fix clippy pedantry warnings

src/cli.rs

@@ -1,7 +1,7 @@
 use clap::{Parser, Subcommand};
 use std::{path::PathBuf, str::FromStr};
 
-/// VM controller for AirgapOS
+/// VM controller for `AirgapOS`
 #[derive(Parser, Clone, Debug)]
 pub struct App {
     // global options go here

src/main.rs

@@ -1,3 +1,5 @@
+#![allow(clippy::redundant_else)]
+
 use clap::Parser;
 use eyre::WrapErr;
 use std::io::Write;
@@ -60,13 +62,16 @@ fn main() -> eyre::Result<()> {
             let spawn_arguments = SpawnArguments::default();
             let mut vm = VirtualMachine::load(spawn_arguments, None)?;
             vm.execute_host("qmp_capabilities", serde_json::json!({}))?;
-            vm.execute_host("device_add", serde_json::json!({
+            vm.execute_host(
+                "device_add",
+                serde_json::json!({
                     "driver": "usb-host",
                     "bus": "usb.0",
                     "vendorid": device.vendor_id,
                     "productid": device.device_id,
-            }))?;
+                }),
-        },
+            )?;
+        }
         cli::Commands::Push {
             local_path,
             remote_path,
@@ -88,7 +93,9 @@ fn main() -> eyre::Result<()> {
             let mut vm = VirtualMachine::load(spawn_arguments, None)?;
             let (response, exit_code) = vm.run_command(&command, args)?;
             std::io::stdout().write_all(&response)?;
-            std::process::exit(exit_code as i32);
+            std::process::exit(
+                i32::try_from(exit_code).context(eyre::eyre!("bad PID: pid < i32::MAX << 1"))?,
+            );
         }
     }
 

src/vm.rs

@@ -66,6 +66,7 @@ fn to_lowercase_hexlike(s: impl AsRef<str>) -> String {
     s.to_ascii_lowercase()
 }
 
+#[allow(clippy::struct_field_names)]
 #[derive(Clone, Debug)]
 struct Device {
     vendor_id: u16,
@@ -100,7 +101,7 @@ fn find_pci_device_by_class(class: u16) -> Result<Vec<Device>> {
             let bus_id = bus_address
                 .into_string()
                 .map_err(|bad| eyre::eyre!("non-utf8 bus address: {bad:?}"))?
-                .split_once(":")
+                .split_once(':')
                 .ok_or(eyre::eyre!("bad path ID"))?
                 .1
                 .to_string();
@@ -169,8 +170,9 @@ impl VirtualMachine {
         if std::fs::exists(&args.lockfile_path)? {
             // Check if VM is running
             use nix::unistd::{getpgid, Pid};
-            let pid = get_pid(&args.lockfile_path)?;
+            let pid = i32::try_from(get_pid(&args.lockfile_path)?)
-            if getpgid(Some(Pid::from_raw(pid as i32))).is_ok() {
+                .context(eyre::eyre!("bad PID: pid < i32::MAX << 1"))?;
+            if getpgid(Some(Pid::from_raw(pid))).is_ok() {
                 // process exists, exit
                 return Err(eyre::eyre!(
                     "VM with this configuration exists as PID {pid}"
@@ -217,7 +219,7 @@ impl VirtualMachine {
                 ),
             )?;
             net_args.push("-device".to_string());
-            net_args.push(format!("vfio-pci,host={bus_id}"))
+            net_args.push(format!("vfio-pci,host={bus_id}"));
         }
 
         let mut child = Command::new("qemu-system-x86_64")
@@ -274,13 +276,12 @@ impl VirtualMachine {
 
     pub fn load(args: SpawnArguments, pid: Option<u32>) -> Result<Self> {
         let bar = spinner("Connecting to VM");
-        let pid = match pid {
+        let pid = if let Some(pid) = pid {
-            Some(pid) => pid,
+            pid
-            None => {
+        } else {
             let pid_str = std::fs::read_to_string(&args.lockfile_path)
                 .context("error reading PID from lockfile")?;
             pid_str.parse().context("could not parse PID")?
-            }
         };
 
         let guest = UnixStream::connect(&args.guest_agent_socket_path)
@@ -319,7 +320,8 @@ impl VirtualMachine {
         );
 
         let mut server_hello = String::new();
-        host_reader.read_line(&mut server_hello)
+        host_reader
+            .read_line(&mut server_hello)
             .context("can't read line from socket (pre-load)")?;
 
         let mut vm = Self {
@@ -339,7 +341,7 @@ impl VirtualMachine {
         // crashing if those circumstances happen to be met.
         let time = SystemTime::now().duration_since(UNIX_EPOCH)?;
 
-        let identifier = time.as_secs() % (u32::MAX as u64);
+        let identifier = time.as_secs() % u64::from(u32::MAX);
 
         let ping_response = vm
             .execute_internal("guest-sync", serde_json::json!({"id": identifier}))
@@ -441,7 +443,8 @@ impl VirtualMachine {
                     .ok_or(eyre::eyre!("not given 'count' of bytes written"))?
                     .as_u64()
                     .ok_or(eyre::eyre!("'count' not u64"))?;
-                written += response_written as usize;
+                written +=
+                    usize::try_from(response_written).expect("wrote more than u46::MAX bytes");
                 if written == size {
                     break;
                 }
@@ -672,7 +675,8 @@ impl VirtualMachine {
             .read_line(&mut line)
             .context("can't read line from socket")?;
 
-        let response: serde_json::Value = serde_json::from_str(&line).context("response from qemu is not json")?;
+        let response: serde_json::Value =
+            serde_json::from_str(&line).context("response from qemu is not json")?;
 
         bar.finish_and_clear();
 
@@ -694,7 +698,9 @@ impl VirtualMachine {
             sys::signal::{kill, SIGKILL},
             unistd::{getpgid, Pid},
         };
-        let pid = Pid::from_raw(self.pid as i32);
+        let pid = Pid::from_raw(
+            i32::try_from(self.pid).context(eyre::eyre!("bad PID: pid < i32::MAX << 1"))?,
+        );
         if getpgid(Some(pid)).is_err() {
             eprintln!("Process not found");
             return Ok(());