Add mocktail dev dependency and fix test state leak

Address PR review comments:
- Add mocktail and flutter_test to dev_dependencies in pubspec.yaml
- Add tearDown to reset AppState.instance between tests

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pubspec.lock

@@ -65,6 +65,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.13.0"
+  boolean_selector:
+    dependency: transitive
+    description:
+      name: boolean_selector
+      sha256: "8aab1771e1243a5063b8b0ff68042d67334e3feab9e95b9490f9a6ebf73b42ea"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.1.2"
   characters:
     dependency: transitive
     description:
@@ -161,6 +169,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.2.3"
+  fake_async:
+    dependency: transitive
+    description:
+      name: fake_async
+      sha256: "5368f224a74523e8d2e7399ea1638b37aecfca824a3cc4dfdf77bf1fa905ac44"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.3.3"
   ffi:
     dependency: transitive
     description:
@@ -310,6 +326,11 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.2.0"
+  flutter_test:
+    dependency: "direct dev"
+    description: flutter
+    source: sdk
+    version: "0.0.0"
   flutter_web_auth_2:
     dependency: "direct main"
     description:
@@ -443,6 +464,30 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.9.1"
+  leak_tracker:
+    dependency: transitive
+    description:
+      name: leak_tracker
+      sha256: "33e2e26bdd85a0112ec15400c8cbffea70d0f9c3407491f672a2fad47915e2de"
+      url: "https://pub.dev"
+    source: hosted
+    version: "11.0.2"
+  leak_tracker_flutter_testing:
+    dependency: transitive
+    description:
+      name: leak_tracker_flutter_testing
+      sha256: "1dbc140bb5a23c75ea9c4811222756104fbcd1a27173f0c34ca01e16bea473c1"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.10"
+  leak_tracker_testing:
+    dependency: transitive
+    description:
+      name: leak_tracker_testing
+      sha256: "8d5a2d49f4a66b49744b23b018848400d23e54caf9463f4eb20df3eb8acb2eb1"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.2"
   linkify:
     dependency: transitive
     description:
@@ -467,6 +512,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.6.0"
+  matcher:
+    dependency: transitive
+    description:
+      name: matcher
+      sha256: dc58c723c3c24bf8d3e2d3ad3f2f9d7bd9cf43ec6feaa64181775e60190153f2
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.12.17"
   material_color_utilities:
     dependency: transitive
     description:
@@ -479,10 +532,10 @@ packages:
     dependency: transitive
     description:
       name: meta
-      sha256: e3641ec5d63ebf0d9b41bd43201a66e3fc79a65db5f61fc181f04cd27aab950c
+      sha256: "23f08335362185a5ea2ad3a4e597f1375e78bce8a040df5c600c8d3552ef2394"
       url: "https://pub.dev"
     source: hosted
-    version: "1.16.0"
+    version: "1.17.0"
   mgrs_dart:
     dependency: transitive
     description:
@@ -491,6 +544,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.0.0"
+  mocktail:
+    dependency: "direct dev"
+    description:
+      name: mocktail
+      sha256: "890df3f9688106f25755f26b1c60589a92b3ab91a22b8b224947ad041bf172d8"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.4"
   nested:
     dependency: transitive
     description:
@@ -760,6 +821,22 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.4.0"
+  stack_trace:
+    dependency: transitive
+    description:
+      name: stack_trace
+      sha256: "8b27215b45d22309b5cddda1aa2b19bdfec9df0e765f2de506401c071d38d1b1"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.12.1"
+  stream_channel:
+    dependency: transitive
+    description:
+      name: stream_channel
+      sha256: "969e04c80b8bcdf826f8f16579c7b14d780458bd97f56d107d3950fdbeef059d"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.1.4"
   string_scanner:
     dependency: transitive
     description:
@@ -784,6 +861,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.2.2"
+  test_api:
+    dependency: transitive
+    description:
+      name: test_api
+      sha256: ab2726c1a94d3176a45960b6234466ec367179b87dd74f1611adb1f3b5fb9d55
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.7.7"
   timezone:
     dependency: transitive
     description:
@@ -916,10 +1001,18 @@ packages:
     dependency: transitive
     description:
       name: vector_math
-      sha256: "80b3257d1492ce4d091729e3a67a60407d227c27241d6927be0130c98e741803"
+      sha256: d530bd74fea330e6e364cda7a85019c434070188383e1cd8d9777ee586914c5b
       url: "https://pub.dev"
     source: hosted
-    version: "2.1.4"
+    version: "2.2.0"
+  vm_service:
+    dependency: transitive
+    description:
+      name: vm_service
+      sha256: "45caa6c5917fa127b5dbcfbd1fa60b14e583afdc08bfc96dda38886ca252eb60"
+      url: "https://pub.dev"
+    source: hosted
+    version: "15.0.2"
   web:
     dependency: transitive
     description:

pubspec.yaml

@@ -38,6 +38,9 @@ dependencies:
   csv: ^6.0.0
 
 dev_dependencies:
+  flutter_test:
+    sdk: flutter
+  mocktail: ^1.0.4
   flutter_launcher_icons: ^0.14.4
   flutter_native_splash: ^2.4.6
 

test/services/deflock_tile_provider_test.dart

@@ -21,6 +21,11 @@ void main() {
       AppState.instance = mockAppState;
     });
 
+    tearDown(() {
+      // Reset to a clean mock so stubbed state doesn't leak to other tests
+      AppState.instance = MockAppState();
+    });
+
     test('creates image provider for tile coordinates', () {
       const coordinates = TileCoordinates(0, 0, 0);
       final options = TileLayer(