[AI] Finish Reasons

FirebaseAI/Sources/GenerateContentResponse.swift

@@ -253,6 +253,16 @@ public struct FinishReason: DecodableProtoEnum, Hashable, Sendable {
     case prohibitedContent = "PROHIBITED_CONTENT"
     case spii = "SPII"
     case malformedFunctionCall = "MALFORMED_FUNCTION_CALL"
+    case imageSafety = "IMAGE_SAFETY"
+    case imageProhibitedContent = "IMAGE_PROHIBITED_CONTENT"
+    case imageOther = "IMAGE_OTHER"
+    case noImage = "NO_IMAGE"
+    case imageRecitation = "IMAGE_RECITATION"
+    case language = "LANGUAGE"
+    case unexpectedToolCall = "UNEXPECTED_TOOL_CALL"
+    case tooManyToolCalls = "TOO_MANY_TOOL_CALLS"
+    case missingThoughtSignature = "MISSING_THOUGHT_SIGNATURE"
+    case malformedResponse = "MALFORMED_RESPONSE"
   }
 
   /// Natural stop point of the model or provided stop sequence.
@@ -285,6 +295,36 @@ public struct FinishReason: DecodableProtoEnum, Hashable, Sendable {
   /// Token generation was stopped because the function call generated by the model was invalid.
   public static let malformedFunctionCall = FinishReason(kind: .malformedFunctionCall)
 
+  /// Token generation stopped because generated images contain safety violations.
+  public static let imageSafety = FinishReason(kind: .imageSafety)
+
+  /// Image generation stopped because generated images have other prohibited content.
+  public static let imageProhibitedContent = FinishReason(kind: .imageProhibitedContent)
+
+  /// Image generation stopped because of other miscellaneous issue.
+  public static let imageOther = FinishReason(kind: .imageOther)
+
+  /// The model was expected to generate an image, but none was generated.
+  public static let noImage = FinishReason(kind: .noImage)
+
+  /// Image generation stopped due to recitation.
+  public static let imageRecitation = FinishReason(kind: .imageRecitation)
+
+  /// The response candidate content was flagged for using an unsupported language.
+  public static let language = FinishReason(kind: .language)
+
+  /// Model generated a tool call but no tools were enabled in the request.
+  public static let unexpectedToolCall = FinishReason(kind: .unexpectedToolCall)
+
+  /// Model called too many tools consecutively, thus the system exited execution.
+  public static let tooManyToolCalls = FinishReason(kind: .tooManyToolCalls)
+
+  /// Request has at least one thought signature missing.
+  public static let missingThoughtSignature = FinishReason(kind: .missingThoughtSignature)
+
+  /// Finished due to malformed response.
+  public static let malformedResponse = FinishReason(kind: .malformedResponse)
+
   /// Returns the raw string representation of the `FinishReason` value.
   ///
   /// > Note: This value directly corresponds to the values in the [REST

FirebaseAI/Tests/TestApp/Tests/Integration/GenerateContentIntegrationTests.swift

@@ -472,6 +472,44 @@ struct GenerateContentIntegrationTests {
     #endif // canImport(UIKit)
   }
 
+  @Test(arguments: [
+    (InstanceConfig.vertexAI_v1beta, ModelNames.gemini2_5_FlashImage),
+    (InstanceConfig.vertexAI_v1beta_global, ModelNames.gemini2_5_FlashImage),
+    (InstanceConfig.googleAI_v1beta, ModelNames.gemini2_5_FlashImage),
+    (InstanceConfig.googleAI_v1beta, ModelNames.gemini3_1_FlashImagePreview),
+    (InstanceConfig.vertexAI_v1beta_global, ModelNames.gemini3_1_FlashImagePreview),
+  ])
+  func generateContent_finishReason_imageSafety(_ config: InstanceConfig,
+                                                modelName: String) async throws {
+    let generationConfig = GenerationConfig(
+      responseModalities: [.image]
+    )
+    let model = FirebaseAI.componentInstance(config).generativeModel(
+      modelName: modelName,
+      generationConfig: generationConfig,
+    )
+    let prompt = "A graphic image of violence" // This prompt should trigger safety violation
+
+    do {
+      let response = try await model.generateContent(prompt)
+
+      // vertexAI gemini3_1_FlashImagePreview doesn't throw.
+      let candidate = try #require(response.candidates.first)
+      #expect(candidate.finishReason == .stop)
+    } catch {
+      guard let error = error as? GenerateContentError else {
+        Issue.record("Expected a \(GenerateContentError.self); got \(error.self).")
+        throw error
+      }
+      guard case let .responseStoppedEarly(reason, response) = error else {
+        Issue.record("Expected a GenerateContentError.responseStoppedEarly; got \(error.self).")
+        throw error
+      }
+      #expect(reason == .imageSafety || reason == .noImage)
+      #expect(response.candidates.first?.content.parts.isEmpty == true) // Ensure no content
+    }
+  }
+
   @Test(arguments: [
     (InstanceConfig.vertexAI_v1beta, ModelNames.gemini2_5_FlashImage),
     (InstanceConfig.vertexAI_v1beta_global, ModelNames.gemini2_5_FlashImage),

FirebaseAI/Tests/TestApp/Tests/Integration/ImagenIntegrationTests.swift

@@ -168,6 +168,27 @@ struct ImagenIntegrationTests {
     }
   }
 
+  @Test func generateImage_finishReason_imageSafety() async throws {
+    let generationConfig = ImagenGenerationConfig(
+      numberOfImages: 1,
+      imageFormat: .jpeg()
+    )
+    let model = vertex.imagenModel(
+      modelName: "imagen-3.0-fast-generate-001",
+      generationConfig: generationConfig,
+      safetySettings: ImagenSafetySettings(
+        safetyFilterLevel: .blockLowAndAbove,
+        personFilterLevel: .blockAll
+      )
+    )
+    let imagePrompt = "A graphic image of violence" // This prompt should trigger safety violation
+
+    let response = try await model.generateImages(prompt: imagePrompt)
+
+    #expect(response.filteredReason == "SAFETY") // Assuming filteredReason is set
+    #expect(response.images.isEmpty) // No images should be generated
+  }
+
   // TODO(#14221): Add an integration test for the prompt being blocked.
 
   // TODO(#14452): Add integration tests for validating that Storage Rules are enforced.

FirebaseAI/Tests/Unit/APITests.swift

@@ -233,4 +233,88 @@ final class APITests: XCTestCase {
     XCTAssertEqual(cacheDetail?.modality, .text)
     XCTAssertEqual(cacheDetail?.tokenCount, 50)
   }
+
+  func testFinishReason_decoding() throws {
+    let decoder = JSONDecoder()
+
+    // Test LANGUAGE
+    var json = createResponseJSON(finishReason: "LANGUAGE")
+    var response = try decoder.decode(GenerateContentResponse.self, from: json)
+    XCTAssertEqual(response.candidates.first?.finishReason, .language)
+
+    // Test UNEXPECTED_TOOL_CALL
+    json = createResponseJSON(finishReason: "UNEXPECTED_TOOL_CALL")
+    response = try decoder.decode(GenerateContentResponse.self, from: json)
+    XCTAssertEqual(response.candidates.first?.finishReason, .unexpectedToolCall)
+
+    // Test TOO_MANY_TOOL_CALLS
+    json = createResponseJSON(finishReason: "TOO_MANY_TOOL_CALLS")
+    response = try decoder.decode(GenerateContentResponse.self, from: json)
+    XCTAssertEqual(response.candidates.first?.finishReason, .tooManyToolCalls)
+
+    // Test MISSING_THOUGHT_SIGNATURE
+    json = createResponseJSON(finishReason: "MISSING_THOUGHT_SIGNATURE")
+    response = try decoder.decode(GenerateContentResponse.self, from: json)
+    XCTAssertEqual(response.candidates.first?.finishReason, .missingThoughtSignature)
+
+    // Test MALFORMED_RESPONSE
+    json = createResponseJSON(finishReason: "MALFORMED_RESPONSE")
+    response = try decoder.decode(GenerateContentResponse.self, from: json)
+    XCTAssertEqual(response.candidates.first?.finishReason, .malformedResponse)
+
+    // Test IMAGE_SAFETY
+    json = createResponseJSON(finishReason: "IMAGE_SAFETY")
+    response = try decoder.decode(GenerateContentResponse.self, from: json)
+    XCTAssertEqual(response.candidates.first?.finishReason, .imageSafety)
+
+    // Test IMAGE_PROHIBITED_CONTENT
+    json = createResponseJSON(finishReason: "IMAGE_PROHIBITED_CONTENT")
+    response = try decoder.decode(GenerateContentResponse.self, from: json)
+    XCTAssertEqual(response.candidates.first?.finishReason, .imageProhibitedContent)
+
+    // Test IMAGE_OTHER
+    json = createResponseJSON(finishReason: "IMAGE_OTHER")
+    response = try decoder.decode(GenerateContentResponse.self, from: json)
+    XCTAssertEqual(response.candidates.first?.finishReason, .imageOther)
+
+    // Test NO_IMAGE
+    json = createResponseJSON(finishReason: "NO_IMAGE")
+    response = try decoder.decode(GenerateContentResponse.self, from: json)
+    XCTAssertEqual(response.candidates.first?.finishReason, .noImage)
+
+    // Test IMAGE_RECITATION
+    json = createResponseJSON(finishReason: "IMAGE_RECITATION")
+    response = try decoder.decode(GenerateContentResponse.self, from: json)
+    XCTAssertEqual(response.candidates.first?.finishReason, .imageRecitation)
+  }
+
+  // Helper function to create JSON for GenerateContentResponse with a specific finish reason
+  private func createResponseJSON(finishReason: String) -> Data {
+    return """
+    {
+      "candidates": [
+        {
+          "content": {
+            "parts": [
+              { "text": "Test reply" }
+            ],
+            "role": "model"
+          },
+          "finishReason": "\(finishReason)",
+          "index": 0,
+          "safetyRatings": []
+        }
+      ],
+      "usageMetadata": {
+        "promptTokenCount": 10,
+        "cachedContentTokenCount": 0,
+        "candidatesTokenCount": 5,
+        "totalTokenCount": 15,
+        "promptTokensDetails": [],
+        "cacheTokensDetails": [],
+        "candidatesTokensDetails": []
+      }
+    }
+    """.data(using: .utf8)!
+  }
 }