output-bindings property does not work for bindings definition

[Ferioney]

After upgrading from Spring Cloud 2021 to 2024, I faced the issue with spring.cloud.stream.output-bindings property.

Configuration:

spring:
  cloud:
    stream:
      output-bindings: demo-test
      bindings:
        demo-test-out-0:
          destination: demo_topics
          content-type: application/json
          producer:
            header-mode: none
          binder: kafka

With SC 2021 topic demo_topics was created and used.
With SC 2024 (and 2023) demo_topics was not used, and topic with name demo-test was created.

I prepared a demo to reproduce the issue.
Configuration: application-test.yml.
Function test: TopicsInUse.
SC 2021 branch: cloud2021 pom.xml
SC 2024 branch: cloud2024 pom.xml

[olegz]

Actually, this is a bug in documentation. The reality is that we simply no longer apply the in-0/out-0 suffices given that explicit binding declaration is already either input or output and can only have a single input or output.
IN any event, I am updating documentation and will push shortly .

For your case simply change

bindings:
        demo-test-out-0:

to

bindings:
        demo-test: