refactor(cli+core): various cleanups in Rust (#8336)

8 files changed, 52 insertions, 85 deletions

diff --git a/cli/bench/main.rs b/cli/bench/main.rs
index 0b8f9aa7b..de19ceda8 100644
--- a/cli/bench/main.rs
+++ b/cli/bench/main.rs
@@ -183,10 +183,10 @@ fn get_binary_sizes(target_dir: &PathBuf) -> Result<Value> {
   // Because cargo's OUT_DIR is not predictable, search the build tree for
   // snapshot related files.
   for file in walkdir::WalkDir::new(target_dir) {
-    if file.is_err() {
-      continue;
-    }
-    let file = file.unwrap();
+    let file = match file {
+      Ok(file) => file,
+      Err(_) => continue,
+    };
     let filename = file.file_name().to_str().unwrap().to_string();
 
     if !BINARY_TARGET_FILES.contains(&filename.as_str()) {
diff --git a/cli/diff.rs b/cli/diff.rs
index c8a86736d..5ba55e1ca 100644
--- a/cli/diff.rs
+++ b/cli/diff.rs
@@ -2,8 +2,6 @@
 
 use crate::colors;
 use dissimilar::{diff as difference, Chunk};
-use std::fmt;
-use std::fmt::Write;
 
 fn fmt_add() -> String {
   colors::green_bold("+").to_string()
@@ -36,33 +34,31 @@ fn write_line_diff(
   line_number_width: usize,
   orig: &mut String,
   edit: &mut String,
-) -> fmt::Result {
+) {
   let split = orig.split('\n').enumerate();
   for (i, s) in split {
-    write!(
-      diff,
+    diff.push_str(&format!(
       "{:width$}{} ",
       *orig_line + i,
       colors::gray(" |"),
       width = line_number_width
-    )?;
-    write!(diff, "{}", fmt_rem())?;
-    write!(diff, "{}", s)?;
-    writeln!(diff)?;
+    ));
+    diff.push_str(&fmt_rem());
+    diff.push_str(s);
+    diff.push('\n');
   }
 
   let split = edit.split('\n').enumerate();
   for (i, s) in split {
-    write!(
-      diff,
+    diff.push_str(&format!(
       "{:width$}{} ",
       *edit_line + i,
       colors::gray(" |"),
       width = line_number_width
-    )?;
-    write!(diff, "{}", fmt_add())?;
-    write!(diff, "{}", s)?;
-    writeln!(diff)?;
+    ));
+    diff.push_str(&fmt_add());
+    diff.push_str(s);
+    diff.push('\n');
   }
 
   *orig_line += orig.split('\n').count();
@@ -70,14 +66,12 @@ fn write_line_diff(
 
   orig.clear();
   edit.clear();
-
-  Ok(())
 }
 
 /// Print diff of the same file_path, before and after formatting.
 ///
 /// Diff format is loosely based on Github diff formatting.
-pub fn diff(orig_text: &str, edit_text: &str) -> Result<String, fmt::Error> {
+pub fn diff(orig_text: &str, edit_text: &str) -> String {
   let lines = edit_text.split('\n').count();
   let line_number_width = lines.to_string().chars().count();
 
@@ -87,10 +81,10 @@ pub fn diff(orig_text: &str, edit_text: &str) -> Result<String, fmt::Error> {
   let mut text2 = edit_text.to_string();
 
   if !text1.ends_with('\n') {
-    writeln!(text1)?;
+    text1.push('\n');
   }
   if !text2.ends_with('\n') {
-    writeln!(text2)?;
+    text2.push('\n');
   }
 
   let mut orig_line: usize = 1;
@@ -134,7 +128,7 @@ pub fn diff(orig_text: &str, edit_text: &str) -> Result<String, fmt::Error> {
                 line_number_width,
                 &mut orig,
                 &mut edit,
-              )?;
+              );
               changes = false
             } else {
               orig.clear();
@@ -149,7 +143,7 @@ pub fn diff(orig_text: &str, edit_text: &str) -> Result<String, fmt::Error> {
       }
     }
   }
-  Ok(diff)
+  diff
 }
 
 #[test]
@@ -157,16 +151,17 @@ fn test_diff() {
   let simple_console_log_unfmt = "console.log('Hello World')";
   let simple_console_log_fmt = "console.log(\"Hello World\");";
   assert_eq!(
-    colors::strip_ansi_codes(
-      &diff(simple_console_log_unfmt, simple_console_log_fmt).unwrap()
-    ),
+    colors::strip_ansi_codes(&diff(
+      simple_console_log_unfmt,
+      simple_console_log_fmt
+    )),
     "1 | -console.log('Hello World')\n1 | +console.log(\"Hello World\");\n"
   );
 
   let line_number_unfmt = "\n\n\n\nconsole.log(\n'Hello World'\n)";
   let line_number_fmt = "console.log(\n\"Hello World\"\n);";
   assert_eq!(
-    colors::strip_ansi_codes(&diff(line_number_unfmt, line_number_fmt).unwrap()),
+    colors::strip_ansi_codes(&diff(line_number_unfmt, line_number_fmt)),
     "1 | -\n2 | -\n3 | -\n4 | -\n5 | -console.log(\n1 | +console.log(\n6 | -'Hello World'\n2 | +\"Hello World\"\n7 | -)\n3 | +);\n"
   )
 }
diff --git a/cli/file_fetcher.rs b/cli/file_fetcher.rs
index 933cbf203..50544bfd9 100644
--- a/cli/file_fetcher.rs
+++ b/cli/file_fetcher.rs
@@ -55,11 +55,7 @@ struct FileCache(Arc<Mutex<HashMap<ModuleSpecifier, File>>>);
 impl FileCache {
   pub fn get(&self, specifier: &ModuleSpecifier) -> Option<File> {
     let cache = self.0.lock().unwrap();
-    if let Some(file) = cache.get(specifier) {
-      Some(file.clone())
-    } else {
-      None
-    }
+    cache.get(specifier).cloned()
   }
 
   pub fn insert(&self, specifier: ModuleSpecifier, file: File) -> Option<File> {
@@ -259,18 +255,16 @@ fn map_js_like_extension(
 }
 
 /// Remove shebangs from the start of source code strings
-fn strip_shebang(value: String) -> String {
+fn strip_shebang(mut value: String) -> String {
   if value.starts_with("#!") {
-    let value = if let Some(mid) = value.find('\n') {
+    if let Some(mid) = value.find('\n') {
       let (_, rest) = value.split_at(mid);
-      rest.to_string()
+      value = rest.to_string()
     } else {
-      "".to_string()
-    };
-    value
-  } else {
-    value
+      value.clear()
+    }
   }
+  value
 }
 
 /// A structure for resolving, fetching and caching source files.
diff --git a/cli/flags.rs b/cli/flags.rs
index b0f098ecf..7c38a25d8 100644
--- a/cli/flags.rs
+++ b/cli/flags.rs
@@ -9,6 +9,7 @@ use clap::SubCommand;
 use log::Level;
 use std::net::SocketAddr;
 use std::path::PathBuf;
+use std::str::FromStr;
 
 /// Creates vector of strings, Vec<String>
 macro_rules! svec {
@@ -425,7 +426,6 @@ fn bundle_parse(flags: &mut Flags, matches: &clap::ArgMatches) {
 fn completions_parse(flags: &mut Flags, matches: &clap::ArgMatches) {
   let shell: &str = matches.value_of("shell").unwrap();
   let mut buf: Vec<u8> = vec![];
-  use std::str::FromStr;
   clap_root().gen_completions_to(
     "deno",
     clap::Shell::from_str(shell).unwrap(),
@@ -1324,7 +1324,7 @@ fn reload_arg<'a, 'b>() -> Arg<'a, 'b> {
 fn reload_arg_parse(flags: &mut Flags, matches: &ArgMatches) {
   if let Some(cache_bl) = matches.values_of("reload") {
     let raw_cache_blocklist: Vec<String> =
-      cache_bl.map(std::string::ToString::to_string).collect();
+      cache_bl.map(ToString::to_string).collect();
     if raw_cache_blocklist.is_empty() {
       flags.reload = true;
     } else {
@@ -1475,7 +1475,7 @@ fn permission_args_parse(flags: &mut Flags, matches: &clap::ArgMatches) {
 
   if let Some(net_wl) = matches.values_of("allow-net") {
     let raw_net_allowlist: Vec<String> =
-      net_wl.map(std::string::ToString::to_string).collect();
+      net_wl.map(ToString::to_string).collect();
     if raw_net_allowlist.is_empty() {
       flags.allow_net = true;
     } else {
@@ -1515,18 +1515,16 @@ pub fn resolve_urls(urls: Vec<String>) -> Vec<String> {
   use deno_core::url::Url;
   let mut out: Vec<String> = vec![];
   for urlstr in urls.iter() {
-    use std::str::FromStr;
-    let result = Url::from_str(urlstr);
-    if result.is_err() {
+    if let Ok(mut url) = Url::from_str(urlstr) {
+      url.set_fragment(None);
+      let mut full_url = String::from(url.as_str());
+      if full_url.len() > 1 && full_url.ends_with('/') {
+        full_url.pop();
+      }
+      out.push(full_url);
+    } else {
       panic!("Bad Url: {}", urlstr);
     }
-    let mut url = result.unwrap();
-    url.set_fragment(None);
-    let mut full_url = String::from(url.as_str());
-    if full_url.len() > 1 && full_url.ends_with('/') {
-      full_url.pop();
-    }
-    out.push(full_url);
   }
   out
 }
diff --git a/cli/fmt.rs b/cli/fmt.rs
index 8f1350973..4b51e038e 100644
--- a/cli/fmt.rs
+++ b/cli/fmt.rs
@@ -71,24 +71,10 @@ async fn check_source_files(
           if formatted_text != file_text {
             not_formatted_files_count.fetch_add(1, Ordering::Relaxed);
             let _g = output_lock.lock().unwrap();
-            match diff(&file_text, &formatted_text) {
-              Ok(diff) => {
-                info!("");
-                info!(
-                  "{} {}:",
-                  colors::bold("from"),
-                  file_path.display().to_string()
-                );
-                info!("{}", diff);
-              }
-              Err(e) => {
-                eprintln!(
-                  "Error generating diff: {}",
-                  file_path.to_string_lossy()
-                );
-                eprintln!("   {}", e);
-              }
-            }
+            let diff = diff(&file_text, &formatted_text);
+            info!("");
+            info!("{} {}:", colors::bold("from"), file_path.display());
+            info!("{}", diff);
           }
         }
         Err(e) => {
diff --git a/core/runtime.rs b/core/runtime.rs
index e6e69636f..e915571e0 100644
--- a/core/runtime.rs
+++ b/core/runtime.rs
@@ -1586,8 +1586,7 @@ pub mod tests {
         assert_eq!(bufs.len(), 1);
         assert_eq!(bufs[0].len(), 1);
         assert_eq!(bufs[0][0], 42);
-        let mut vec = Vec::<u8>::new();
-        vec.resize(100 * 1024 * 1024, 0);
+        let mut vec = vec![0u8; 100 * 1024 * 1024];
         vec[0] = 99;
         let buf = vec.into_boxed_slice();
         Op::Sync(buf)
@@ -1602,8 +1601,7 @@ pub mod tests {
         assert_eq!(bufs.len(), 1);
         assert_eq!(bufs[0].len(), 1);
         assert_eq!(bufs[0][0], 42);
-        let mut vec = Vec::<u8>::new();
-        vec.resize(100 * 1024 * 1024, 0);
+        let mut vec = vec![0u8; 100 * 1024 * 1024];
         vec[0] = 4;
         let buf = vec.into_boxed_slice();
         Op::Async(futures::future::ready(buf).boxed())
diff --git a/core/shared_queue.rs b/core/shared_queue.rs
index e8ac30ebc..715fb4395 100644
--- a/core/shared_queue.rs
+++ b/core/shared_queue.rs
@@ -42,9 +42,7 @@ pub struct SharedQueue {
 
 impl SharedQueue {
   pub fn new(len: usize) -> Self {
-    let mut buf = Vec::new();
-    buf.resize(HEAD_INIT + len, 0);
-    let buf = buf.into_boxed_slice();
+    let buf = vec![0; HEAD_INIT + len].into_boxed_slice();
     let buf = v8::SharedArrayBuffer::new_backing_store_from_boxed_slice(buf);
     let mut q = Self {
       buf: buf.make_shared(),
@@ -263,9 +261,7 @@ mod tests {
   }
 
   fn alloc_buf(byte_length: usize) -> Box<[u8]> {
-    let mut v = Vec::new();
-    v.resize(byte_length, 0);
-    v.into_boxed_slice()
+    vec![0; byte_length].into_boxed_slice()
   }
 
   #[test]
diff --git a/test_util/src/lib.rs b/test_util/src/lib.rs
index 97a2ed334..870fbfb29 100644
--- a/test_util/src/lib.rs
+++ b/test_util/src/lib.rs
@@ -286,7 +286,7 @@ pub async fn run_all_servers() {
       Box::new(res)
     });
   let bad_redirect = warp::path("bad_redirect").map(|| -> Box<dyn Reply> {
-    let mut res = Response::new(Body::from(""));
+    let mut res = Response::new(Body::empty());
     *res.status_mut() = StatusCode::FOUND;
     Box::new(res)
   });