fix: tolerate empty deepLinkData object in InstallResponse

CHANGELOG.md

@@ -1,3 +1,7 @@
+## Unreleased
+
+* **Fixed:** `InstallResponse.fromJson` no longer throws when the backend returns `deepLinkData: {}` for an organic (unattributed) install, which surfaced as an error out of `initialize()`. An empty — or otherwise unusable — `deepLinkData` object is now treated as "no deep link" (`null`), the same as an explicit `null`.
+
 ## 0.2.1
 
 * **URL parameters are now delivered on a direct open** (app already installed), not just after a deferred install. A link shared as `?slug=titanic` previously returned only the link's stored configuration on a direct open, because `_resolveUrl` discarded the local parse of the tapped URL. `customParameters` now carries both, with URL values winning on a collision — the same precedence the server applies on the deferred path. `linkId`, `deepLinkPath`, `appScheme`, the store URLs and `utmParameters` remain server-provided.

lib/models/install_response.dart

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'package:json_annotation/json_annotation.dart';
+import '../link_forty_logger.dart';
 import 'deep_link_data.dart';
 
 part 'install_response.g.dart';
@@ -23,6 +24,7 @@ class InstallResponse {
   final List<String> matchedFactors;
 
   /// Deep link data if attributed, null if organic
+  @JsonKey(fromJson: _deepLinkDataFromJson)
   final DeepLinkData? deepLinkData;
 
   /// Creates an install response
@@ -83,4 +85,23 @@ class InstallResponse {
   static int _listHashCode(List<String> list) {
     return list.fold(0, (hash, item) => hash ^ item.hashCode);
   }
+
+  /// Parses the `deepLinkData` field of an install response.
+  ///
+  /// Organic (unattributed) installs come back as `deepLinkData: {}` rather
+  /// than `null`, and an object without a `shortCode` carries no link to route
+  /// to. Any payload that cannot be parsed is treated as "no deep link" so a
+  /// missing or unexpected field can never fail the whole install response —
+  /// that would abort SDK initialization for every organic install.
+  static DeepLinkData? _deepLinkDataFromJson(Object? json) {
+    if (json is! Map<String, dynamic>) return null;
+    try {
+      return DeepLinkData.fromJson(json);
+    } catch (e) {
+      LinkFortyLogger.log(
+        'Ignoring undecodable deepLinkData in install response: $e',
+      );
+      return null;
+    }
+  }
 }

test/models/install_response_test.dart

@@ -33,6 +33,80 @@ void main() {
       expect(response.deepLinkData, isNull);
     });
 
+    // The backend returns `deepLinkData: {}` (not null) for organic installs.
+    test('treats an empty deepLinkData object as no deep link', () {
+      final response = InstallResponse.fromJson({
+        'installId': 'inst_456',
+        'attributed': false,
+        'confidenceScore': 0.0,
+        'matchedFactors': <String>[],
+        'deepLinkData': <String, dynamic>{},
+      });
+
+      expect(response.installId, 'inst_456');
+      expect(response.attributed, isFalse);
+      expect(response.deepLinkData, isNull);
+    });
+
+    test('treats a null deepLinkData as no deep link', () {
+      final response = InstallResponse.fromJson({
+        'installId': 'inst_456',
+        'attributed': false,
+        'confidenceScore': 0.0,
+        'matchedFactors': <String>[],
+        'deepLinkData': null,
+      });
+
+      expect(response.deepLinkData, isNull);
+    });
+
+    // A deep link with no short code can't be routed to, so it is not worth
+    // failing the whole response over.
+    test('treats deepLinkData without a shortCode as no deep link', () {
+      final response = InstallResponse.fromJson({
+        'installId': 'inst_456',
+        'attributed': false,
+        'confidenceScore': 0.0,
+        'matchedFactors': <String>[],
+        'deepLinkData': {'iosUrl': 'myapp://product/456'},
+      });
+
+      expect(response.deepLinkData, isNull);
+    });
+
+    test('deserializes an attributed response with deep link data', () {
+      final response = InstallResponse.fromJson({
+        'installId': 'inst_789',
+        'attributed': true,
+        'confidenceScore': 85,
+        'matchedFactors': ['ip', 'ua'],
+        'deepLinkData': {
+          'shortCode': 'abc123',
+          'iosUrl': 'myapp://product/456',
+          'deepLinkPath': '/product/456',
+          'clickedAt': '2026-01-15T10:30:00Z',
+        },
+      });
+
+      expect(response.attributed, isTrue);
+      expect(response.confidenceScore, 85);
+      expect(response.deepLinkData?.shortCode, 'abc123');
+      expect(response.deepLinkData?.iosURL, 'myapp://product/456');
+      expect(response.deepLinkData?.deepLinkPath, '/product/456');
+      expect(response.deepLinkData?.clickedAt, isNotNull);
+    });
+
+    test('throws when a required field is missing', () {
+      expect(
+        () => InstallResponse.fromJson({
+          'attributed': false,
+          'confidenceScore': 0.0,
+          'matchedFactors': <String>[],
+        }),
+        throwsA(isA<TypeError>()),
+      );
+    });
+
     test('equality works correctly', () {
       final res1 = InstallResponse(
         installId: '1',