Flutter integration test - how to load a JSON file? - flutter

Question

I am writing a Flutter integration test with a mock client that returns a JSON response for each of the REST endpoints my app calls.
These JSON responses are stored in separate JSON files, but I am unable to access the files when the test is running.
I've tried loading the files by creating and reading a new file object. Flutter: how to load file for testing but it could never find the file.
I also tried putting my JSON files into assets. This worked, but also resulted in the test JSON files being bundled when I built the APK.
Simplified Mock Client:
MockClient integrationMockClient = MockClient((request) async {
switch (request.url.toString()) {
case 'https://staging.company.com/api/123':
return Response(readJsonfile('myJsonFile.json'), 200);
Simplified integration test main function - passes mock client in. test_driver/app.dart
void main() async {
enableFlutterDriverExtension();
final app = await initializeApp(
integrationMockClient
);
runApp(app);
}
When I try and read a file it can never find it. Possible because flutterDriver runs the 'real app' with no access to files stored in test directories.
How can I access a JSON file from an integration test without it being bundled in production code/APK?

Answer 1

I encountered similar issues accessing file resources using flutter driver for integration tests. What I did as a workaround was to parse the JSON response directly, instead of storing the JSON response as a file.
Here's a sample that you can try out. This uses https://jsonplaceholder.typicode.com as its endpoint sample.
test('Test http', () async {
final file = await http.get(Uri.parse('https://jsonplaceholder.typicode.com/albums/1'));
final json = jsonDecode(file.body.toString());
print('json contents: $json');
print('userId: ${json['userId']}');
final userId = json['userId'];
expect(userId, 1);
});

Answer 2

Put JSON into String variable, like this. const String objectJson = """{JSON}""";
Wrap your JSON with a triple quotation mark """
and use it on integration tests, instead of reading it from a file