Add test

Author: JeroenWeener

packages/image_picker/image_picker_android/android/src/main/java/io/flutter/plugins/imagepicker/ImagePickerCache.java

@@ -98,8 +98,7 @@ void saveResult(
 
     SharedPreferences.Editor editor = prefs.edit();
     if (path != null) {
-      Set<String> imageSet = new HashSet<>();
-      imageSet.addAll(path);
+      Set<String> imageSet = new HashSet<>(path);
       editor.putStringSet(FLUTTER_IMAGE_PICKER_IMAGE_PATH_KEY, imageSet);
     }
     if (errorCode != null) {

packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImagePickerCacheTest.java

@@ -7,6 +7,7 @@
 import static io.flutter.plugins.imagepicker.ImagePickerCache.SHARED_PREFERENCES_NAME;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.core.IsEqual.equalTo;
+import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
@@ -115,4 +116,11 @@ public void imageCache_shouldBeAbleToSetAndGetQuality() {
         (int) resultMapWithDefaultQuality.get(ImagePickerCache.MAP_KEY_IMAGE_QUALITY);
     assertThat(defaultImageQuality, equalTo(100));
   }
+
+  @Test
+  public void imageCache_shouldNotThrowIfPathIsNullInSaveResult() {
+    final ImagePickerCache cache = new ImagePickerCache(mockActivity);
+    cache.saveResult(null, "errorCode", "errorMessage");
+      assertTrue("No exception thrown when ImagePickerCache.saveResult() was passed a null path", true);
+  }
 }