docs(iroh): improved feature flag documentation

.github/workflows/ci.yml

@@ -105,7 +105,7 @@ jobs:
 
   check_fmt_and_docs:
     timeout-minutes: 30
-    name: Checking fmt and docs
+    name: Checking fmt
     runs-on: ubuntu-latest
     env:
       RUSTC_WRAPPER: "sccache"
@@ -123,8 +123,23 @@ jobs:
     - name: fmt
       run: cargo fmt --all -- --check
 
+    name: Checking docs
+    runs-on: ubuntu-latest
+    env:
+      RUSTC_WRAPPER: "sccache"
+      SCCACHE_GHA_ENABLED: "on"
+    steps:
+    - uses: actions/checkout@v4
+    - uses: dtolnay/rust-toolchain@stable
+      with:
+        toolchain: nightly-2024-05-02
+    - name: Install sccache
+      uses: mozilla-actions/[email protected]
+
     - name: Docs
       run: cargo doc --workspace --all-features --no-deps --document-private-items
+      env:
+        RUSTDOCFLAGS: --cfg docsrs
 
   clippy_check:
     timeout-minutes: 30

iroh/Cargo.toml

@@ -76,6 +76,12 @@ testdir = "0.9.1"
 tokio = { version = "1", features = ["macros", "io-util", "rt"] }
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 
+[package.metadata.docs.rs]
+all-features = true
+# enable unstable features in the documentation
+rustdoc-args = ["--cfg", "docsrs"]
+
+
 [[example]]
 name = "hello-world-provide"
 

iroh/src/lib.rs

@@ -1,4 +1,11 @@
 //! Send data over the internet.
+//!
+//! ## Feature Flags
+//!
+//! - `metrics`: Enable metrics collection
+//! - `fs-store`: Enables the disk based storage backend for `iroh-bytes`.
+//!
+#![cfg_attr(docsrs, feature(doc_cfg))]
 #![deny(missing_docs, rustdoc::broken_intra_doc_links)]
 
 // re-export the iroh crates
@@ -20,4 +27,5 @@ mod sync_engine;
 
 /// Expose metrics module
 #[cfg(feature = "metrics")]
+#[cfg_attr(all(docsrs, feature = "metrics"), doc(cfg(feature = "metrics")))]
 pub mod metrics;