Chronos.Net

Simple library to help abstracting time in dotnet projects, usually for testing purpose.

Chronos.Abstractions

Contains:

• An IDateTimeProvider interface which exposes Now or UtcNow properties.
• An IDateTimeOffsetProvider interface which exposes Now or UtcNow properties.

Chronos.Net

Contains:

• A simple implementation DateTimeProvider of the IDateTimeProvider interface.
• A simple implementation DateTimeOffsetProvider of the IDateTimeOffsetProvider interface.
• And 2 IServiceCollection extensions method to provide default implementations:
  • AddDateTimeProvider() to provide a singleton of DateTimeProvider when an IDateTimeProvider is required
  • AddDateTimeOffsetProvider() to provide a singleton of DateTimeOffsetProvider when an IDateTimeOffsetProvider is required

public void ConfigureServices(IServiceCollection services)
{
    ...
    services.AddDateTimeProvider();
    services.AddDateTimeOffsetProvider();
    ...
}

Chronos.AspNetCore [Deprecated]

Chronos.AspNetCore was kept for compatibility reasons, but should be removed in further releases. Please use the IServiceCollection extensions from Chronos.Net instead which requires less dependencies.

Contains:

• And 2 WebHostBuilder extensions method to provide default implementations:
  • UseDateTimeProvider() to provide a singleton of DateTimeProvider when an IDateTimeProvider is required
  • UseDateTimeOffsetProvider() to provide a singleton of DateTimeOffsetProvider when an IDateTimeOffsetProvider is required

public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
    WebHost.CreateDefaultBuilder(args)
    .UseDateTimeProvider()
    .UseDateTimeOffsetProvider()
    .UseStartup<Startup>();

Usage

Then instead of using DateTime.Now, DateTime.UtcNow, DateTimeOffset.Now or DateTimeOffset.UtcNow, you should use IDateTimeProvider.Now, IDateTimeProvider.UtcNow, IDateTimeOffsetProvider.Now or IDateTimeOffsetProvider.UtcNow which would enable you to fake/mock the time in your tests.
Example with FakeItEasy:

var dateTimeProvider = A.Fake<IDateTimeProvider>();
A.CallTo(() => dateTimeProvider.Now).Returns(new DateTime(2019, 3, 6, 9, 0, 0));

var franceOffset = TimeZoneInfo.FindSystemTimeZoneById("Romance Standard Time").BaseUtcOffset;
var dateTimeOffsetProvider = A.Fake<IDateTimeOffsetProvider>();
A.CallTo(() => dateTimeOffsetProvider.Now).Returns(new DateTime(2019, 3, 6, 9, 0, 0, franceOffset));

A sample web project can be found in the samples folder