Explicitly declare directly used dependency features

[ChihweiLHBird]

Summary

This PR makes dependency feature declarations match the APIs Spin uses directly, instead of relying on those features being enabled by other crates in the dependency graph.

It also narrows a few existing Tokio declarations so production dependencies only carry the features used by production code, with test-only runtime features moved to dev-dependencies.

It may be helpful to prevent future confusion like this.

Fully resolve this kind of issue requires work on the Cargo side: rust-lang/cargo#14375

Direct feature usage

• reqwest/json for root integration tests: resp.json() and .json(&body).
• clap/derive for spin-trigger-http: #[derive(Args)].
• clap/env for spin-trigger-http: #[clap(..., env = ...)].
• hyper-util/client-legacy for spin-factor-outbound-http: hyper_util::client::legacy::{Client, connect::*}.
• hyper-util/http1 for spin-factor-outbound-http: the HTTP/1 client build path.
• hyper-util/http2 for spin-factor-outbound-http: http2_only(true).
• tokio/fs for spin-dependency-wit: tokio::fs::remove_file, create_dir_all, write, and read.
• tokio/fs for spin-environments: tokio::fs::read_to_string and tokio::fs::read.
• tokio/sync for spin-environments: tokio::sync::RwLock.
• tokio/time for spin-environments: tokio::time::timeout.
• tokio/net for spin-factor-outbound-http: tokio::net::lookup_host.
• tokio/rt for spin-factor-outbound-http: tokio::task_local!.
• tokio/time for spin-factor-outbound-http: tokio::time::Sleep and tokio::time::sleep.
• tokio/macros and tokio/rt-multi-thread for spin-factor-outbound-http tests: #[tokio::test(flavor = "multi_thread")].
• tokio/rt for spin-factor-outbound-mysql: tokio::spawn.
• tokio/sync for spin-factor-outbound-mysql: tokio::sync::{Mutex, mpsc, oneshot}.
• tokio/macros and tokio/rt for spin-factor-outbound-mysql tests: #[tokio::test].
• tokio/sync for spin-factor-sqlite: tokio::sync::{mpsc, oneshot}.
• tokio/macros and tokio/rt-multi-thread for spin-factor-variables tests: #[tokio::test(flavor = "multi_thread")].
• tokio/rt for spin-key-value-aws: tokio::spawn.
• tokio/sync for spin-key-value-aws: tokio::sync::{mpsc, oneshot}.
• tokio/rt for spin-key-value-azure: tokio::spawn.
• tokio/sync for spin-key-value-azure: tokio::sync::{mpsc, oneshot}.
• tokio/rt for spin-key-value-redis: tokio::spawn.
• tokio/sync for spin-key-value-redis: tokio::sync::OnceCell and mpsc / oneshot.
• tokio/rt for spin-key-value-spin: tokio::task::spawn_blocking.
• tokio/sync for spin-key-value-spin: tokio::sync::{mpsc, oneshot}.
• tokio/macros and tokio/rt-multi-thread for spin-key-value-spin tests: #[tokio::test(flavor = "multi_thread", worker_threads = 1)].
• tokio/fs for spin-llm-local: tokio::fs::read_dir.
• tokio/rt for spin-llm-local: tokio::task::spawn_blocking.
• tokio/fs for spin-loader: tokio::fs::write.
• tokio/io-util for spin-loader: tokio::io::AsyncWriteExt.
• tokio/sync for spin-loader: tokio::sync::Semaphore.
• tokio/fs for spin-oci: tokio::fs::read_to_string, tokio::fs::read, and tokio::fs::write.
• tokio/io-util for spin-oci: tokio::io::AsyncWriteExt.
• tokio/rt for spin-oci: tokio::task::spawn_blocking.
• tokio/macros and tokio/rt for spin-oci tests: #[tokio::test].
• tokio/macros and tokio/rt-multi-thread for spin-runtime-config tests: #[tokio::test(flavor = "multi_thread", worker_threads = 1)].
• tokio/rt for spin-sqlite-inproc: tokio::task::spawn_blocking.
• tokio/sync for spin-sqlite-inproc: tokio::sync::{oneshot, mpsc}.
• tokio/macros and tokio/rt for spin-app, spin-dependency-wit, spin-environments, spin-loader, and spin-trigger tests: examples include crates/app/src/lib.rs, crates/dependency-wit/src/lib.rs, crates/environments/src/environment.rs, crates/loader/src/cache.rs, and crates/trigger/src/cli/sqlite_statements.rs.
• tokio/sync for spin-trigger tests: tokio::sync::{mpsc, oneshot}.
• tokio/sync for spin-wasi-async: tokio::sync::mpsc::Receiver.

Notes

• spin-dependency-wit, spin-key-value-spin, spin-llm-local, and spin-factor-outbound-mysql
  were narrowed where the previous declaration was broader than direct source usage required.
• Test-only Tokio runtime support is declared as dev-dependencies where possible.

Test commands

cargo check -p spin-dependency-wit -p spin-environments -p spin-factor-outbound-http \
  -p spin-factor-outbound-mysql -p spin-factor-variables -p spin-key-value-spin \
  -p spin-llm-local -p spin-oci -p spin-runtime-config -p spin-trigger --tests
cargo check -p spin-cli --test integration

[itowlson]

Does the test work? I tried running cargo check -p on a couple of these packages in main, and it didn't report any problems, so I am not sure that it will pick up missing features. If it does work, then we should add it to CI, because otherwise, these sorts of misalignments will just creep back.

[ChihweiLHBird]

Hi @itowlson, that command is mostly for checking whether this PR broke dependencies. Currently, without Cargo work, there isn't a way to check whether the features used in spin code are explicitly declared in Cargo.toml in the current main branch.