From 717a463a3ef8932b6258925122ae0443cae42518 Mon Sep 17 00:00:00 2001
From: Peter Byfield <peter.byfield@kraken.tech>
Date: Sat, 8 Feb 2025 17:11:05 +0100
Subject: [PATCH 1/4] CI: Split rust checks out from python checks

We don't need to run the rust tests for every single python version
in the matrix.
---
 .github/workflows/main.yml | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 686985d7..b141944c 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -9,8 +9,8 @@ on:
   workflow_dispatch:
 
 jobs:
-  tests:
-    name: Python ${{ matrix.python-version }}, ${{ matrix.os }}
+  check_python:
+    name: Check Python ${{ matrix.python-version }}, ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
 
     strategy:
@@ -22,14 +22,9 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: stable
-
-      - run: cargo test --no-default-features
-        working-directory: ./rust
-
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
@@ -43,6 +38,17 @@ jobs:
       - name: Run tox targets for ${{ matrix.python-version }}
         run: python -m tox
 
+  check_rust:
+    name: Check Rust
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+      - run: cargo test --no-default-features
+        working-directory: ./rust
+
   benchmarks:
       runs-on: ubuntu-22.04
       steps:

From 46635a9717055f316cafb57ad2d9aaa347b4880c Mon Sep 17 00:00:00 2001
From: Peter Byfield <peter.byfield@kraken.tech>
Date: Sat, 8 Feb 2025 17:16:51 +0100
Subject: [PATCH 2/4] CI: Add Clippy

Clippy is a very popular linter for rust code.
The default condifuration is good. Clippy can help us to
catch issues related to code correctness, style and performance.

https://doc.rust-lang.org/clippy/index.html
---
 .github/workflows/main.yml | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index b141944c..548780e7 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -46,7 +46,11 @@ jobs:
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: stable
-      - run: cargo test --no-default-features
+      - name: Run tests
+        run: cargo test --no-default-features
+        working-directory: ./rust
+      - name: Run linter (clippy)
+        run: cargo clippy --all-targets --all-features
         working-directory: ./rust
 
   benchmarks:

From 356627b7b7a25678cd79525f0bac9c8680e84e14 Mon Sep 17 00:00:00 2001
From: Peter Byfield <peter.byfield@kraken.tech>
Date: Sat, 8 Feb 2025 17:19:37 +0100
Subject: [PATCH 3/4] CI: Fail on clippy warnings

Most of the time clippy warnings are there for a reason and
it's best to restructure the code to avoid them. Clippy
can often apply automatic fixes with the `--fix` option.

In the rare case that clippy is wrong, lints can be ignored
at the module/function level.
---
 .github/workflows/main.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 548780e7..30ec463f 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -50,7 +50,7 @@ jobs:
         run: cargo test --no-default-features
         working-directory: ./rust
       - name: Run linter (clippy)
-        run: cargo clippy --all-targets --all-features
+        run: cargo clippy --all-targets --all-features -- -D warnings
         working-directory: ./rust
 
   benchmarks:

From c12e5f11bd7d9908c2925d40621b4783aea1688d Mon Sep 17 00:00:00 2001
From: Peter Byfield <peter.byfield@kraken.tech>
Date: Sat, 8 Feb 2025 17:29:28 +0100
Subject: [PATCH 4/4] Add note about rust code to the contributing guide

---
 CONTRIBUTING.rst | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/CONTRIBUTING.rst b/CONTRIBUTING.rst
index 5ecedfc5..472226dd 100644
--- a/CONTRIBUTING.rst
+++ b/CONTRIBUTING.rst
@@ -61,6 +61,16 @@ To set up `grimp` for local development:
 
 6. Submit a pull request through the GitHub website.
 
+Rust code
+---------
+
+When working with the rust code (in the ``rust/`` directory):
+
+* Run tests with ``cargo test --no-default-features``.
+  The ``--no-default-features`` flag is needed to due to `this PYO3 issue <https://pyo3.rs/main/faq#i-cant-run-cargo-test-or-i-cant-build-in-a-cargo-workspace-im-having-linker-issues-like-symbol-not-found-or-undefined-reference-to-_pyexc_systemerror>`_.
+* Run `clippy <https://doc.rust-lang.org/clippy/index.html>`_ (a linter for rust) with ``cargo clippy --all-targets --all-features -- -D warnings``.
+  It's often possible to apply automatic fixes to clippy issues with the ``--fix`` flag e.g. ``cargo clippy --all-targets --all-features --fix --allow-staged``.
+
 Pull Request Guidelines
 -----------------------