Add API client in preparation for new microservices.

Website.Tests/Data/ApiClientTests.cs

@@ -0,0 +1,83 @@
+using System;
+using System.Net.Http;
+using System.Threading.Tasks;
+using FluentAssertions;
+using RichardSzalay.MockHttp;
+using Website.Data;
+using Xunit;
+
+namespace Website.Tests.Data {
+	public class ApiClientTests {
+		private class TestApiClient : ApiClient {
+			public TestApiClient(HttpClient client) : base(client) {
+			}
+
+			public async Task<T> Post<T>(string url, object value, object query = null) => await base.Post<T>(url, value, query);
+
+			public async Task<T> Get<T>(string url, object query = null) => await base.Get<T>(url, query);
+		}
+
+		private class TestObject {
+			public int TestProperty { get; set; }
+		}
+
+		private static HttpClient MakeHttpClient(HttpMethod method, string url, string response) {
+			var httpMessageHandler = new MockHttpMessageHandler();
+			httpMessageHandler.When(method, url).Respond("application/json", response);
+
+			var httpClient = httpMessageHandler.ToHttpClient();
+			httpClient.BaseAddress = new Uri("http://example.com");
+			return httpClient;
+		}
+
+		[Fact]
+		public async Task Get_WithUrl_ReturnsResult() {
+			var httpClient = MakeHttpClient(HttpMethod.Get, "/test", @"{""TestProperty"":1}");
+
+			var expected = new TestObject {TestProperty = 1};
+
+			var client = new TestApiClient(httpClient);
+			(await client.Get<TestObject>("/test")).Should().BeEquivalentTo(expected);
+		}
+
+		[Fact]
+		public async Task Get_WithUrlAndQuery_ReturnsResult() {
+			var httpClient = MakeHttpClient(HttpMethod.Get, "/test?query1=1&query2=2", @"{""TestProperty"":1}");
+
+			var expected = new TestObject {TestProperty = 1};
+
+			var client = new TestApiClient(httpClient);
+			(await client.Get<TestObject>("/test", new {query1 = 1, query2 = 2})).Should().BeEquivalentTo(expected);
+		}
+
+		[Fact]
+		public void Get_WithUrlThatReturns404_ThrowsException() {
+			var httpClient = MakeHttpClient(HttpMethod.Get, "/test", "");
+
+			var client = new TestApiClient(httpClient);
+
+			client.Invoking(apiClient => apiClient.Get<TestObject>("/404")).Should().Throw<ApiCallException>()
+			      .WithMessage("Error calling API http://example.com/404: 404, No matching mock handler for \"GET http://example.com/404\"");
+		}
+
+		[Fact]
+		public async Task Post_WithUrlAndValue_ReturnsResult() {
+			var httpClient = MakeHttpClient(HttpMethod.Post, "/test", @"{""TestProperty"":1}");
+
+			var expected = new TestObject {TestProperty = 1};
+
+			var client = new TestApiClient(httpClient);
+			(await client.Post<TestObject>("/test", "value")).Should().BeEquivalentTo(expected);
+		}
+
+		[Fact]
+		public async Task Post_WithUrlAndValueAndQuery_ReturnsResult() {
+			var httpClient = MakeHttpClient(HttpMethod.Post, "/test?query1=1&query2=2", @"{""TestProperty"":1}");
+
+			var expected = new TestObject {TestProperty = 1};
+
+			var client = new TestApiClient(httpClient);
+			(await client.Post<TestObject>("/test", "value", new {query1 = 1, query2 = 2})).Should().BeEquivalentTo(expected);
+		}
+	}
+}

Website.Tests/Website.Tests.csproj

@@ -16,6 +16,7 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.4.0" />
     <PackageReference Include="mysqlconnector" Version="0.61.0" />
     <PackageReference Include="nsubstitute" Version="4.2.1" />
+    <PackageReference Include="RichardSzalay.MockHttp" Version="6.0.0" />
     <PackageReference Include="xunit" Version="2.4.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.1">
       <PrivateAssets>all</PrivateAssets>

Website/Data/ApiCallException.cs

@@ -0,0 +1,12 @@
+using System;
+using System.Net.Http;
+
+namespace Website.Data {
+	public class ApiCallException : Exception {
+		private readonly HttpResponseMessage Response;
+
+		public ApiCallException(HttpResponseMessage response):base($"Error calling API {response.RequestMessage.RequestUri}: {(int)response.StatusCode}, {response.ReasonPhrase}") {
+			Response = response;
+		}
+	}
+}

Website/Data/ApiClient.cs

@@ -0,0 +1,48 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Net.Http;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.WebUtilities;
+using Newtonsoft.Json;
+
+namespace Website.Data {
+	public abstract class ApiClient {
+		private readonly HttpClient _client;
+
+		protected ApiClient(HttpClient client) {
+			_client = client;
+		}
+
+		private IDictionary<string, string> ParseQueryParameters(object query) {
+			var type = query.GetType();
+			var props = type.GetProperties();
+			return props.ToDictionary(info => info.Name, info => info.GetValue(query, null).ToString());
+		}
+
+		private async Task<T> Send<T>(HttpMethod method, string url, object query, HttpContent content = null) {
+			if (query != null)
+				url = QueryHelpers.AddQueryString(url, ParseQueryParameters(query));
+
+			using var httpRequest = new HttpRequestMessage(method, url) { Content = content };
+			var response = await _client.SendAsync(httpRequest);
+
+			if (!response.IsSuccessStatusCode)
+				throw new ApiCallException(response);
+
+			var json = await response.Content.ReadAsStringAsync();
+			return JsonConvert.DeserializeObject<T>(json);
+		}
+
+		protected async Task<T> Post<T>(string url, object value, object query = null) {
+			var json = JsonConvert.SerializeObject(value);
+			using var requestBody = new StringContent(json, Encoding.UTF8, "application/json");
+			return await Send<T>(HttpMethod.Post, url, query, requestBody);
+		}
+
+		protected async Task<T> Get<T>(string url, object query = null) {
+			return await Send<T>(HttpMethod.Get, url, query);
+		}
+
+	}
+}