feat(os): migrate from Windows to Ubuntu linux and add tests

src/Timezone.Core/Extensions/MappingExtensions.cs

@@ -19,6 +19,11 @@ public static class MappingExtensions
         BaseOffset = timezone.BaseUtcOffset
     };
 
+    public static TimeZoneConversionResultResponse ToResponse(this TimeZoneConversionResultDomain domain) => new()
+    {
+        DateTime = domain.DateTime
+    };
+
     public static IEnumerable<TimezoneResponse> ToResponse(this IEnumerable<TimeZoneInfo> timezones) =>
         timezones.Select(x => x.ToResponse());
 }

src/Timezone.Core/Models/TimeZoneConversionResultDomain.cs

@@ -0,0 +1,6 @@
+namespace Timezone.Core.Models;
+
+public class TimeZoneConversionResultDomain
+{
+    public DateTime DateTime { get; set; }
+}

src/Timezone.Core/Models/TimeZoneConversionResultResponse.cs

@@ -0,0 +1,6 @@
+namespace Timezone.Core.Models;
+
+public class TimeZoneConversionResultResponse
+{
+    public DateTime DateTime { get; set; }
+}

src/Timezone.Core/Services/ITimezoneService.cs

@@ -4,7 +4,7 @@ namespace Timezone.Core.Services;
 
 public interface ITimezoneService
 {
-    DateTime ConvertFromOneTimezoneToAnother(TimeZoneConversionDomain request);
+    TimeZoneConversionResultDomain ConvertFromOneTimezoneToAnother(TimeZoneConversionDomain request);
     IEnumerable<TimeZoneInfo> GetTimezones();
     TimeZoneInfo? GetTimezone(string timezoneId);
 }

src/Timezone.Core/Services/TimezoneService.cs

@@ -6,20 +6,18 @@ public class TimezoneService : ITimezoneService
 {
     public IEnumerable<TimeZoneInfo> GetTimezones() => TimeZoneInfo.GetSystemTimeZones();
 
-    public TimeZoneInfo? GetTimezone(string timezoneId)
-    {
-        return TimezoneHelper.GetTimezone(timezoneId);
-    }
+    public TimeZoneInfo? GetTimezone(string timezoneId) => TimezoneHelper.GetTimezone(timezoneId);
 
-    public DateTime ConvertFromOneTimezoneToAnother(TimeZoneConversionDomain request)
+    public TimeZoneConversionResultDomain ConvertFromOneTimezoneToAnother(TimeZoneConversionDomain request)
     {
         ValidateRequest(request);
 
-        var dateTime = DateTime.SpecifyKind(request.DateTime, DateTimeKind.Unspecified);
-        var dateTimeUtc = dateTime.ConvertToUtc(request.FromTimezone);
-        var dateTimeConverted = TimeZoneInfo.ConvertTimeFromUtc(dateTimeUtc, request.ToTimezone);
+        var conversionResult = TimeZoneInfo.ConvertTimeBySystemTimeZoneId(
+            SanitizeDateTime(request.DateTime),
+            request.FromTimezone.Id,
+            request.ToTimezone.Id);
 
-        return dateTimeConverted;
+        return new TimeZoneConversionResultDomain { DateTime = SanitizeDateTime(conversionResult) };
     }
 
     private static void ValidateRequest(TimeZoneConversionDomain request)
@@ -39,4 +37,12 @@ private static void ValidateRequest(TimeZoneConversionDomain request)
             throw new ArgumentException("ToTimezone provided is invalid. Please provide a valid timezone.");
         }
     }
+
+    /// <summary>
+    /// This sanitizes the DateTime object by removing the DateTimeKind.
+    /// This is necessary because the TimeZoneInfo.ConvertTimeBySystemTimeZoneId method
+    /// does not work correctly with DateTimeKind.Local or DateTimeKind.Utc.
+    /// Additionally, this method removes "Z" from the end of the DateTime string.
+    /// </summary>
+    private static DateTime SanitizeDateTime(DateTime dateTime) => DateTime.SpecifyKind(dateTime, DateTimeKind.Unspecified);
 }

src/Timezone.Core/Timezone.Core.csproj

@@ -9,14 +9,9 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <Compile Remove="Handler\**"/>
-    <EmbeddedResource Remove="Handler\**"/>
-    <None Remove="Handler\**"/>
-  </ItemGroup>
-
-  <ItemGroup>
-    <PackageReference Include="Microsoft.Extensions.Http" Version="8.0.1" />
-    <PackageReference Include="System.Linq.Async" Version="6.0.1"/>
+    <Compile Remove="Handler\**" />
+    <EmbeddedResource Remove="Handler\**" />
+    <None Remove="Handler\**" />
   </ItemGroup>
 
 </Project>

src/Timezone.WebApi/Controllers/ConvertController.cs

@@ -12,15 +12,15 @@ namespace TimezoneWebApi.Controllers;
 public class ConvertController(ITimezoneService timezoneService) : Controller
 {
     [HttpPost]
-    [ProducesResponseType(StatusCodes.Status200OK, Type= typeof(DateTime))]
+    [ProducesResponseType(StatusCodes.Status200OK, Type = typeof(DateTime))]
     [ProducesResponseType(StatusCodes.Status400BadRequest, Type = typeof(ErrorModel))]
     [SwaggerRequestExample(typeof(TimeZoneConversionRequest), typeof(PostConvertExamples))]
-    public async Task<DateTime> ConvertTime(TimeZoneConversionRequest request)
+    public async Task<TimeZoneConversionResultResponse> ConvertTime(TimeZoneConversionRequest request)
     {
         var domain = request.ToDomain();
 
-        var response = timezoneService.ConvertFromOneTimezoneToAnother(domain);
+        var conversionResult = timezoneService.ConvertFromOneTimezoneToAnother(domain);
 
-        return response;
+        return conversionResult.ToResponse();
     }
 }

src/Timezone.WebApi/Controllers/Examples/PostConvertExamples.cs

@@ -11,7 +11,7 @@ public IEnumerable<SwaggerExample<TimeZoneConversionRequest>> GetExamples()
             "Example 1 - Convert UTC to New York Time",
             new TimeZoneConversionRequest
             {
-                DateTime = DateTime.UtcNow,
+                DateTime = TimeProvider.System.GetUtcNow().DateTime,
                 FromTimezone = "UTC",
                 ToTimezone = "America/New_York"
             });
@@ -21,7 +21,7 @@ public IEnumerable<SwaggerExample<TimeZoneConversionRequest>> GetExamples()
             "Example 2 - Convert New York Time to UTC",
             new TimeZoneConversionRequest
             {
-                DateTime = TimeZoneInfo.ConvertTime(DateTime.UtcNow, TimeZoneInfo.FindSystemTimeZoneById("America/New_York")),
+                DateTime = TimeZoneInfo.ConvertTime(TimeProvider.System.GetUtcNow().DateTime, TimeZoneInfo.FindSystemTimeZoneById("America/New_York")),
                 FromTimezone = "America/New_York",
                 ToTimezone = "UTC"
             });
@@ -31,7 +31,7 @@ public IEnumerable<SwaggerExample<TimeZoneConversionRequest>> GetExamples()
             "Example 3 - Convert from one timezone to another timezone",
             new TimeZoneConversionRequest
             {
-                DateTime = TimeZoneInfo.ConvertTime(DateTime.UtcNow, TimeZoneInfo.FindSystemTimeZoneById("America/New_York")),
+                DateTime = TimeZoneInfo.ConvertTime(TimeProvider.System.GetUtcNow().DateTime, TimeZoneInfo.FindSystemTimeZoneById("America/New_York")),
                 FromTimezone = "America/New_York",
                 ToTimezone = "Europe/London"
             });

src/Timezone.WebApi/Dockerfile

@@ -1,15 +1,15 @@
 # Using Ubuntu Linux, because it is a full version of Linux
 # I would stay away from smaller versions of Linux, like Alpine, as we retrieve timezones from Operating System
+FROM mcr.microsoft.com/dotnet/aspnet:8.0-noble AS base
 
+# The rest of Dockerfile has been generated by Visual Studio
 # See https://aka.ms/customizecontainer to learn how to customize your debug container and how Visual Studio uses this Dockerfile to build your images for faster debugging.
+
 # This stage is used when running from VS in fast mode (Default for Debug configuration)
-FROM mcr.microsoft.com/dotnet/aspnet:8.0-noble AS base
 USER app
 WORKDIR /app
-EXPOSE 8080
 EXPOSE 8081
 
-
 # This stage is used to build the service project
 FROM mcr.microsoft.com/dotnet/sdk:8.0-noble AS build
 ARG BUILD_CONFIGURATION=Release

src/Timezone.WebApi/Program.cs

@@ -1,5 +1,11 @@
+using System.Runtime.InteropServices;
 using TimezoneWebApi.Dependency;
 
+if (!RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
+{
+    throw new PlatformNotSupportedException("Currently, this application is designed to work exclusively on Linux/Docker due to its specific timezone support. Support for other operating systems is not yet provided.");
+}
+
 var builder = WebApplication.CreateBuilder(args);
 
 var app = builder

src/Timezone.WebApi/Properties/launchSettings.json

@@ -1,14 +1,5 @@
 {
   "profiles": {
-    "https": {
-      "commandName": "Project",
-      "launchBrowser": true,
-      "environmentVariables": {
-        "ASPNETCORE_ENVIRONMENT": "Development"
-      },
-      "dotnetRunMessages": true,
-      "applicationUrl": "https://localhost:5280"
-    },
     "Docker": {
       "commandName": "Docker",
       "launchBrowser": true,

src/Timezone.WebApi/TimezoneWebApi.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk.Web">
+<Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
     <TargetFramework>net8.0</TargetFramework>
@@ -12,18 +12,14 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="8.0.10" />
-    <PackageReference Include="Microsoft.Extensions.Caching.StackExchangeRedis" Version="8.0.10" />
-    <PackageReference Include="Microsoft.Extensions.Http.Polly" Version="8.0.10" />
+    <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="8.0.11" />
     <PackageReference Include="Microsoft.VisualStudio.Azure.Containers.Tools.Targets" Version="1.21.0" />
-    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.8.1" />
+    <PackageReference Include="Swashbuckle.AspNetCore" Version="7.2.0" />
     <PackageReference Include="Swashbuckle.AspNetCore.Filters" Version="8.0.2" />
-    <PackageReference Include="OpenTelemetry.Exporter.Console" Version="1.9.0" />
-    <PackageReference Include="OpenTelemetry.Extensions.Hosting" Version="1.9.0" />
-    <PackageReference Include="OpenTelemetry.Instrumentation.AspNetCore" Version="1.9.0" />
-    <PackageReference Include="OpenTelemetry.Instrumentation.Http" Version="1.9.0" />
-    <PackageReference Include="System.Linq.Async" Version="6.0.1" />
-    <PackageReference Include="System.Linq.Async.Queryable" Version="6.0.1" />
+    <PackageReference Include="OpenTelemetry.Exporter.Console" Version="1.10.0" />
+    <PackageReference Include="OpenTelemetry.Extensions.Hosting" Version="1.10.0" />
+    <PackageReference Include="OpenTelemetry.Instrumentation.AspNetCore" Version="1.10.1" />
+    <PackageReference Include="OpenTelemetry.Instrumentation.Http" Version="1.10.0" />
   </ItemGroup>
 
   <ItemGroup>

tests/Timezone.FunctionalTests/Features/ConvertController.feature

@@ -0,0 +1,18 @@
+Feature: Timezone Conversion
+As an API user,
+I want to ensure that the timezone conversion API is accurate
+So that I can reliably convert date and time across different timezones
+
+    Scenario Outline: Requesting to convert time from one timezone to another timezone should return the correct time
+        Given I have a request to convert date '<DateTime>' from '<FromTimezone>' to '<ToTimezone>'
+        When I send the request
+        Then the response should return '200' status code
+        And the response should correctly convert the time into '<ExpectedDateTime>'
+
+        Examples:
+          | DateTime               | FromTimezone       | ToTimezone         | ExpectedDateTime       |
+          | "2023-02-01T12:00:00" | "UTC"              | "America/New_York" | "2023-02-01T07:00:00" |
+          | "2023-02-01T07:00:00" | "America/New_York" | "UTC"              | "2023-02-01T12:00:00" |
+          | "2023-02-01T07:00:00" | "America/New_York" | "Europe/London"    | "2023-02-01T12:00:00" |
+          | "2023-02-01T07:00:00" | "America/New_York" | "Asia/Tokyo"       | "2023-02-01T21:00:00" |
+

tests/Timezone.FunctionalTests/Features/TimezoneController.feature

@@ -0,0 +1,24 @@
+Feature: Timezone Retrieval
+As an API user,
+I want to be able to interact with the timezone data,
+So that I can retrieve all timezones, request specific timezone information, and receive proper error handling for invalid timezone requests.
+
+    Scenario: Requesting all timezones should return all timezones
+        Given I have a request to get all timezones
+        When I send the request
+        Then the response should return '200' status code
+        # As of 15th of December 2024, there are 419 timezones.
+        Then I should get at least 400 timezones
+
+    Scenario: Request one valid timezone should return one timezone
+        Given I have a request to get 'America/New_York' timezone
+        When I send the request
+        Then the response should return '200' status code
+        Then the response should contain timezone information:
+        | Name                         | Offset |
+        | (UTC-05:00) America/New_York | -5     |
+
+    Scenario: Request one invalid timezone should return 404
+        Given I have a request to get 'invalid-timezone' timezone
+        When I send the request
+        Then the response should return '404' status code

tests/Timezone.FunctionalTests/StepDefinitions/ConvertStepDefinitions.cs

@@ -0,0 +1,47 @@
+namespace Timezone.FunctionalTests.StepDefinitions;
+
+using System.Globalization;
+using System.Text.Json;
+using Core.Models;
+using FluentAssertions;
+using RestSharp;
+using Support;
+
+[Binding]
+public class ConvertStepDefinitions(ScenarioContext context) : TestBase(context)
+{
+    private static JsonSerializerOptions JsonSerializerOptions => new()
+    {
+        PropertyNameCaseInsensitive = true,
+    };
+
+    [Given(@"I have a request to convert date '""([^""]*)""' from '""([^""]*)""' to '""([^""]*)""'")]
+    public void GivenIHaveARequestToConvertDateFromTo(string dateTimeString, string fromTimezone, string toTimezone)
+    {
+        var request = new RestRequest("/convert", Method.Post) { RequestFormat = DataFormat.Json };
+
+        request.AddBody(new TimeZoneConversionRequest
+        {
+            DateTime = DateTime.Parse(dateTimeString, CultureInfo.InvariantCulture),
+            FromTimezone = fromTimezone,
+            ToTimezone = toTimezone
+        });
+
+        // Add to context
+        Context.Set(request);
+    }
+
+    [Then(@"the response should correctly convert the time into '""([^""]*)""'")]
+    public void ThenTheResponseShouldCorrectlyConvertTheTimeInto(string dateTime)
+    {
+        // Arrange
+        var expected = DateTime.Parse(dateTime, CultureInfo.InvariantCulture);
+
+        // Act
+        var rawResponse = Context.Get<RestResponse>();
+        var response = JsonSerializer.Deserialize<TimeZoneConversionResultResponse>
+            (rawResponse.Content, JsonSerializerOptions);
+
+        response.DateTime.Should().Be(expected);
+    }
+}