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public class LocationProvider : IDisposable
{
private readonly HttpClient _httpClient = new HttpClient();
// Gets location by query
public async Task<Location> GetLocationAsync(string locationQuery) { /* ... */ }
// Gets current location by IP
public async Task<Location> GetLocationAsync() { /* ... */ }
public void Dispose() => _httpClient.Dispose();
}
public class SolarCalculator : IDiposable
{
private readonly LocationProvider _locationProvider = new LocationProvider();
// Gets solar times for current location and specified date
public async Task<SolarTimes> GetSolarTimesAsync(DateTimeOffset date) { /* ... */ }
public void Dispose() => _locationProvider.Dispose();
}, -.
LocationProvider HttpClient, SolarCalculator, , LocationProvider, -, .
:
public interface ILocationProvider
{
Task<Location> GetLocationAsync(string locationQuery);
Task<Location> GetLocationAsync();
}
public class LocationProvider : ILocationProvider
{
private readonly HttpClient _httpClient;
public LocationProvider(HttpClient httpClient) =>
_httpClient = httpClient;
public async Task<Location> GetLocationAsync(string locationQuery) { /* ... */ }
public async Task<Location> GetLocationAsync() { /* ... */ }
}
public interface ISolarCalculator
{
Task<SolarTimes> GetSolarTimesAsync(DateTimeOffset date);
}
public class SolarCalculator : ISolarCalculator
{
private readonly ILocationProvider _locationProvider;
public SolarCalculator(ILocationProvider locationProvider) =>
_locationProvider = locationProvider;
public async Task<SolarTimes> GetSolarTimesAsync(DateTimeOffset date) { /* ... */ }
}LocationProvider SolarCalculator, . , IDisposable, , , .
, , , -. , (.. ).
-
SolarCalculator.GetSolarTimesAsync:
public class SolarCalculatorTests
{
[Fact]
public async Task GetSolarTimesAsync_ForKyiv_ReturnsCorrectSolarTimes()
{
// Arrange
var location = new Location(50.45, 30.52);
var date = new DateTimeOffset(2019, 11, 04, 00, 00, 00, TimeSpan.FromHours(+2));
var expectedSolarTimes = new SolarTimes(
new TimeSpan(06, 55, 00),
new TimeSpan(16, 29, 00)
);
var locationProvider = Mock.Of<ILocationProvider>(lp =>
lp.GetLocationAsync() == Task.FromResult(location)
);
var solarCalculator = new SolarCalculator(locationProvider);
// Act
var solarTimes = await solarCalculator.GetSolarTimesAsync(date);
// Assert
solarTimes.Should().BeEquivalentTo(expectedSolarTimes);
}
}, ,
SolarCalculator . - , , Method_Precondition_Result («__»).
Arrange,
ILocationProvider . GetLocationAsync() , .
,
ILocationProvider , , . , ( ).
, , -
GetSolarTimesAsync . , .
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public class SolarTimesSpecs
{
[Fact]
public async Task User_can_get_solar_times_automatically_for_their_location() { /* ... */ }
[Fact]
public async Task User_can_get_solar_times_during_periods_of_midnight_sun() { /* ... */ }
[Fact]
public async Task User_can_get_solar_times_if_their_location_cannot_be_resolved() { /* ... */ }
}, , , . , , .
, , — . ,
SolarCalculator - , .
, . , , CliWrap (xUnit ):
, . ( , , ..) ( , , JIRA, , ..)
, . open-source- readme, , .
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- ( ASP.NET Core)
, , , . , . - , . ASP.NET Core — -, , .
- IP . , Redis, .
, HTTP-, , . , . Docker, , .
, , -. , , GitHub.
IP,
LocationProvider, . GeoIP- IP-API:
public class LocationProvider
{
private readonly HttpClient _httpClient;
public LocationProvider(HttpClient httpClient) =>
_httpClient = httpClient;
public async Task<Location> GetLocationAsync(IPAddress ip)
{
// If IP is local, just don't pass anything (useful when running on localhost)
var ipFormatted = !ip.IsLocal() ? ip.MapToIPv4().ToString() : "";
var json = await _httpClient.GetJsonAsync($"http://ip-api.com/json/{ipFormatted}");
var latitude = json.GetProperty("lat").GetDouble();
var longitude = json.GetProperty("lon").GetDouble();
return new Location
{
Latitude = latitude,
Longitude = longitude
};
}
}, - . , ,
SolarCalculator :
public class SolarCalculator
{
private readonly LocationProvider _locationProvider;
public SolarCalculator(LocationProvider locationProvider) =>
_locationProvider = locationProvider;
private static TimeSpan CalculateSolarTimeOffset(Location location, DateTimeOffset instant,
double zenith, bool isSunrise)
{
/* ... */
// Algorithm omitted for brevity
/* ... */
}
public async Task<SolarTimes> GetSolarTimesAsync(Location location, DateTimeOffset date)
{
/* ... */
}
public async Task<SolarTimes> GetSolarTimesAsync(IPAddress ip, DateTimeOffset date)
{
var location = await _locationProvider.GetLocationAsync(ip);
var sunriseOffset = CalculateSolarTimeOffset(location, date, 90.83, true);
var sunsetOffset = CalculateSolarTimeOffset(location, date, 90.83, false);
var sunrise = date.ResetTimeOfDay().Add(sunriseOffset);
var sunset = date.ResetTimeOfDay().Add(sunsetOffset);
return new SolarTimes
{
Sunrise = sunrise,
Sunset = sunset
};
}
}- MVC, , :
[ApiController]
[Route("solartimes")]
public class SolarTimeController : ControllerBase
{
private readonly SolarCalculator _solarCalculator;
private readonly CachingLayer _cachingLayer;
public SolarTimeController(SolarCalculator solarCalculator, CachingLayer cachingLayer)
{
_solarCalculator = solarCalculator;
_cachingLayer = cachingLayer;
}
[HttpGet("by_ip")]
public async Task<IActionResult> GetByIp(DateTimeOffset? date)
{
var ip = HttpContext.Connection.RemoteIpAddress;
var cacheKey = $"{ip},{date}";
var cachedSolarTimes = await _cachingLayer.TryGetAsync<SolarTimes>(cacheKey);
if (cachedSolarTimes != null)
return Ok(cachedSolarTimes);
var solarTimes = await _solarCalculator.GetSolarTimesAsync(ip, date ?? DateTimeOffset.Now);
await _cachingLayer.SetAsync(cacheKey, solarTimes);
return Ok(solarTimes);
}
[HttpGet("by_location")]
public async Task<IActionResult> GetByLocation(double lat, double lon, DateTimeOffset? date)
{
/* ... */
}
},
/solartimes/by_ip SolarCalculator, , . CachingLayer, Redis, JSON-:
public class CachingLayer
{
private readonly IConnectionMultiplexer _redis;
public CachingLayer(IConnectionMultiplexer connectionMultiplexer) =>
_redis = connectionMultiplexer;
public async Task<T> TryGetAsync<T>(string key) where T : class
{
var result = await _redis.GetDatabase().StringGetAsync(key);
if (result.HasValue)
return JsonSerializer.Deserialize<T>(result.ToString());
return null;
}
public async Task SetAsync<T>(string key, T obj) where T : class =>
await _redis.GetDatabase().StringSetAsync(key, JsonSerializer.Serialize(obj));
}Startup, :
public class Startup
{
private readonly IConfiguration _configuration;
public Startup(IConfiguration configuration) =>
_configuration = configuration;
private string GetRedisConnectionString() =>
_configuration.GetConnectionString("Redis");
public void ConfigureServices(IServiceCollection services)
{
services.AddMvc(o => o.EnableEndpointRouting = false);
services.AddSingleton<IConnectionMultiplexer>(
ConnectionMultiplexer.Connect(GetRedisConnectionString()));
services.AddSingleton<CachingLayer>();
services.AddHttpClient<LocationProvider>();
services.AddTransient<SolarCalculator>();
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
app.UseDeveloperExceptionPage();
app.UseMvcWithDefaultRoute();
}
}, - , . , , , ( ), , .
, : - ( GeoIP), (Redis). , .
, -, , , , , . - , , middleware .
, . , . —
FakeApp, :
public class FakeApp : IDisposable
{
private readonly WebApplicationFactory<Startup> _appFactory;
public HttpClient Client { get; }
public FakeApp()
{
_appFactory = new WebApplicationFactory<Startup>();
Client = _appFactory.CreateClient();
}
public void Dispose()
{
Client.Dispose();
_appFactory.Dispose();
}
}WebApplicationFactory — , . API , .
HttpClient, . , .
Redis, , . , API (fixture) xUnit:
public class RedisFixture : IAsyncLifetime
{
private string _containerId;
public async Task InitializeAsync()
{
// Simplified, but ideally should bind to a random port
var result = await Cli.Wrap("docker")
.WithArguments("run -d -p 6379:6379 redis")
.ExecuteBufferedAsync();
_containerId = result.StandardOutput.Trim();
}
public async Task ResetAsync() =>
await Cli.Wrap("docker")
.WithArguments($"exec {_containerId} redis-cli FLUSHALL")
.ExecuteAsync();
public async Task DisposeAsync() =>
await Cli.Wrap("docker")
.WithArguments($"container kill {_containerId}")
.ExecuteAsync();
}IAsyncLifetime, , . Redis Docker .
,
RedisFixture ResetAsync, FLUSHALL, . Redis . , , .
, :
public class SolarTimeSpecs : IClassFixture<RedisFixture>, IAsyncLifetime
{
private readonly RedisFixture _redisFixture;
public SolarTimeSpecs(RedisFixture redisFixture)
{
_redisFixture = redisFixture;
}
// Reset Redis before each test
public async Task InitializeAsync() => await _redisFixture.ResetAsync();
[Fact]
public async Task User_can_get_solar_times_for_their_location_by_ip()
{
// Arrange
using var app = new FakeApp();
// Act
var response = await app.Client.GetStringAsync("/solartimes/by_ip");
var solarTimes = JsonSerializer.Deserialize<SolarTimes>(response);
// Assert
solarTimes.Sunset.Should().BeWithin(TimeSpan.FromDays(1)).After(solarTimes.Sunrise);
solarTimes.Sunrise.Should().BeCloseTo(DateTimeOffset.Now, TimeSpan.FromDays(1));
solarTimes.Sunset.Should().BeCloseTo(DateTimeOffset.Now, TimeSpan.FromDays(1));
}
}, .
FakeApp HttpClient , -.
/solartimes/by_ip, IP . GeoIP , , , .
, . , .
— GeoIP , , . , , , .
IP-, . , .
, middleware IP- :
public class FakeIpStartupFilter : IStartupFilter
{
public IPAddress Ip { get; set; } = IPAddress.Parse("::1");
public Action<IApplicationBuilder> Configure(Action<IApplicationBuilder> nextFilter)
{
return app =>
{
app.Use(async (ctx, next) =>
{
ctx.Connection.RemoteIpAddress = Ip;
await next();
});
nextFilter(app);
};
}
}FakeApp, :
public class FakeApp : IDisposable
{
private readonly WebApplicationFactory<Startup> _appFactory;
private readonly FakeIpStartupFilter _fakeIpStartupFilter = new FakeIpStartupFilter();
public HttpClient Client { get; }
public IPAddress ClientIp
{
get => _fakeIpStartupFilter.Ip;
set => _fakeIpStartupFilter.Ip = value;
}
public FakeApp()
{
_appFactory = new WebApplicationFactory<Startup>().WithWebHostBuilder(o =>
{
o.ConfigureServices(s =>
{
s.AddSingleton<IStartupFilter>(_fakeIpStartupFilter);
});
});
Client = _appFactory.CreateClient();
}
/* ... */
}, :
[Fact]
public async Task User_can_get_solar_times_for_their_location_by_ip()
{
// Arrange
using var app = new FakeApp
{
ClientIp = IPAddress.Parse("20.112.101.1")
};
var date = new DateTimeOffset(2020, 07, 03, 0, 0, 0, TimeSpan.FromHours(-5));
var expectedSunrise = new DateTimeOffset(2020, 07, 03, 05, 20, 37, TimeSpan.FromHours(-5));
var expectedSunset = new DateTimeOffset(2020, 07, 03, 20, 28, 54, TimeSpan.FromHours(-5));
// Act
var query = new QueryBuilder
{
{"date", date.ToString("O", CultureInfo.InvariantCulture)}
};
var response = await app.Client.GetStringAsync($"/solartimes/by_ip{query}");
var solarTimes = JsonSerializer.Deserialize<SolarTimes>(response);
// Assert
solarTimes.Sunrise.Should().BeCloseTo(expectedSunrise, TimeSpan.FromSeconds(1));
solarTimes.Sunset.Should().BeCloseTo(expectedSunset, TimeSpan.FromSeconds(1));
}- -, . , , , , , .
, , , , , . ( ) . .
, , , . , URL:
[Fact]
public async Task User_can_get_solar_times_for_a_specific_location_and_date()
{
// Arrange
using var app = new FakeApp();
var date = new DateTimeOffset(2020, 07, 03, 0, 0, 0, TimeSpan.FromHours(+3));
var expectedSunrise = new DateTimeOffset(2020, 07, 03, 04, 52, 23, TimeSpan.FromHours(+3));
var expectedSunset = new DateTimeOffset(2020, 07, 03, 21, 11, 45, TimeSpan.FromHours(+3));
// Act
var query = new QueryBuilder
{
{"lat", "50.45"},
{"lon", "30.52"},
{"date", date.ToString("O", CultureInfo.InvariantCulture)}
};
var response = await app.Client.GetStringAsync($"/solartimes/by_location{query}");
var solarTimes = JsonSerializer.Deserialize<SolarTimes>(response);
// Assert
solarTimes.Sunrise.Should().BeCloseTo(expectedSunrise, TimeSpan.FromSeconds(1));
solarTimes.Sunset.Should().BeCloseTo(expectedSunset, TimeSpan.FromSeconds(1));
}, , , , , . , , -, .
, , , . -.
, -
SolarCalculator LocationProvider, , , . , .
SolarCalculator :
public class SolarCalculator
{
private static TimeSpan CalculateSolarTimeOffset(Location location, DateTimeOffset instant,
double zenith, bool isSunrise)
{
/* ... */
}
public SolarTimes GetSolarTimes(Location location, DateTimeOffset date)
{
var sunriseOffset = CalculateSolarTimeOffset(location, date, 90.83, true);
var sunsetOffset = CalculateSolarTimeOffset(location, date, 90.83, false);
var sunrise = date.ResetTimeOfDay().Add(sunriseOffset);
var sunset = date.ResetTimeOfDay().Add(sunsetOffset);
return new SolarTimes
{
Sunrise = sunrise,
Sunset = sunset
};
}
},
LocationProvider , GetSolarTimes . , .
, :
[ApiController]
[Route("solartimes")]
public class SolarTimeController : ControllerBase
{
private readonly SolarCalculator _solarCalculator;
private readonly LocationProvider _locationProvider;
private readonly CachingLayer _cachingLayer;
public SolarTimeController(
SolarCalculator solarCalculator,
LocationProvider locationProvider,
CachingLayer cachingLayer)
{
_solarCalculator = solarCalculator;
_locationProvider = locationProvider;
_cachingLayer = cachingLayer;
}
[HttpGet("by_ip")]
public async Task<IActionResult> GetByIp(DateTimeOffset? date)
{
var ip = HttpContext.Connection.RemoteIpAddress;
var cacheKey = ip.ToString();
var cachedSolarTimes = await _cachingLayer.TryGetAsync<SolarTimes>(cacheKey);
if (cachedSolarTimes != null)
return Ok(cachedSolarTimes);
// Composition instead of dependency injection
var location = await _locationProvider.GetLocationAsync(ip);
var solarTimes = _solarCalculator.GetSolarTimes(location, date ?? DateTimeOffset.Now);
await _cachingLayer.SetAsync(cacheKey, solarTimes);
return Ok(solarTimes);
}
/* ... */
}, . , - :
[Fact]
public void User_can_get_solar_times_for_New_York_in_November()
{
// Arrange
var location = new Location
{
Latitude = 40.71,
Longitude = -74.00
};
var date = new DateTimeOffset(2019, 11, 04, 00, 00, 00, TimeSpan.FromHours(-5));
var expectedSunrise = new DateTimeOffset(2019, 11, 04, 06, 29, 34, TimeSpan.FromHours(-5));
var expectedSunset = new DateTimeOffset(2019, 11, 04, 16, 49, 04, TimeSpan.FromHours(-5));
// Act
var solarTimes = new SolarCalculator().GetSolarTimes(location, date);
// Assert
solarTimes.Sunrise.Should().BeCloseTo(expectedSunrise, TimeSpan.FromSeconds(1));
solarTimes.Sunset.Should().BeCloseTo(expectedSunset, TimeSpan.FromSeconds(1));
}
[Fact]
public void User_can_get_solar_times_for_Tromso_in_January()
{
// Arrange
var location = new Location
{
Latitude = 69.65,
Longitude = 18.96
};
var date = new DateTimeOffset(2020, 01, 03, 00, 00, 00, TimeSpan.FromHours(+1));
var expectedSunrise = new DateTimeOffset(2020, 01, 03, 11, 48, 31, TimeSpan.FromHours(+1));
var expectedSunset = new DateTimeOffset(2020, 01, 03, 11, 48, 45, TimeSpan.FromHours(+1));
// Act
var solarTimes = new SolarCalculator().GetSolarTimes(location, date);
// Assert
solarTimes.Sunrise.Should().BeCloseTo(expectedSunrise, TimeSpan.FromSeconds(1));
solarTimes.Sunset.Should().BeCloseTo(expectedSunset, TimeSpan.FromSeconds(1));
}, . , , , .
, , , , , .
, -, Redis. , , , .
, , , . , , , .
Redis, , , :
[Fact]
public async Task User_can_get_solar_times_for_their_location_by_ip_multiple_times()
{
// Arrange
using var app = new FakeApp();
// Act
var collectedSolarTimes = new List<SolarTimes>();
for (var i = 0; i < 3; i++)
{
var response = await app.Client.GetStringAsync("/solartimes/by_ip");
var solarTimes = JsonSerializer.Deserialize<SolarTimes>(response);
collectedSolarTimes.Add(solarTimes);
}
// Assert
collectedSolarTimes.Select(t => t.Sunrise).Distinct().Should().ContainSingle();
collectedSolarTimes.Select(t => t.Sunset).Distinct().Should().ContainSingle();
}, . , .
, :
, — 55 , — (- ). , , , , , .
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- — , . , best practices , .
, -. — , , . .
, , ; , . , , .
:
- best practices
- , ,
- ,
. , :
- Write tests. Not too many. Mostly integration (Kent C. Dodds)
- Mocking is a Code Smell (Eric Elliott)
- Test-induced design damage (David Heinemeier Hansson)
- Slow database test fallacy (David Heinemeier Hansson)
- Fallacy of Unit Testing (Aaron W. Hsu)
- The No. 1 unit testing best practice: Stop doing it (Vitaliy Pisarev)
- Testing of Microservices at Spotify (André Schaffer)