Add backend test harness with mock SQLite

GameList.Tests/Support/TestClientExtensions.cs

@@ -0,0 +1,46 @@
+using System.Net.Http.Json;
+using System.Text.Json;
+
+namespace GameList.Tests.Support;
+
+internal static class TestClientExtensions
+{
+    public static Task<HttpResponseMessage> RegisterAsync(this HttpClient client, string username, bool admin = false)
+    {
+        return client.PostAsJsonAsync("/api/auth/register", new
+        {
+            Username = username,
+            Password = "Pass123!",
+            DisplayName = $"{username}-name",
+            AdminKey = admin ? "admin-key" : null
+        });
+    }
+
+    public static Task<HttpResponseMessage> LoginAsync(this HttpClient client, string username, string password)
+    {
+        return client.PostAsJsonAsync("/api/auth/login", new
+        {
+            Username = username,
+            Password = password
+        });
+    }
+
+    public static async Task<int> CreateSuggestionAsync(this HttpClient client, string name)
+    {
+        var response = await client.PostAsJsonAsync("/api/suggestions", new
+        {
+            Name = name,
+            Genre = "Coop",
+            Description = (string?)null,
+            ScreenshotUrl = (string?)null,
+            YoutubeUrl = (string?)null,
+            GameUrl = (string?)null,
+            MinPlayers = (int?)null,
+            MaxPlayers = (int?)null
+        });
+
+        response.EnsureSuccessStatusCode();
+        var json = await response.Content.ReadFromJsonAsync<JsonElement>();
+        return json.GetProperty("Id").GetInt32();
+    }
+}