Define which interface style the test should be run on from launch ar…

…guments (#8)

Sources/SnapshotTestCase/Models/LaunchEnvironment.swift

@@ -7,6 +7,7 @@ enum LaunchEnvironment {
         static let tolerance: String = "snapshotTolerance"
         static let renderOffsetY: String = "snapshotRenderOffsetY"
         static let renderScale: String = "snapshotRenderScale"
+        static let interfaceStyle: String = "snapshotInterfaceStyle"
         static let recordMode: String = "-RecordingSnapshot"
     }
 
@@ -42,4 +43,11 @@ enum LaunchEnvironment {
         }
         return Double(renderScale) ?? 1
     }
+
+    static var interfaceStyle: InterfaceStyle? {
+        guard let rawValue = ProcessInfo.processInfo.environment[Key.interfaceStyle] else {
+            return nil
+        }
+        return InterfaceStyle(rawValue: rawValue)
+    }
 }

Sources/SnapshotTestCase/Snapshot.swift

@@ -27,12 +27,14 @@ public class Snapshot {
     let failurePath: String
     let recordMode: Bool
     let tolerance: Double
+    let interfaceStyle: InterfaceStyle?
 
     init() {
         self.referencePath = LaunchEnvironment.referencePath
         self.failurePath = LaunchEnvironment.failurePath
         self.recordMode = LaunchEnvironment.recordMode
         self.tolerance = LaunchEnvironment.tolerance
+        self.interfaceStyle = LaunchEnvironment.interfaceStyle
     }
 
     func verify(testCase: TestCase, with config: SnapshotConfig) async throws {
@@ -52,6 +54,9 @@ public class Snapshot {
     }
 
     func verify(testCase: TestCase, with config: SnapshotConfig.Config) async throws {
+        if let interfaceStyle, interfaceStyle != config.interfaceStyle {
+            return
+        }
         if recordMode {
             return try await record(testCase: testCase, with: config)
         }