add tests

test/TrueLayer.Tests/Auth/AuthApiCacheDecoratorTests.cs

@@ -0,0 +1,81 @@
+using System;
+using System.Net;
+using System.Threading.Tasks;
+using FluentAssertions;
+using TrueLayer.Auth;
+using TrueLayer.Models;
+using TrueLayer.Tests.Mocks;
+using Xunit;
+
+namespace TrueLayer.Tests.Auth;
+
+public class AuthApiCacheDecoratorTests
+{
+    private readonly InMemoryAuthTokenCacheMock _authTokenCache = new();
+    private readonly AuthApiMock _authApiMock = new();
+    private readonly AuthApiCacheDecorator _authClient;
+
+    public AuthApiCacheDecoratorTests()
+    {
+        _authClient = new AuthApiCacheDecorator(_authApiMock ,_authTokenCache);
+    }
+
+    [Fact]
+    public async Task GetAuthToken_ResponseInCache_ReturnsCachedAuthToken()
+    {
+        const string scope = AuthorizationScope.Payments;
+
+        var expectedResponse = new GetAuthTokenResponse("token", 3600, "Bearer", scope);
+        var request = new GetAuthTokenRequest(scope);
+        _authApiMock.SetGetAuthToken(new ApiResponse<GetAuthTokenResponse>(expectedResponse, HttpStatusCode.OK, "trace"));
+        await _authClient.GetAuthToken(request);
+        _authApiMock.ResetGetAuthToken();
+
+        //Act
+        var response = await _authClient.GetAuthToken(request);
+
+        //Assert
+        response.StatusCode.Should().Be(HttpStatusCode.OK);
+        response.Data.Should().BeEquivalentTo(expectedResponse);
+    }
+
+    [Fact]
+    public async Task GetAuthToken_SuccessfulResponse_SetCache()
+    {
+        const string scope = AuthorizationScope.Payments;
+
+        var expectedResponse = new GetAuthTokenResponse("token123", 3600, "Bearer", scope);
+        _authApiMock.SetGetAuthToken(new ApiResponse<GetAuthTokenResponse>(expectedResponse, HttpStatusCode.OK, "trace"));
+
+        var request = new GetAuthTokenRequest(scope);
+
+        //Act
+        var response = await _authClient.GetAuthToken(request);
+
+        //Assert
+        response.StatusCode.Should().Be(HttpStatusCode.OK);
+        response.Data.Should().BeEquivalentTo(expectedResponse);
+        _authTokenCache.TryGetValue($"tl-auth-token-{scope}", out var cachedResponse);
+        cachedResponse!.StatusCode.Should().Be(HttpStatusCode.OK);
+        cachedResponse.Data.Should().BeEquivalentTo(expectedResponse);
+    }
+
+    [Fact]
+    public async Task GetAuthToken_UnsuccessfulResponse_CacheIsNotSet()
+    {
+        const string scope = AuthorizationScope.Payments;
+
+        var expectedResponse = new ProblemDetails("Type", "Title", null, null, null);
+        _authApiMock.SetGetAuthToken(new ApiResponse<GetAuthTokenResponse>(expectedResponse, HttpStatusCode.BadRequest, "trace"));
+
+        var request = new GetAuthTokenRequest(scope);
+
+        //Act
+        var response = await _authClient.GetAuthToken(request);
+
+        //Assert
+        response.StatusCode.Should().Be(HttpStatusCode.BadRequest);
+        response.Problem.Should().BeEquivalentTo(expectedResponse);
+        _authTokenCache.IsEmpty.Should().BeTrue();
+    }
+}

test/TrueLayer.Tests/Mocks/AuthApiMock.cs

@@ -13,6 +13,11 @@ public void SetGetAuthToken(ApiResponse<GetAuthTokenResponse> response)
         _response = response;
     }
 
+    public void ResetGetAuthToken()
+    {
+        _response = null;
+    }
+
     public ValueTask<ApiResponse<GetAuthTokenResponse>> GetAuthToken(GetAuthTokenRequest authTokenRequest, CancellationToken cancellationToken = default)
     {
         return new ValueTask<ApiResponse<GetAuthTokenResponse>>(_response!);

test/TrueLayer.Tests/Mocks/InMemoryAuthTokenCacheMock.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Collections.Generic;
+using TrueLayer.Auth;
+
+namespace TrueLayer.Tests.Mocks;
+
+public class InMemoryAuthTokenCacheMock : IAuthTokenCache
+{
+    private readonly Dictionary<string, ApiResponse<GetAuthTokenResponse>?> _dictionary = new();
+
+    public bool TryGetValue(string key, out ApiResponse<GetAuthTokenResponse>? value)
+    {
+       return _dictionary.TryGetValue(key, out value);
+    }
+
+    public void Set(string key, ApiResponse<GetAuthTokenResponse> value, TimeSpan absoluteExpirationRelativeToNow)
+    {
+        _dictionary.Add(key, value);
+    }
+
+    public bool IsEmpty => _dictionary.Count == 0;
+}
+
+