Fixes #1661 - Make IDocumentFilter async compatible #2635
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This is my take on the fix for this. Rather than extending IDocumentFilter, I created a new IDocumentAsyncFilter that is configured separately. I chosen to name IDocumentAsyncFilter to help make it clearer for developers. It continues to use a method named "Apply" like other filters, and since they Type itself makes it clear that it is for Async, I did not name the method "ApplyAsync". In cases where GetSwaggerAsync() is called, the IDocumentFilters will run first and then the IDocumentAsyncFilters. For GetSwagger(), only the IDocumentFilters are run. If IDocumentAsyncFilters are configured, it will throw an exception stating to use GetSwaggerAsync() instead.
I had also considered just extending the IDocumentFilter to interface to have an async ApplyAsync() method with a default implementation, but that was not possible with the targeted runtimes.