ExtensionContext API feedback

[keturn]

I was surprised that the ExtensionContext provided to postProcessInstance has neither Method nor Instance in it.

With a lifecycle of PER_METHOD, I expected every instance to have a corresponding method.

Yes, postProcess does receive an instance parameter independently of its context,
but I am trying to share code with a ParameterResolver.
I fear it will be messy to teach that code that sometimes the ExtensionContext is sufficient
and sometimes it needs AdditionalStuffBeyondContext.

My goal is to have have a resource in ExtensionContext.Store with the same lifespan as
the TestInstance Lifecycle. Sounds like a simple use case but I'm tripping over a lot of ways to do it wrong.

[keturn]

Ah, I see now that reading the fine print tells you that it has no Instance.

junit5/junit-jupiter-api/src/main/java/org/junit/jupiter/api/extension/TestInstancePostProcessor.java

Lines 43 to 55 in 1150d6b

	/**
	* Callback for post-processing the supplied test instance.
	*
	* <p><strong>Note</strong>: the {@code ExtensionContext} supplied to a
	* {@code TestInstancePostProcessor} will always return an empty
	* {@link java.util.Optional} value from {@link ExtensionContext#getTestInstance()
	* getTestInstance()}. A {@code TestInstancePostProcessor} should therefore
	* only attempt to process the supplied {@code testInstance}.
	*
	* @param testInstance the instance to post-process; never {@code null}
	* @param context the current extension context; never {@code null}
	*/
	void postProcessTestInstance(Object testInstance, ExtensionContext context) throws Exception;

so at least it's documented, but it's still awkward to use