breaking: remove the Handler and StateManager traits

[danieleades]

What changed

• remove the Handler and StateManager traits
• make MockServer and HttpMockHandler concrete, so HttpMockServer becomes a real type rather than an alias over internal generics
• rename HttpMockHandler to handler::Handler, HttpMockStateManager to state::Manager, and MockServerState to a private state::Inner
• make HttpMockServer::new infallible and pub(crate)
• remove private_bounds from the temporary allow list

Why

private_bounds fired four times because pub type HttpMockServer = MockServer<HttpMockHandler<HttpMockStateManager>> made both generics publicly reachable while their bounds were pub(crate).

Keeping the traits and just hiding the structs does not work: it trades the four private_bounds errors for four private_interfaces ones, because HttpMockServerBuilder::build is public and returns the server. The options were to export a 22-method trait publicly forever, or to stop pretending the generics were doing anything.

They were not. Each trait had exactly one implementor and neither is dyn compatible, StateManager::record being generic and Handler::handle returning impl Future, so neither could ever have been a dynamic dispatch seam. Nothing substitutes an alternative state manager or handler, including the tests. Manager is a pure in-memory type over a Mutex, with no I/O to fake.

Dropping them also frees the good names. Handler and Manager were only spelled HttpMockHandler and HttpMockStateManager because the traits held those names, and state::Inner is the conventional spelling for data guarded by a lock. HttpMockServer keeps its prefix, since httpmock::MockServer is already the client-side handle.

Breaking changes

• httpmock::server::state::HttpMockStateManager is now state::Manager
• httpmock::server::state::MockServerState is now private
• HttpMockServer is a struct rather than a type alias, and HttpMockServer::new is pub(crate)

Nothing that was callable downstream has been removed. MockServer::new took an unnameable argument type, and every Manager method other than new and default was already behind a pub(crate) trait. Construction still goes through HttpMockServerBuilder, and start, start_with_signals and run_accept_loop are unchanged. Runtime behavior is unchanged.

Validation

• cargo clippy --all-targets --all-features
• cargo clippy --all-targets
• cargo clippy --all-targets --no-default-features
• cargo clippy --all-targets --features standalone
• cargo hack check --feature-powerset --depth 2 --all-targets
• cargo hack check --rust-version --each-feature --no-dev-deps on 1.88
• cargo test --all-features
• cargo fmt --all -- --check
• git diff --check

[codecov]

Codecov Report

❌ Patch coverage is 94.59459% with 4 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/server/state.rs	90.62%	3 Missing ⚠️
src/server/persistence.rs	0.00%	1 Missing ⚠️

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