[Vertex AI] Add HarmBlockMethod enum and method property

Author: andrewheard

FirebaseVertexAI/Sources/Safety.swift

@@ -108,9 +108,24 @@ public struct SafetySetting {
     let rawValue: String
   }
 
+  /// The method of computing whether the ``SafetySetting/HarmBlockThreshold`` has been exceeded.
+  public struct HarmBlockMethod: EncodableProtoEnum, Sendable {
+    enum Kind: String {
+      case severity = "SEVERITY"
+      case probability = "PROBABILITY"
+    }
+
+    public static let severity = HarmBlockMethod(kind: .severity)
+
+    public static let probability = HarmBlockMethod(kind: .probability)
+
+    let rawValue: String
+  }
+
   enum CodingKeys: String, CodingKey {
     case harmCategory = "category"
     case threshold
+    case method
   }
 
   /// The category this safety setting should be applied to.
@@ -119,10 +134,14 @@ public struct SafetySetting {
   /// The threshold describing what content should be blocked.
   public let threshold: HarmBlockThreshold
 
+  public let method: HarmBlockMethod?
+
   /// Initializes a new safety setting with the given category and threshold.
-  public init(harmCategory: HarmCategory, threshold: HarmBlockThreshold) {
+  public init(harmCategory: HarmCategory, threshold: HarmBlockThreshold,
+              method: HarmBlockMethod? = nil) {
     self.harmCategory = harmCategory
     self.threshold = threshold
+    self.method = method
   }
 }
 

FirebaseVertexAI/Tests/Integration/IntegrationTests.swift

@@ -30,8 +30,8 @@ final class IntegrationTests: XCTestCase {
     parts: "You are a friendly and helpful assistant."
   )
   let safetySettings = [
-    SafetySetting(harmCategory: .harassment, threshold: .blockLowAndAbove),
-    SafetySetting(harmCategory: .hateSpeech, threshold: .blockLowAndAbove),
+    SafetySetting(harmCategory: .harassment, threshold: .blockLowAndAbove, method: .probability),
+    SafetySetting(harmCategory: .hateSpeech, threshold: .blockLowAndAbove, method: .severity),
     SafetySetting(harmCategory: .sexuallyExplicit, threshold: .blockLowAndAbove),
     SafetySetting(harmCategory: .dangerousContent, threshold: .blockLowAndAbove),
     SafetySetting(harmCategory: .civicIntegrity, threshold: .blockLowAndAbove),
@@ -89,11 +89,11 @@ final class IntegrationTests: XCTestCase {
       modelName: "gemini-1.5-pro",
       generationConfig: generationConfig,
       safetySettings: [
-        SafetySetting(harmCategory: .harassment, threshold: .blockLowAndAbove),
+        SafetySetting(harmCategory: .harassment, threshold: .blockLowAndAbove, method: .severity),
         SafetySetting(harmCategory: .hateSpeech, threshold: .blockMediumAndAbove),
         SafetySetting(harmCategory: .sexuallyExplicit, threshold: .blockOnlyHigh),
         SafetySetting(harmCategory: .dangerousContent, threshold: .blockNone),
-        SafetySetting(harmCategory: .civicIntegrity, threshold: .off),
+        SafetySetting(harmCategory: .civicIntegrity, threshold: .off, method: .probability),
       ],
       toolConfig: .init(functionCallingConfig: .auto()),
       systemInstruction: systemInstruction