ -38,6 +39,7 @@ struct TestsConfig {
         case imports = "imports"
         case testableImports = "testable_imports"
         case useGroupedSnapshots = "use_grouped_snapshots"
+        case recordInDarkMode = "record_in_dark_mode"
     }
 }
 

PrefireExecutable/Sources/prefire/Config/ConfigDecoder.swift

@@ -72,6 +72,8 @@ final class ConfigDecoder {
             config.tests.testTargetPath = getValue(from: components.last, env: env)
         case .useGroupedSnapshots:
             config.tests.useGroupedSnapshots = getValue(from: components.last, env: env) == "true"
+        case .recordInDarkMode:
+            config.tests.recordInDarkMode = getValue(from: components.last, env: env) == "true"
         }
     }
 

PrefireExecutable/Tests/PrefireTests/PrefireGeneratorTests.swift

@@ -17,7 +17,8 @@ final class PrefireGeneratorTests: XCTestCase {
                 arguments: args,
                 inlineTemplate: template,
                 defaultEnabled: true,
-                useGroupedSnapshots: true
+                useGroupedSnapshots: true,
+                recordInDarkMode: false
             )
         } catch {
             XCTFail("Unexpected error thrown: \(error)")
@@ -39,7 +40,8 @@ final class PrefireGeneratorTests: XCTestCase {
             inlineTemplate: template,
             defaultEnabled: true,
             cacheDir: cache,
-            useGroupedSnapshots: true
+            useGroupedSnapshots: true,
+            recordInDarkMode: false
         )
 
         let result = try output.read(.utf8)
@@ -63,7 +65,8 @@ final class PrefireGeneratorTests: XCTestCase {
             inlineTemplate: template,
             defaultEnabled: true,
             cacheDir: cache,
-            useGroupedSnapshots: false // Test ungrouped generation
+            useGroupedSnapshots: false, // Test ungrouped generation
+            recordInDarkMode: false
         )
 
         // Should generate file with name based on the fixture file
@@ -90,7 +93,8 @@ final class PrefireGeneratorTests: XCTestCase {
             inlineTemplate: template,
             defaultEnabled: true,
             cacheDir: cache,
-            useGroupedSnapshots: true // Test grouped generation
+            useGroupedSnapshots: true, // Test grouped generation
+            recordInDarkMode: false
         )
 
         // Should generate file with Preview as class name for grouped snapshots
@@ -116,7 +120,8 @@ final class PrefireGeneratorTests: XCTestCase {
             inlineTemplate: template,
             defaultEnabled: true,
             cacheDir: cache,
-            useGroupedSnapshots: false // Test ungrouped generation
+            useGroupedSnapshots: false, // Test ungrouped generation
+            recordInDarkMode: false
         )
 
         // Should generate file with source file name as class name for ungrouped snapshots