Add pre-commit hooks

.pre-commit-config.yaml

@@ -0,0 +1,24 @@
+# See https://pre-commit.com for more information
+# See https://pre-commit.com/hooks.html for more hooks
+
+default_stages: [commit]
+
+repos:
+  - repo: local
+    hooks:
+      - id: cargo-fmt
+        name: cargo format
+        entry: cargo
+        language: system
+        types: [file, rust]
+        pass_filenames: false
+        description: Runs cargo fmt on the codebase.
+        args: [fmt]
+      - id: cargo-clippy
+        name: cargo clippy
+        entry: cargo
+        language: system
+        types: [file, rust]
+        pass_filenames: false
+        description: Runs cargo clippy on the codebase.
+        args: [clippy]

README.md

@@ -25,6 +25,15 @@ The resulting ELF file will be located under `target/thumbv7em-none-eabihf/relea
 
 Alternatively, you can install the Rust toolchain without Nix using rustup; see the Rust manifest file pulled in `flake.nix` to determine which Rust version to use.
 
+#### Pre-Commit Hooks
+
+You are strongly recommended to use the provided pre-commit hooks to automatically reformat files and check for non-optimal Rust practices using Clippy. Run pre-commit install to install the hook and pre-commit will automatically run cargo fmt and cargo clippy for you.
+
+Several things to note:
+
+    If cargo fmt or cargo clippy returns an error, the pre-commit hook will fail. You should fix all errors before trying to commit again.
+    If cargo fmt reformats some files, the pre-commit hook will also fail. You should review the changes and, if satisfied, try to commit again.
+
 ## Debugging
 
 Connect SWDIO/SWCLK/RST/GND to a programmer such as ST-Link v2.1. Run OpenOCD:

flake.nix

@@ -64,6 +64,7 @@
         packages = with pkgs; [
           rust llvm
           openocd dfu-util
+          pre-commit
           ] ++ (with python3Packages; [
             numpy matplotlib
           ]);