ozziepeeps / ioptionsmonitorbug

Demonstrates a bug with IOptionsMonitor<T> in ASP.NET Core 3.1

IOptionsMonitorBug

Demonstrates a bug with IOptionsMonitor<T> in ASP.NET Core 3.1

TO REPRODUCE THE ISSUE:

1. Run the website
2. Hit the /ping endpoint from a browser - e.g. https://localhost:5001/ping
3. Observe that "MyValue = foo" is printed to the Console - "foo" is the value from appsettings.json
4. While the site is running, change the value of "foo" in appsettings.json to "bar"
5. Hit the /ping endpoint again from a browser - e.g. https://localhost:5001/ping
6. Observe that "MyValue = foo" is printed to the Console again. This value is stale

EXPECTED RESULT: "MyValue = bar" should be printed to the Console, since that is the latest value in configuration and IOptionsMonitor<T> should have detected the change to the file.

ACTUAL RESULT: The stale value "MyValue = foo" is printed.

OTHER NOTES: If you look at Startup.cs - lines 16/17 - if you use GetSection (line 17) instead of Bind (line 16), then things work as expected - the change of configuration value to "bar" is detected. I believe it should also work as desired using Bind.