Adopt the Whitaker Dylint suite in the lint gate and CI

.github/workflows/ci.yml

@@ -13,6 +13,7 @@ jobs:
     env:
       CARGO_TERM_COLOR: always
       BUILD_PROFILE: debug
+      WHITAKER_INSTALLER_VERSION: '0.2.5'
     steps:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8
       - name: Install system dependencies
@@ -30,6 +31,24 @@ jobs:
             **/*.md
             !**/target/**
             !**/dist/**
+      - name: Cache whitaker-installer
+        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830  # v4.3.0
+        with:
+          path: |
+            ~/.cargo/bin/whitaker-installer
+            ~/.cache/cargo-binstall
+          key: whitaker-installer-${{ runner.os }}-${{ runner.arch }}-${{ env.WHITAKER_INSTALLER_VERSION }}
+      - name: Install the Whitaker Dylint suite
+        run: |
+          if ! command -v whitaker-installer >/dev/null 2>&1; then
+            if cargo binstall --version >/dev/null 2>&1; then
+              cargo binstall --no-confirm --locked "whitaker-installer@${WHITAKER_INSTALLER_VERSION}"
+            else
+              echo "cargo-binstall unavailable; building whitaker-installer from crates.io"
+              cargo install --locked whitaker-installer --version "${WHITAKER_INSTALLER_VERSION}"
+            fi
+          fi
+          whitaker-installer
       - name: Lint
         run: make lint
       - name: Test and Measure Coverage

Cargo.toml

@@ -20,6 +20,7 @@ tracing-subscriber = { version = "0.3.18", features = ["env-filter", "fmt"] }
 dashmap = "6.2.1"
 metrics = "0.22.4"
 metrics-exporter-prometheus = "0.13.1"
+cap-std = "4.0.2"
 
 [dev-dependencies]
 assert_cmd = "2.0.16"

Makefile

@@ -6,6 +6,7 @@ BUILD_JOBS ?=
 CLIPPY_FLAGS ?= --all-targets --all-features -- -D warnings
 MDLINT ?= markdownlint-cli2
 NIXIE ?= nixie
+WHITAKER ?= whitaker
 
 build: target/debug/$(APP) ## Build debug binary
 release: target/release/$(APP) ## Build release binary
@@ -21,8 +22,9 @@ test: ## Run tests with warnings treated as errors
 target/%/$(APP): ## Build binary in debug or release mode
 	$(CARGO) build $(BUILD_JOBS) $(if $(findstring release,$(@)),--release) --bin $(APP)
 
-lint: ## Run Clippy with warnings denied
+lint: ## Run Clippy and the Whitaker Dylint suite with warnings denied
 	$(CARGO) clippy --all-targets --all-features -- -D warnings
+	RUSTFLAGS="-D warnings" $(WHITAKER) --all -- --all-targets --all-features
 
 typecheck: ## Run cargo check for fast no-link verification
 	$(CARGO) check --all-targets $(BUILD_JOBS)

README.md

@@ -84,8 +84,22 @@ directories.
 Fast feedback is available through:
 
 - `cargo fmt` for formatting checks.
-- `cargo clippy --all-targets --all-features -- -D warnings` for linting.
+- `make lint` for linting, which runs Clippy
+  (`cargo clippy --all-targets --all-features -- -D warnings`) followed by the
+  [Whitaker](https://github.com/leynos/whitaker) Dylint suite with warnings
+  denied.
 - `cargo test` for unit tests built with `rstest` and `tokio`.
 
+Linting requires the Whitaker suite. Install it with
+[`whitaker-installer`](https://github.com/leynos/whitaker):
+
+```bash
+cargo binstall --no-confirm --locked whitaker-installer  # or: cargo install --locked whitaker-installer
+whitaker-installer
+```
+
+This provisions the pinned toolchain, `cargo-dylint`, and the `whitaker`
+wrapper used by `make lint`.
+
 The rate limiter depends on the `mockable` clock abstraction, enabling
 deterministic control of timestamps in the test suite.

src/config.rs

@@ -153,7 +153,10 @@ fn ensure_directory(path: &Path) -> Result<()> {
             path.display()
         ));
     }
-    std::fs::create_dir_all(path)
+    // Creating the store root from operator-supplied configuration is the one
+    // ambient filesystem operation the server performs; cap-std makes that
+    // ambient authority explicit.
+    cap_std::fs::Dir::create_ambient_dir_all(path, cap_std::ambient_authority())
         .with_context(|| format!("failed to create store root {}", path.display()))?;
     Ok(())
 }

src/framing.rs

@@ -36,6 +36,7 @@ pub fn trim_line_endings(line: &str) -> &str {
 
 #[cfg(test)]
 mod tests {
+    //! Unit tests for finger response framing and line endings.
     use super::*;
     use rstest::rstest;
 

src/identity.rs

@@ -119,6 +119,7 @@ impl fmt::Display for HostName {
 
 #[cfg(test)]
 mod tests {
+    //! Unit tests for username and hostname validation.
     use super::*;
     use rstest::rstest;
 

src/main.rs

@@ -20,10 +20,18 @@ use server::FingerServer;
 use storage::ObjectStoreUserStore;
 use tracing_subscriber::EnvFilter;
 
-#[tokio::main]
-async fn main() -> Result<()> {
+fn main() -> Result<()> {
     install_tracing();
 
+    // Build the runtime explicitly so runtime construction errors propagate
+    // instead of panicking inside the `#[tokio::main]` expansion.
+    let runtime = tokio::runtime::Builder::new_multi_thread()
+        .enable_all()
+        .build()?;
+    runtime.block_on(run())
+}
+
+async fn run() -> Result<()> {
     let cli = CliOptions::parse();
     let config = ServerConfig::from_cli(cli)?;
     let metrics_endpoint = telemetry::install_metrics(config.metrics_listen).await?;

src/query.rs

@@ -135,6 +135,7 @@ impl FingerQuery {
 
 #[cfg(test)]
 mod tests {
+    //! Unit tests for finger query parsing.
     use super::*;
     use rstest::rstest;
 

src/rate_limit.rs

@@ -175,6 +175,7 @@ fn chrono_duration(window: Duration) -> ChronoDuration {
 
 #[cfg(test)]
 mod tests {
+    //! Unit tests for the per-client rate limiter.
     use super::*;
     use std::sync::Mutex as StdMutex;
 

src/server.rs

@@ -214,6 +214,7 @@ fn render_message(message: &str) -> Vec<u8> {
 
 #[cfg(test)]
 mod tests {
+    //! Unit tests for finger server request handling.
     use super::*;
     use crate::identity::{HostName, Username};
     use crate::rate_limit::RateLimitSettings;

src/storage.rs

@@ -146,18 +146,20 @@ fn trim_slashes(input: impl AsRef<str>) -> String {
 
 #[cfg(test)]
 mod tests {
+    //! Behavioural tests for the object-store backed user repository.
     use super::*;
     use crate::identity::Username;
     use anyhow::{Result, anyhow};
+    use cap_std::fs::Dir;
     use object_store::local::LocalFileSystem;
     use rstest::rstest;
     use tempfile::TempDir;
 
-    fn write_file(path: &std::path::Path, contents: &str) -> Result<()> {
-        if let Some(parent) = path.parent() {
-            std::fs::create_dir_all(parent)?;
+    fn write_file(root: &Dir, relative: &str, contents: &str) -> Result<()> {
+        if let Some((parent, _)) = relative.rsplit_once('/') {
+            root.create_dir_all(parent)?;
         }
-        std::fs::write(path, contents)?;
+        root.write(relative, contents)?;
         Ok(())
     }
 
@@ -224,15 +226,17 @@ mod tests {
     async fn load_user_behaviour(#[case] case: LoadCase) -> Result<()> {
         let tmp = TempDir::new()?;
         let root = tmp.path();
+        let root_dir = Dir::open_ambient_dir(root, cap_std::ambient_authority())?;
 
         if let Some(user) = &case.existing_user {
             // mirror production repository layout so we exercise the full IO path
             write_file(
-                &root.join(format!("profiles/{}.toml", user.username)),
+                &root_dir,
+                &format!("profiles/{}.toml", user.username),
                 user.profile,
             )?;
             if let Some(plan) = user.plan {
-                write_file(&root.join(format!("plans/{}.plan", user.username)), plan)?;
+                write_file(&root_dir, &format!("plans/{}.plan", user.username), plan)?;
             }
         }