Shows how to unit test a Jokes class that calls the JokeAPI through HttpClient with NUnit, by implementing a custom HttpMessageHandler to intercept requests instead of hitting the real https://v2.jokeapi.dev/joke/Programming endpoint, avoiding flaky integration-test failures when the API is down. ...
Thomas Ardal
Meet Thomas, the founder and developer behind elmah.io. Thomas blogs about everything technical from C# and ASP.NET Core to machine learning.
Mocking HttpClient requests for C# unit tests
"Secret" elmah.io features #2 - Correlate messages from apps
Explains setting up correlation IDs across ASP.NET Core services with the Elmah.Io.AspNetCore and Elmah.Io.Extensions.Logging packages, configured via AddElmahIo and UseElmahIo in Program.cs, so a request, its NullReferenceException, and related ILogger messages group into one elmah.io view. ...
Testing logging code with Microsoft.Extensions.Logging and FakeLogger
Shows how to unit test logging calls in a Math.Divide method using the FakeLogger<T> class from the Microsoft.Extensions.Diagnostics.Testing NuGet package, asserting on logger.Collector.LatestRecord.Message and Collector.Count with NUnit rather than only relying on NullLogger. ...
"Secret" elmah.io features #1 - Include source code in errors
Explains how to install the Elmah.Io.Client.Extensions.SourceCode NuGet package, set EmbedAllSources true in the .csproj, and call msg.WithSourceCodeFromPdb() inside the AddElmahIo OnMessage callback so elmah.io shows the exact source line from a stack trace without cloning the repo. ...
Validate NuGet packages before publishing from GitHub Actions
Uses a joke NuGet package called RickrollingMiddleware to show how dotnet-validate (installed via dotnet tool install) catches failing Source Link, Deterministic, and Compiler Flags checks in GitHub Actions, then fixes them by adding DebugType embedded and PublishRepositoryUrl to the .csproj. ...
Dependency Injection using keyed services is finally in ASP.NET
Demonstrates ASP.NET Core 8's AddKeyedSingleton and FromKeyedServices attribute by injecting two named ServiceBusSender clients, taskTopic and preprocessorTopic, from Azure.Messaging.ServiceBus into a controller, replacing a hand-written Topics wrapper class used to work around the ambiguity. ...
Validate JSON files against schema in Azure DevOps build
Provides copy-paste PowerShell code using the Test-Json cmdlet against a schema.json file to validate JSON syntax and structure in an Azure DevOps build, covering both the classic-editor PowerShell Script task and a YAML PowerShell@2 pipeline step, plus the pwsh: true fix needed on windows-latest. ...
Setting up better logging in Azure Functions
Shows how to replace host.json's Application-Insights-only logging in in-process Azure Functions by installing Microsoft.Azure.Functions.Extensions, adding a FunctionsStartup-based Startup.cs, and calling AddLogging with Microsoft.Extensions.Logging.Console for full ILoggingBuilder control. ...
Conditionally add middleware in ASP.NET Core
Extends a TimingMiddleware class that sets an X-Took response header, comparing an in-class StartsWithSegments("/api") if-check, which still runs the middleware for every request, against wrapping app.UseWhen in Program.cs so the pipeline branch only executes for matching paths. ...