ci(rust): split rust jobs, use nextest and Swatinem/rust-cache

Split the Rust workflow into fmt, clippy, nextest and wheel jobs so they run in parallel, replace manual actions/cache with Swatinem/rust-cache, and install a pinned checksum-verified cargo-nextest. Make two python-bridge tests self-contained so they pass when nextest runs each test in its own process.

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

.github/workflows/test-rust.yml

@@ -68,9 +68,9 @@ env:
   CARGO_TERM_COLOR: always
 
 jobs:
-  rust-lint:
+  rust-fmt:
     runs-on: ubuntu-latest
-    timeout-minutes: 10
+    timeout-minutes: 5
     defaults:
       run:
         working-directory: litellm-rust
@@ -81,24 +81,67 @@ jobs:
 
       - run: rustup toolchain install --no-self-update
 
-      - run: cargo fmt --check
+      - run: cargo fmt --all --check
 
-      - uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4.3.0
+  rust-clippy:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    defaults:
+      run:
+        working-directory: litellm-rust
+    steps:
+      - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
         with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-            litellm-rust/target
-          key: ${{ runner.os }}-cargo-${{ github.job }}-${{ hashFiles('rust-toolchain.toml', '.cargo/**', 'litellm-rust/Cargo.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-cargo-${{ github.job }}-
+          persist-credentials: false
+
+      - run: rustup toolchain install --no-self-update
+
+      - uses: Swatinem/rust-cache@6323deb102c322ba6fcbdcafc7e3dddab59af2b6 # v2.9.2
+        with:
+          workspaces: litellm-rust
+          cache-on-failure: true
 
       - run: cargo clippy --workspace --all-targets --locked -- -D warnings
 
   rust-test:
     runs-on: ubuntu-latest
-    timeout-minutes: 30
+    timeout-minutes: 20
+    defaults:
+      run:
+        working-directory: litellm-rust
+    steps:
+      - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+        with:
+          persist-credentials: false
 
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+        with:
+          python-version: "3.12"
+
+      - run: rustup toolchain install --no-self-update
+
+      - name: Install cargo-nextest 0.9.143
+        working-directory: ${{ runner.temp }}
+        run: |
+          curl -fsSL --retry 3 -o cargo-nextest.tar.gz \
+            https://github.com/nextest-rs/nextest/releases/download/cargo-nextest-0.9.143/cargo-nextest-0.9.143-x86_64-unknown-linux-gnu.tar.gz
+          echo "66786b9abe23920d022a182d1416b1bbc8130dd4872a9553d76985a1708dcd1e  cargo-nextest.tar.gz" | sha256sum -c -
+          mkdir -p bin
+          tar xzf cargo-nextest.tar.gz -C bin cargo-nextest
+          echo "$PWD/bin" >> "$GITHUB_PATH"
+
+      - uses: Swatinem/rust-cache@6323deb102c322ba6fcbdcafc7e3dddab59af2b6 # v2.9.2
+        with:
+          workspaces: litellm-rust
+          cache-on-failure: true
+
+      - run: cargo nextest run --workspace --locked
+
+      - run: cargo test --workspace --doc --locked
+
+  rust-wheel:
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
     steps:
       - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
         with:
@@ -114,18 +157,10 @@ jobs:
 
       - run: rustup toolchain install --no-self-update
 
-      - uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4.3.0
+      - uses: Swatinem/rust-cache@6323deb102c322ba6fcbdcafc7e3dddab59af2b6 # v2.9.2
         with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-            litellm-rust/target
-          key: ${{ runner.os }}-cargo-${{ github.job }}-${{ hashFiles('rust-toolchain.toml', '.cargo/**', 'litellm-rust/Cargo.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-cargo-${{ github.job }}-
-
-      - run: cargo test --workspace --locked
-        working-directory: litellm-rust
+          workspaces: litellm-rust
+          cache-on-failure: true
 
       - run: uv build --wheel --out-dir dist
 

litellm-rust/crates/python-bridge/src/lifecycle/mod.rs

@@ -599,6 +599,34 @@ mod tests {
 
     static PYTHON_GLOBALS: Mutex<()> = Mutex::new(());
 
+    fn install_lifecycle_module(py: Python<'_>) -> Bound<'_, PyModule> {
+        py.run(
+            pyo3::ffi::c_str!(
+                r#"
+import sys
+import types
+
+sys.modules.setdefault('litellm', types.ModuleType('litellm'))
+sys.modules.setdefault('litellm.rust_bridge', types.ModuleType('litellm.rust_bridge'))
+"#
+            ),
+            None,
+            None,
+        )
+        .unwrap();
+        let source = std::ffi::CString::new(include_str!(
+            "../../../../../litellm/rust_bridge/lifecycle.py"
+        ))
+        .unwrap();
+        PyModule::from_code(
+            py,
+            &source,
+            pyo3::ffi::c_str!("lifecycle.py"),
+            pyo3::ffi::c_str!("litellm.rust_bridge.lifecycle"),
+        )
+        .unwrap()
+    }
+
     fn install_logging_worker(py: Python<'_>, worker: &Bound<'_, PyAny>) -> PyResult<()> {
         py.import("litellm.litellm_core_utils.logging_worker")?
             .setattr("GLOBAL_LOGGING_WORKER", worker)
@@ -773,17 +801,7 @@ mod tests {
             .unwrap_or_else(|error| error.into_inner());
         Python::initialize();
         Python::attach(|py| {
-            let source = std::ffi::CString::new(include_str!(
-                "../../../../../litellm/rust_bridge/lifecycle.py"
-            ))
-            .unwrap();
-            PyModule::from_code(
-                py,
-                &source,
-                pyo3::ffi::c_str!("lifecycle.py"),
-                pyo3::ffi::c_str!("litellm.rust_bridge.lifecycle"),
-            )
-            .unwrap();
+            install_lifecycle_module(py);
             let route = SyntheticRoute(
                 PythonCallState::new(
                     py,
@@ -819,17 +837,7 @@ mod tests {
         Python::initialize();
         Python::attach(|py| {
             py.import("asyncio").unwrap();
-            let source = std::ffi::CString::new(include_str!(
-                "../../../../../litellm/rust_bridge/lifecycle.py"
-            ))
-            .unwrap();
-            let module = PyModule::from_code(
-                py,
-                &source,
-                pyo3::ffi::c_str!("lifecycle.py"),
-                pyo3::ffi::c_str!("litellm.rust_bridge.lifecycle"),
-            )
-            .unwrap();
+            let module = install_lifecycle_module(py);
             let locals = PyDict::new(py);
             locals
                 .set_item("drive", module.getattr("drive").unwrap())

litellm-rust/crates/python-bridge/src/marshal.rs

@@ -190,6 +190,7 @@ mod tests {
 
     #[test]
     fn required_shapes_preserve_nested_values_and_existing_errors() {
+        Python::initialize();
         let nested = json!([{"role": "user", "content": [{"type": "text", "text": "hi"}]}]);
         assert_eq!(
             Value::Array(required_array("messages", nested.clone()).unwrap()),