Update Citation decoding to handle optional values (google-gemini#135)

Author: andrewheard

Sources/GoogleAI/GenerateContentResponse.swift

@@ -174,7 +174,7 @@ public struct CitationMetadata: Decodable {
 
 /// A struct describing a source attribution.
 @available(iOS 15.0, macOS 11.0, macCatalyst 15.0, *)
-public struct Citation: Decodable {
+public struct Citation {
   /// The inclusive beginning of a sequence in a model response that derives from a cited source.
   public let startIndex: Int
 
@@ -297,3 +297,23 @@ extension PromptFeedback: Decodable {
     }
   }
 }
+
+// MARK: - Codable Conformances
+
+@available(iOS 15.0, macOS 11.0, macCatalyst 15.0, *)
+extension Citation: Decodable {
+  enum CodingKeys: CodingKey {
+    case startIndex
+    case endIndex
+    case uri
+    case license
+  }
+
+  public init(from decoder: any Decoder) throws {
+    let container = try decoder.container(keyedBy: CodingKeys.self)
+    startIndex = try container.decodeIfPresent(Int.self, forKey: .startIndex) ?? 0
+    endIndex = try container.decode(Int.self, forKey: .endIndex)
+    uri = try container.decode(String.self, forKey: .uri)
+    license = try container.decodeIfPresent(String.self, forKey: .license) ?? ""
+  }
+}

Tests/GoogleAITests/GenerativeModelTests.swift

@@ -104,12 +104,27 @@ final class GenerativeModelTests: XCTestCase {
     XCTAssertEqual(candidate.content.parts.count, 1)
     XCTAssertEqual(response.text, "Some information cited from an external source")
     let citationMetadata = try XCTUnwrap(candidate.citationMetadata)
-    XCTAssertEqual(citationMetadata.citationSources.count, 1)
-    let citationSource = try XCTUnwrap(citationMetadata.citationSources.first)
-    XCTAssertEqual(citationSource.uri, "https://www.example.com/some-citation")
-    XCTAssertEqual(citationSource.startIndex, 574)
-    XCTAssertEqual(citationSource.endIndex, 705)
-    XCTAssertEqual(citationSource.license, "")
+    XCTAssertEqual(citationMetadata.citationSources.count, 4)
+    let citationSource1 = try XCTUnwrap(citationMetadata.citationSources[0])
+    XCTAssertEqual(citationSource1.uri, "https://www.example.com/some-citation-1")
+    XCTAssertEqual(citationSource1.startIndex, 0)
+    XCTAssertEqual(citationSource1.endIndex, 128)
+    XCTAssertEqual(citationSource1.license, "")
+    let citationSource2 = try XCTUnwrap(citationMetadata.citationSources[1])
+    XCTAssertEqual(citationSource2.uri, "https://www.example.com/some-citation-2")
+    XCTAssertEqual(citationSource2.startIndex, 130)
+    XCTAssertEqual(citationSource2.endIndex, 265)
+    XCTAssertEqual(citationSource2.license, "")
+    let citationSource3 = try XCTUnwrap(citationMetadata.citationSources[2])
+    XCTAssertEqual(citationSource3.uri, "https://www.example.com/some-citation-3")
+    XCTAssertEqual(citationSource3.startIndex, 272)
+    XCTAssertEqual(citationSource3.endIndex, 431)
+    XCTAssertEqual(citationSource3.license, "")
+    let citationSource4 = try XCTUnwrap(citationMetadata.citationSources[3])
+    XCTAssertEqual(citationSource4.uri, "https://www.example.com/some-citation-4")
+    XCTAssertEqual(citationSource4.startIndex, 444)
+    XCTAssertEqual(citationSource4.endIndex, 630)
+    XCTAssertEqual(citationSource4.license, "mit")
   }
 
   func testGenerateContent_success_quoteReply() async throws {
@@ -724,9 +739,21 @@ final class GenerativeModelTests: XCTestCase {
 
     XCTAssertEqual(citations.count, 8)
     XCTAssertTrue(citations
-      .contains(where: { $0.startIndex == 574 && $0.endIndex == 705 && !$0.uri.isEmpty }))
+      .contains(where: {
+        $0.startIndex == 0 && $0.endIndex == 128 && !$0.uri.isEmpty && $0.license.isEmpty
+      }))
     XCTAssertTrue(citations
-      .contains(where: { $0.startIndex == 899 && $0.endIndex == 1026 && !$0.uri.isEmpty }))
+      .contains(where: {
+        $0.startIndex == 130 && $0.endIndex == 265 && !$0.uri.isEmpty && $0.license.isEmpty
+      }))
+    XCTAssertTrue(citations
+      .contains(where: {
+        $0.startIndex == 272 && $0.endIndex == 431 && !$0.uri.isEmpty && $0.license.isEmpty
+      }))
+    XCTAssertTrue(citations
+      .contains(where: {
+        $0.startIndex == 444 && $0.endIndex == 630 && !$0.uri.isEmpty && $0.license == "mit"
+      }))
   }
 
   func testGenerateContentStream_errorMidStream() async throws {