fix(steer): enforce fail-fast assertion for empty service iterators#866
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Alpy16 wants to merge 2 commits into
Open
fix(steer): enforce fail-fast assertion for empty service iterators#866Alpy16 wants to merge 2 commits into
Alpy16 wants to merge 2 commits into
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Closes #859
Description
Initializing Steer with an empty collection of services leaves the routing middleware in an unresolvable invariant state. While poll_ready will trivially return Poll::Ready(Ok(())), any subsequent invocation of call will immediately panic because there are no underlying target services to route the request to.
This patch adds an explicit assert!(!services.is_empty(), ...) check to the Steer::new constructor, shifting an operational runtime risk into a fast, upfront failure.
Type of Change
Bug fix (non-breaking change enforcing defensive API boundaries)
Verification
Added a #[should_panic] integration test in tower/tests/steer/main.rs with explicit type hinting to satisfy the compiler's inference engine.
Verified workspace tests pass via cargo test --test steer --all-features.