BackendFixture fails with Sanic because missing test_mode

[ahopkins]

The problem was reported here: sanic-org/sanic#2643.

The issue is that the BackendFixture for testing Sanic does not set Sanic.test_mode = True, which means that there is potential for issues (as seen the linked issue) to arise. I propose that you add this into your test implementation for Sanic to automatically manage setting that variable.

[Archmonger]

Are there any security implications to using test_mode?

[rmorshea]

This is purely related to IDOM's test tooling. I was planning on setting this when creating a development app instance for Sanic.

[ahopkins]

No security concerns. When Sanic starts up, one of the things that it does is some self-inspection of the application and actually rewrites some class methods to optimize for the task at hand. One of the things test_mode does (and was the issue in the link above) is make this process more lenient and fault tolerant. Something you will need when you are constantly standing up the same application in the same interpreter.