[image_picker] Switch unit tests to mock plaform implementation

packages/image_picker/image_picker/CHANGELOG.md

@@ -1,3 +1,10 @@
+## 0.8.5+3
+
+* Adds argument error assertions to the app-facing package, to ensure
+  consistency across platform implementations.
+* Updates tests to use a mock platform instead of relying on default
+  method channel implementation internals.
+
 ## 0.8.5+2
 
 * Minor fixes for new analysis options.

packages/image_picker/image_picker/lib/image_picker.dart

@@ -207,6 +207,17 @@ class ImagePicker {
     int? imageQuality,
     CameraDevice preferredCameraDevice = CameraDevice.rear,
   }) {
+    if (imageQuality != null && (imageQuality < 0 || imageQuality > 100)) {
+      throw ArgumentError.value(
+          imageQuality, 'imageQuality', 'must be between 0 and 100');
+    }
+    if (maxWidth != null && maxWidth < 0) {
+      throw ArgumentError.value(maxWidth, 'maxWidth', 'cannot be negative');
+    }
+    if (maxHeight != null && maxHeight < 0) {
+      throw ArgumentError.value(maxHeight, 'maxHeight', 'cannot be negative');
+    }
+
     return platform.getImage(
       source: source,
       maxWidth: maxWidth,
@@ -245,6 +256,17 @@ class ImagePicker {
     double? maxHeight,
     int? imageQuality,
   }) {
+    if (imageQuality != null && (imageQuality < 0 || imageQuality > 100)) {
+      throw ArgumentError.value(
+          imageQuality, 'imageQuality', 'must be between 0 and 100');
+    }
+    if (maxWidth != null && maxWidth < 0) {
+      throw ArgumentError.value(maxWidth, 'maxWidth', 'cannot be negative');
+    }
+    if (maxHeight != null && maxHeight < 0) {
+      throw ArgumentError.value(maxHeight, 'maxHeight', 'cannot be negative');
+    }
+
     return platform.getMultiImage(
       maxWidth: maxWidth,
       maxHeight: maxHeight,

packages/image_picker/image_picker/pubspec.yaml

@@ -3,7 +3,7 @@ description: Flutter plugin for selecting images from the Android and iOS image
   library, and taking new pictures with the camera.
 repository: https://github.com/flutter/plugins/tree/main/packages/image_picker/image_picker
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+image_picker%22
-version: 0.8.5+2
+version: 0.8.5+3
 
 environment:
   sdk: ">=2.14.0 <3.0.0"
@@ -28,6 +28,8 @@ dependencies:
   image_picker_platform_interface: ^2.3.0
 
 dev_dependencies:
+  build_runner: ^2.1.10
+  cross_file: ^0.3.1+1 # Mockito generates a direct include.
   flutter_test:
     sdk: flutter
   mockito: ^5.0.0