public async Task SavePreferredCoin_GivenInValidCoinId_ShouldThrowException()
{
int coinId = 10;
var service = new UserPreferenceService(_context, _logger);
await Assert.ThrowsAsync <ArgumentException>(() => service.SavePreferredCoin(coinId));
}
public async Task <int> SavePreferredCoin([FromBody] int id)
{
var service = new UserPreferenceService(_context, _logger);
return(await service.SavePreferredCoin(id));
}