chore: Add rustfmt config (#956)

* chore: Add rustfmt config, apply formatting to code

* chore: Adjust pre-commit config file

Pre-commit now uses a local hook to validate formatting of Rust code.

* ci: Use nightly toolchain for pre-commit workflow

* test: Fix stderr output after test code changes

* chore: Apply suggestion

Co-authored-by: Sebastian Bernauer <sebastian.bernauer@stackable.de>

---------

Co-authored-by: Sebastian Bernauer <sebastian.bernauer@stackable.de>

Author: Techassi

.github/workflows/pr_pre-commit.yaml

@@ -6,7 +6,7 @@ on:
 
 env:
   CARGO_TERM_COLOR: always
-  RUST_TOOLCHAIN_VERSION: "1.82.0"
+  RUST_TOOLCHAIN_VERSION: "nightly-2025-01-15"
   HADOLINT_VERSION: "v1.17.6"
 
 jobs:

.pre-commit-config.yaml

@@ -15,8 +15,6 @@ repos:
   - repo: https://github.com/doublify/pre-commit-rust
     rev: eeee35a89e69d5772bdee97db1a6a898467b686e # 1.0
     hooks:
-      - id: fmt
-        args: ["--all", "--", "--check"]
       - id: clippy
         args: ["--all-targets", "--", "-D", "warnings"]
   - repo: https://github.com/adrienverge/yamllint
@@ -53,3 +51,11 @@ repos:
         entry: .scripts/verify_crate_versions.sh
         stages: [pre-commit, pre-merge-commit, manual]
         pass_filenames: false
+
+      - id: rustfmt
+        name: rustfmt
+        language: system
+        # Pinning to a specific rustc version, so that we get consistent formatting
+        entry: cargo +nightly-2025-01-15 fmt --all -- --check
+        stages: [pre-commit]
+        pass_filenames: false

crates/k8s-version/src/api_version.rs

@@ -1,9 +1,8 @@
 use std::{cmp::Ordering, fmt::Display, str::FromStr};
 
-use snafu::{ResultExt, Snafu};
-
 #[cfg(feature = "darling")]
 use darling::FromMeta;
+use snafu::{ResultExt, Snafu};
 
 use crate::{Group, ParseGroupError, ParseVersionError, Version};
 
@@ -102,13 +101,12 @@ impl ApiVersion {
 
 #[cfg(test)]
 mod test {
-    use super::*;
-    use crate::Level;
-
-    use rstest::rstest;
-
     #[cfg(feature = "darling")]
     use quote::quote;
+    use rstest::rstest;
+
+    use super::*;
+    use crate::Level;
 
     #[cfg(feature = "darling")]
     fn parse_meta(tokens: proc_macro2::TokenStream) -> ::std::result::Result<syn::Meta, String> {

crates/k8s-version/src/level.rs

@@ -7,11 +7,10 @@ use std::{
     sync::LazyLock,
 };
 
-use regex::Regex;
-use snafu::{OptionExt, ResultExt, Snafu};
-
 #[cfg(feature = "darling")]
 use darling::FromMeta;
+use regex::Regex;
+use snafu::{OptionExt, ResultExt, Snafu};
 
 static LEVEL_REGEX: LazyLock<Regex> = LazyLock::new(|| {
     Regex::new(r"^(?P<identifier>[a-z]+)(?P<version>\d+)$").expect("failed to compile level regex")
@@ -158,14 +157,13 @@ impl FromMeta for Level {
 
 #[cfg(test)]
 mod test {
+    #[cfg(feature = "darling")]
+    use quote::quote;
     use rstest::rstest;
     use rstest_reuse::*;
 
     use super::*;
 
-    #[cfg(feature = "darling")]
-    use quote::quote;
-
     #[cfg(feature = "darling")]
     fn parse_meta(tokens: proc_macro2::TokenStream) -> ::std::result::Result<syn::Meta, String> {
         let attribute: syn::Attribute = syn::parse_quote!(#[#tokens]);

crates/k8s-version/src/version.rs

@@ -1,10 +1,9 @@
 use std::{cmp::Ordering, fmt::Display, num::ParseIntError, str::FromStr, sync::LazyLock};
 
-use regex::Regex;
-use snafu::{OptionExt, ResultExt, Snafu};
-
 #[cfg(feature = "darling")]
 use darling::FromMeta;
+use regex::Regex;
+use snafu::{OptionExt, ResultExt, Snafu};
 
 use crate::{Level, ParseLevelError};
 
@@ -117,14 +116,13 @@ impl Version {
 
 #[cfg(test)]
 mod test {
+    #[cfg(feature = "darling")]
+    use quote::quote;
     use rstest::rstest;
     use rstest_reuse::{apply, template};
 
     use super::*;
 
-    #[cfg(feature = "darling")]
-    use quote::quote;
-
     #[cfg(feature = "darling")]
     fn parse_meta(tokens: proc_macro2::TokenStream) -> ::std::result::Result<syn::Meta, String> {
         let attribute: syn::Attribute = syn::parse_quote!(#[#tokens]);

crates/stackable-certs/src/keys/ecdsa.rs

@@ -40,12 +40,11 @@ impl SigningKey {
 }
 
 impl CertificateKeypair for SigningKey {
-    type SigningKey = p256::ecdsa::SigningKey;
+    type Error = Error;
     type Signature = ecdsa::der::Signature<NistP256>;
+    type SigningKey = p256::ecdsa::SigningKey;
     type VerifyingKey = p256::ecdsa::VerifyingKey;
 
-    type Error = Error;
-
     fn signing_key(&self) -> &Self::SigningKey {
         &self.0
     }

crates/stackable-certs/src/keys/rsa.rs

@@ -60,10 +60,10 @@ impl SigningKey {
 }
 
 impl CertificateKeypair for SigningKey {
-    type SigningKey = rsa::pkcs1v15::SigningKey<sha2::Sha256>;
+    type Error = Error;
     type Signature = rsa::pkcs1v15::Signature;
+    type SigningKey = rsa::pkcs1v15::SigningKey<sha2::Sha256>;
     type VerifyingKey = rsa::pkcs1v15::VerifyingKey<sha2::Sha256>;
-    type Error = Error;
 
     fn signing_key(&self) -> &Self::SigningKey {
         &self.0

crates/stackable-certs/src/lib.rs

@@ -21,6 +21,8 @@
 #[cfg(feature = "rustls")]
 use std::ops::Deref;
 
+use snafu::Snafu;
+use x509_cert::{spki::EncodePublicKey, Certificate};
 #[cfg(feature = "rustls")]
 use {
     p256::pkcs8::EncodePrivateKey,
@@ -29,9 +31,6 @@ use {
     x509_cert::der::Encode,
 };
 
-use snafu::Snafu;
-use x509_cert::{spki::EncodePublicKey, Certificate};
-
 use crate::keys::CertificateKeypair;
 
 pub mod ca;

crates/stackable-operator/src/builder/configmap.rs

@@ -1,6 +1,7 @@
+use std::collections::BTreeMap;
+
 use k8s_openapi::{api::core::v1::ConfigMap, apimachinery::pkg::apis::meta::v1::ObjectMeta};
 use snafu::{OptionExt, Snafu};
-use std::collections::BTreeMap;
 
 type Result<T, E = Error> = std::result::Result<T, E>;
 
@@ -64,10 +65,10 @@ impl ConfigMapBuilder {
 
 #[cfg(test)]
 mod tests {
-    use crate::builder::{configmap::ConfigMapBuilder, meta::ObjectMetaBuilder};
-
     use std::collections::BTreeMap;
 
+    use crate::builder::{configmap::ConfigMapBuilder, meta::ObjectMetaBuilder};
+
     #[test]
     fn configmap_builder() {
         let mut data = BTreeMap::new();

crates/stackable-operator/src/builder/meta.rs

@@ -311,9 +311,10 @@ impl OwnerReferenceBuilder {
 
 #[cfg(test)]
 mod tests {
+    use k8s_openapi::api::core::v1::Pod;
+
     use super::*;
     use crate::builder::meta::ObjectMetaBuilder;
-    use k8s_openapi::api::core::v1::Pod;
 
     #[test]
     fn objectmeta_builder() {