Fix clippy lints

Author: Heliozoa

crates/plugins/java/src/lib.rs

@@ -138,7 +138,7 @@ fn instantiate_jvm() -> Result<JvmWrapper, JavaError> {
     let tmc_dir = tmc_dir()?;
 
     // j4rs may panic
-    let jvm = match std::panic::catch_unwind(|| -> Result<Jvm, JavaError> {
+    let catch = std::panic::catch_unwind(|| -> Result<Jvm, JavaError> {
         let jvm = JvmBuilder::new()
             .with_base_path(
                 tmc_dir
@@ -152,7 +152,8 @@ fn instantiate_jvm() -> Result<JvmWrapper, JavaError> {
             .build()
             .map_err(JavaError::j4rs)?;
         Ok(jvm)
-    }) {
+    });
+    let jvm = match catch {
         Ok(jvm_result) => jvm_result?,
         Err(jvm_panic) => {
             // try to extract error message from panic, if any

crates/plugins/r/src/r_run_result.rs

@@ -1,7 +1,7 @@
 //! Struct modeling the test run results from R.
 
 use serde::{Deserialize, Serialize};
-use std::collections::HashMap;
+use std::{collections::HashMap, fmt::Write};
 use tmc_langs_framework::{RunResult, RunStatus, TestResult};
 
 #[derive(Debug, Deserialize, Serialize)]
@@ -21,8 +21,10 @@ impl From<RRunResult> for RunResult {
                 r_run_result
                     .backtrace
                     .into_iter()
-                    .map(|s| format!("{s}\n"))
-                    .collect(),
+                    .fold(String::new(), |mut output, s| {
+                        let _ = writeln!(output, "{s}");
+                        output
+                    }),
             );
         }
         let status = match r_run_result.run_status {

crates/tmc-langs-cli/src/main.rs

@@ -22,7 +22,7 @@ fn main() -> ExitCode {
             "TRACE" => "TRACE,reqwest=DEBUG,rustls=DEBUG",
             other => other,
         };
-        let _ = std::env::set_var("RUST_LOG", level);
+        std::env::set_var("RUST_LOG", level);
     }
 
     env_logger::init();
@@ -56,10 +56,11 @@ fn run() -> Result<(), ()> {
         }
     };
     let pretty = cli.pretty;
-    match std::panic::catch_unwind(|| {
+    let catch = std::panic::catch_unwind(|| {
         register_reporters(pretty);
         tmc_langs_cli::run(cli)
-    }) {
+    });
+    match catch {
         Ok(Ok(output)) => {
             print_output(&output, pretty, None).map_err(|_| ())?;
             Ok(())

crates/tmc-testmycode-client/src/client/api_v8.rs

@@ -13,7 +13,6 @@ use serde::de::DeserializeOwned;
 use std::{
     collections::HashMap,
     io::{Read, Write},
-    time::SystemTime,
 };
 use tmc_langs_plugins::Language;
 use tmc_langs_util::deserialize;