Stravaig Logging Diagnostics

Diagnostics for examining logs in automated tests.

Using the logger With a WebApplicationFactory

The WithWebHostBuilder method on the factory allows you to configure the logging. Before setting up the web host, create a TestCaptureLoggerProvider in a place accessible from your test, then use in in the ConfigureLogging method, and run your test. After the test is run you can use the TestCaptureLoggerProvider to GetLogEntriesFor<T>() method to access the log entries that were made in the code under test.

e.g.

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[Test]
public void TestTheLogs()
{
  // Arrange: You need to set up the logProvider & add it to the WebApplicationFactory
  var logProvider = new TestCaptureLoggerProvider();
  using var factory = new WebApplicationFactory<Startup>()
    .WithWebHostBuilder(builder =>
    {
      builder.ConfigureLogging(loggingBuilder =>
      {
         loggingBuilder.AddProvider(logProvider);
      });
    });

  // Act : Do what ever you need to run your test

  // Assert : Check the logs for the conditions you expect
  var entries = logProvider.GetLogEntriesFor<T>();
  // entries[0].FormattedMessage.ShouldBe(...);
  // etc.
}