Source generators for command handlers #1362
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
@KathleenDollard yes I would would love to get together to go over this. My next steps are going to be to handle some of the error cases, and replace the C# string building. |
aa9a271 to
2f31e6d
Compare
efe8a7e to
fbe7493
Compare
40c3dc5 to
b742795
Compare
Disable nullable checks on generated code
b925a6e to
6f6c06f
Compare
jonsequitur
approved these changes
Sep 14, 2021
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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 a proof-of-concept just to solicit feedback. It is not a complete solution (yet?).
This leverages source generators to automatically build up command handlers.
The most interesting part of the solution is the GeneratedCommandHandlerTests.cs. This contains the tests to show how this works. Currently this adds in a new Generator property on the CommandHandlers class. This class is meaningless on its own, and only used as an anchor point for the source generator to look for. There are a couple "Generate" extension methods on this class (it is key that they are extension methods). When the generator sees a call to those Generate methods its generates a new extension method with better parameter matching to ensure that it will always be the one resolved. This is how it is able to build up the handlers at compile time.
There are lots of known failure cases, lots of things that have not been handled, and the source generator code is a mess.
Looking to know if this is an idea that is interesting enough to pursue and feedback on the approach.