createMockImageHttpClient function

Implementation

MockHttpClient createMockImageHttpClient() {
  final client = MockHttpClient();
  final request = MockHttpClientRequest();
  final response = MockHttpClientResponse();
  final headers = MockHttpHeaders();

  when(client.getUrl(any))
      .thenAnswer((_) => Future<HttpClientRequest>.value(request));
  when(request.headers).thenReturn(headers);
  when(request.close())
      .thenAnswer((_) => Future<HttpClientResponse>.value(response));
  when(response.compressionState)
      .thenReturn(HttpClientResponseCompressionState.notCompressed);
  when(response.contentLength).thenReturn(image.length);
  when(response.statusCode).thenReturn(HttpStatus.ok);
  when(response.listen(
    any,
    onError: anyNamed("onError"),
    onDone: anyNamed("onDone"),
    cancelOnError: anyNamed("cancelOnError"),
  )).thenAnswer((invocation) {
    final onData =
        invocation.positionalArguments[0] as void Function(List<int>);
    final onDone = invocation.namedArguments[#onDone] as void Function()?;
    final onError = invocation.namedArguments[#onError] as Function?;
    final cancelOnError = invocation.namedArguments[#cancelOnError] as bool?;

    return Stream<List<int>>.fromIterable(<List<int>>[image]).listen(onData,
        onDone: onDone, onError: onError, cancelOnError: cancelOnError);
  });

  return client;
}