Enable additional rustc and Clippy lints

Enables some off-by-default lints that we already use in the `libcnb.rs`
repository.

https://doc.rust-lang.org/rustc/lints/listing/allowed-by-default.html#unreachable-pub
https://doc.rust-lang.org/rustc/lints/listing/allowed-by-default.html#unsafe-code
https://rust-lang.github.io/rust-clippy/master/index.html#/panic_in_result_fn
https://rust-lang.github.io/rust-clippy/master/index.html#/unwrap_used

GUS-W-14523799.

Cargo.toml

@@ -7,8 +7,12 @@ edition = "2021"
 rust-version = "1.74"
 
 [workspace.lints.rust]
+unreachable_pub = "warn"
+unsafe_code = "warn"
 unused_crate_dependencies = "warn"
 
 [workspace.lints.clippy]
+panic_in_result_fn = "warn"
 pedantic = "warn"
+unwrap_used = "warn"
 module_name_repetitions = "allow"

buildpacks/ruby/src/gem_list.rs

@@ -14,8 +14,8 @@ use std::process::Command;
 ///
 /// Requires `ruby` and `bundle` to be installed and on the PATH
 #[derive(Debug)]
-pub struct GemList {
-    pub gems: HashMap<String, GemVersion>,
+pub(crate) struct GemList {
+    pub(crate) gems: HashMap<String, GemVersion>,
 }
 
 /// Converts the output of `$ gem list` into a data structure that can be inspected and compared
@@ -59,7 +59,10 @@ impl GemList {
     /// # Errors
     ///
     /// Errors if the command `bundle list` is unsuccessful.
-    pub fn from_bundle_list<T, K, V>(envs: T, _logger: &dyn SectionLogger) -> Result<Self, CmdError>
+    pub(crate) fn from_bundle_list<T, K, V>(
+        envs: T,
+        _logger: &dyn SectionLogger,
+    ) -> Result<Self, CmdError>
     where
         T: IntoIterator<Item = (K, V)>,
         K: AsRef<OsStr>,

buildpacks/ruby/src/layers/bundle_download_layer.rs

@@ -18,7 +18,7 @@ use std::process::Command;
 
 #[derive(Deserialize, Serialize, Debug, Clone)]
 pub(crate) struct BundleDownloadLayerMetadata {
-    pub version: ResolvedBundlerVersion,
+    pub(crate) version: ResolvedBundlerVersion,
 }
 
 /// # Install the bundler gem
@@ -28,9 +28,9 @@ pub(crate) struct BundleDownloadLayerMetadata {
 /// Installs a copy of `bundler` to the `<layer-dir>` with a bundler executable in
 /// `<layer-dir>/bin`. Must run before [`crate.steps.bundle_install`].
 pub(crate) struct BundleDownloadLayer<'a> {
-    pub env: Env,
-    pub metadata: BundleDownloadLayerMetadata,
-    pub _section_logger: &'a dyn SectionLogger,
+    pub(crate) env: Env,
+    pub(crate) metadata: BundleDownloadLayerMetadata,
+    pub(crate) _section_logger: &'a dyn SectionLogger,
 }
 
 impl<'a> Layer for BundleDownloadLayer<'a> {

buildpacks/ruby/src/layers/bundle_install_layer.rs

@@ -31,17 +31,17 @@ pub(crate) const FORCE_BUNDLE_INSTALL_CACHE_KEY: &str = "v1";
 /// `BundleInstallLayer::create` are the same.
 #[derive(Debug)]
 pub(crate) struct BundleInstallLayer<'a> {
-    pub env: Env,
-    pub without: BundleWithout,
-    pub _section_log: &'a dyn SectionLogger,
-    pub metadata: BundleInstallLayerMetadata,
+    pub(crate) env: Env,
+    pub(crate) without: BundleWithout,
+    pub(crate) _section_log: &'a dyn SectionLogger,
+    pub(crate) metadata: BundleInstallLayerMetadata,
 }
 
 #[derive(Deserialize, Serialize, Debug, Clone, Eq, PartialEq)]
 pub(crate) struct BundleInstallLayerMetadata {
-    pub stack: StackId,
-    pub ruby_version: ResolvedRubyVersion,
-    pub force_bundle_install_key: String,
+    pub(crate) stack: StackId,
+    pub(crate) ruby_version: ResolvedRubyVersion,
+    pub(crate) force_bundle_install_key: String,
 
     /// A struct that holds the cryptographic hash of components that can
     /// affect the result of `bundle install`. When these values do not
@@ -54,7 +54,7 @@ pub(crate) struct BundleInstallLayerMetadata {
     /// This value is cached with metadata, so changing the struct
     /// may cause metadata to be invalidated (and the cache cleared).
     ///
-    pub digest: MetadataDigest, // Must be last for serde to be happy https://github.com/toml-rs/toml-rs/issues/142
+    pub(crate) digest: MetadataDigest, // Must be last for serde to be happy https://github.com/toml-rs/toml-rs/issues/142
 }
 
 impl<'a> BundleInstallLayer<'a> {

buildpacks/ruby/src/layers/metrics_agent_install.rs

@@ -31,7 +31,7 @@ const DOWNLOAD_SHA: &str = "f9bf9f33c949e15ffed77046ca38f8dae9307b6a0181c6af29a2
 
 #[derive(Debug)]
 pub(crate) struct MetricsAgentInstall<'a> {
-    pub _in_section: &'a dyn SectionLogger, // force the layer to be called within a Section logging context, not necessary but it's safer
+    pub(crate) _in_section: &'a dyn SectionLogger, // force the layer to be called within a Section logging context, not necessary but it's safer
 }
 
 #[derive(Deserialize, Serialize, Debug, Clone)]

buildpacks/ruby/src/layers/ruby_install_layer.rs

@@ -31,14 +31,14 @@ use url::Url;
 /// When the Ruby version changes, invalidate and re-run.
 ///
 pub(crate) struct RubyInstallLayer<'a> {
-    pub _in_section: &'a dyn SectionLogger, // force the layer to be called within a Section logging context, not necessary but it's safer
-    pub metadata: RubyInstallLayerMetadata,
+    pub(crate) _in_section: &'a dyn SectionLogger, // force the layer to be called within a Section logging context, not necessary but it's safer
+    pub(crate) metadata: RubyInstallLayerMetadata,
 }
 
 #[derive(Deserialize, Serialize, Debug, Clone)]
 pub(crate) struct RubyInstallLayerMetadata {
-    pub stack: StackId,
-    pub version: ResolvedRubyVersion,
+    pub(crate) stack: StackId,
+    pub(crate) version: ResolvedRubyVersion,
 }
 
 impl<'a> Layer for RubyInstallLayer<'a> {

buildpacks/ruby/src/main.rs

@@ -35,7 +35,7 @@ use libcnb_test as _;
 
 use clap as _;
 
-pub(crate) struct RubyBuildpack;
+struct RubyBuildpack;
 
 impl Buildpack for RubyBuildpack {
     type Platform = GenericPlatform;
@@ -238,7 +238,7 @@ fn needs_java(gemfile_lock: &str) -> bool {
 }
 
 #[derive(Debug)]
-pub(crate) enum RubyBuildpackError {
+enum RubyBuildpackError {
     RakeDetectError(CmdError),
     GemListGetError(CmdError),
     RubyInstallError(RubyInstallError),
@@ -260,7 +260,7 @@ impl From<RubyBuildpackError> for libcnb::Error<RubyBuildpackError> {
 buildpack_main!(RubyBuildpack);
 
 #[derive(serde::Deserialize, serde::Serialize, Debug, Clone, PartialEq, Eq)]
-pub(crate) struct BundleWithout(String);
+struct BundleWithout(String);
 
 impl BundleWithout {
     fn new(without: impl AsRef<str>) -> Self {

buildpacks/ruby/src/rake_status.rs

@@ -2,7 +2,7 @@ use crate::gem_list::GemList;
 use std::path::{Path, PathBuf};
 
 /// Determine if an application is ready to run a rake task or not
-pub fn check_rake_ready(
+pub(crate) fn check_rake_ready(
     app_path: &Path,
     gem_list: &GemList,
     globs: impl IntoIterator<Item = impl AsRef<str>>,
@@ -15,7 +15,7 @@ pub fn check_rake_ready(
 }
 
 #[derive(Debug, Eq, PartialEq)]
-pub enum RakeStatus {
+pub(crate) enum RakeStatus {
     Ready(PathBuf),
     MissingRakeGem,
     MissingRakefile,

buildpacks/ruby/src/rake_task_detect.rs

@@ -17,15 +17,19 @@ use std::{ffi::OsStr, process::Command};
 /// assert!(!rake_detect.has_task("assets:precompile"));
 /// ```
 #[derive(Default)]
-pub struct RakeDetect {
+pub(crate) struct RakeDetect {
     output: String,
 }
 
 impl RakeDetect {
     /// # Errors
     ///
     /// Will return `Err` if `bundle exec rake -p` command cannot be invoked by the operating system.
-    pub fn from_rake_command<T: IntoIterator<Item = (K, V)>, K: AsRef<OsStr>, V: AsRef<OsStr>>(
+    pub(crate) fn from_rake_command<
+        T: IntoIterator<Item = (K, V)>,
+        K: AsRef<OsStr>,
+        V: AsRef<OsStr>,
+    >(
         _logger: &dyn SectionLogger,
         envs: T,
         error_on_failure: bool,
@@ -53,7 +57,7 @@ impl RakeDetect {
     }
 
     #[must_use]
-    pub fn has_task(&self, string: &str) -> bool {
+    pub(crate) fn has_task(&self, string: &str) -> bool {
         let task_re = regex::Regex::new(&format!("\\s{string}")).expect("clippy");
         task_re.is_match(&self.output)
     }

buildpacks/ruby/tests/integration_test.rs

@@ -1,5 +1,7 @@
 // Required due to: https://github.com/rust-lang/rust/issues/95513
 #![allow(unused_crate_dependencies)]
+// Required due to: https://github.com/rust-lang/rust-clippy/issues/11119
+#![allow(clippy::unwrap_used)]
 
 use libcnb_test::{
     assert_contains, assert_empty, BuildConfig, BuildpackReference, ContainerConfig,

clippy.toml

@@ -0,0 +1 @@
+allow-unwrap-in-tests = true

commons/bin/print_style_guide.rs

@@ -63,6 +63,8 @@ fn main() {
         .step("Output can be streamed. Mostly from commands. Example:")
         .step_timed_stream(&format!("Running {}", fmt::command(command.name())));
 
+        // TODO: Remove usage of unwrap(): https://github.com/heroku/buildpacks-ruby/issues/238
+        #[allow(clippy::unwrap_used)]
         command.stream_output(stream.io(), stream.io()).unwrap();
         log = stream.finish_timed_stream().end_section();
         drop(log);
@@ -100,6 +102,8 @@ fn main() {
             // do work here
         });
         log_step_stream("log_step_stream()", |stream| {
+            // TODO: Remove usage of unwrap(): https://github.com/heroku/buildpacks-ruby/issues/238
+            #[allow(clippy::unwrap_used)]
             Command::new("bash")
                 .args(["-c", "ps aux | grep cargo"])
                 .stream_output(stream.io(), stream.io())
@@ -113,6 +117,8 @@ fn main() {
     }
 
     {
+        // TODO: Remove usage of unwrap(): https://github.com/heroku/buildpacks-ruby/issues/238
+        #[allow(clippy::unwrap_used)]
         let cmd_error = Command::new("iDoNotExist").named_output().err().unwrap();
 
         let mut log = BuildLog::new(stdout()).buildpack_name("Error and warnings");

commons/src/cache/clean.rs

@@ -128,7 +128,7 @@ mod tests {
     use super::*;
 
     #[test]
-    pub fn test_grabs_files() {
+    fn test_grabs_files() {
         // FWIW This action must be done on two lines as the tmpdir gets cleaned
         // as soon as the variable goes out of scope and a path
         // reference does not retain it's caller
@@ -146,7 +146,7 @@ mod tests {
 
     use byte_unit::n_mib_bytes;
 
-    pub fn touch_file(path: &PathBuf, f: impl FnOnce(&PathBuf)) {
+    fn touch_file(path: &PathBuf, f: impl FnOnce(&PathBuf)) {
         if let Some(parent) = path.parent() {
             if !parent.exists() {
                 fs_err::create_dir_all(parent).unwrap();

commons/src/cache/in_app_dir_cache_layer.rs

@@ -23,7 +23,7 @@ use std::path::PathBuf;
 ///  asset.
 #[derive(Deserialize, Serialize, Debug, Clone)]
 pub(crate) struct InAppDirCacheLayer<B> {
-    pub app_dir_path: PathBuf,
+    pub(crate) app_dir_path: PathBuf,
     buildpack: PhantomData<B>,
 }
 
@@ -33,7 +33,7 @@ pub(crate) struct InAppDirCacheLayerMetadata {
 }
 
 impl<B> InAppDirCacheLayer<B> {
-    pub fn new(app_dir_path: PathBuf) -> Self {
+    pub(crate) fn new(app_dir_path: PathBuf) -> Self {
         Self {
             app_dir_path,
             buildpack: PhantomData,

commons/src/output/background_timer.rs

@@ -37,6 +37,8 @@ where
 
     let arc_io = arc_io.clone();
     let handle = std::thread::spawn(move || {
+        // TODO: Remove usage of unwrap(): https://github.com/heroku/buildpacks-ruby/issues/238
+        #[allow(clippy::unwrap_used)]
         let mut io = arc_io.lock().unwrap();
         write!(&mut io, "{start}").expect("Internal error");
         io.flush().expect("Internal error");

commons/src/output/util.rs

@@ -116,7 +116,7 @@ pub(crate) struct LinesWithEndings<'a> {
 }
 
 impl<'a> LinesWithEndings<'a> {
-    pub fn from(input: &'a str) -> LinesWithEndings<'a> {
+    pub(crate) fn from(input: &'a str) -> LinesWithEndings<'a> {
         LinesWithEndings { input }
     }
 }