Why does this fragment of code not work? (IConfiguration, IChangeToken)

[DrkWzrd]

I'm driving myself crazy because this must work, right?

This run is a test in a desktop environment.

[Fact]
public void FileChangeShouldUpdateConfiguration()
{
	var cBuilder = new ConfigurationBuilder();
	cBuilder.AddJsonFile("config.json", false, true);
	var config = cBuilder.Build();
	var token = config.GetReloadToken();
	token.RegisterChangeCallback((c) =>
	{
		//this fragment is never called, and the configuration never reloads on his own
	}, null);

	var value = config["database_config:port"];

	var jsonOriginalText = File.ReadAllText($"{Environment.CurrentDirectory}/config.json");
	
        var jobject = JsonNode.Parse(jsonOriginalText);
	jobject!["database_config:port"] = Random.Shared.Next(0, 10000);

	File.WriteAllText($"{Environment.CurrentDirectory}/config.json", jobject.ToJsonString());

	var jsonNewText = File.ReadAllText($"{Environment.CurrentDirectory}/config.json");

	var newVal = config["database_config:port"];

	Assert.NotEqual(value, newVal);

}

No exceptions, no problems, only the configuration never updates itself. If I call Reload() then it works.

[KeterSCP]

Seems like ConfigurationBuilder uses FileSystemWatcher to detect changes on configs. And it can fire events with some delay and not immediately after a file was written. You can see that by simply adding Thread.Sleep(500); after File.WriteAllText

[DrkWzrd]

Despite of that being annoying, is the only way for the test to work always. Using a Thread.Sleep or Task.Delay (in async) with a number bigger (100-200 more) than the ReloadDelay. Even when the ReloadDelay is 0, the race must be controlled.

In non-test code, the callback is called, eventually.

This should be more clear in the docs, or it should be more instantaneous.