Reduce cognitive complexity: just move some of the contents in functions

src/uu/fmt/src/fmt.rs

@@ -11,7 +11,7 @@ use clap::{crate_version, Arg, ArgAction, Command};
 use std::cmp;
 use std::fs::File;
 use std::io::{stdin, stdout, Write};
-use std::io::{BufReader, BufWriter, Read};
+use std::io::{BufReader, BufWriter, Read, Stdout};
 use uucore::display::Quotable;
 use uucore::error::{FromIo, UResult, USimpleError};
 use uucore::{format_usage, help_about, help_usage, show_warning};
@@ -60,10 +60,16 @@ pub struct FmtOptions {
  goal: usize,
  tabwidth: usize,
 }
-
-#[uucore::main]
-#[allow(clippy::cognitive_complexity)]
-pub fn uumain(args: impl uucore::Args) -> UResult<()> {
+/// Parse the command line arguments and return the list of files and formatting options.
+///
+/// # Arguments
+///
+/// * `args` - Command line arguments.
+///
+/// # Returns
+///
+/// A tuple containing a vector of file names and a `FmtOptions` struct.
+fn parse_arguments(args: impl uucore::Args) -> UResult<(Vec<String>, FmtOptions)> {
  let matches = uu_app().try_get_matches_from(args)?;
 
  let mut files: Vec<String> = matches
@@ -177,39 +183,68 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
  files.push("-".to_owned());
  }
 
- let mut ostream = BufWriter::new(stdout());
+ Ok((files, fmt_opts))
+}
 
- for i in files.iter().map(|x| &x[..]) {
- let mut fp = match i {
- "-" => BufReader::new(Box::new(stdin()) as Box<dyn Read + 'static>),
- _ => match File::open(i) {
- Ok(f) => BufReader::new(Box::new(f) as Box<dyn Read + 'static>),
- Err(e) => {
- show_warning!("{}: {}", i.maybe_quote(), e);
- continue;
- }
- },
- };
- let p_stream = ParagraphStream::new(&fmt_opts, &mut fp);
- for para_result in p_stream {
- match para_result {
- Err(s) => {
- ostream
- .write_all(s.as_bytes())
- .map_err_context(|| "failed to write output".to_string())?;
- ostream
- .write_all(b"\n")
- .map_err_context(|| "failed to write output".to_string())?;
- }
- Ok(para) => break_lines(&para, &fmt_opts, &mut ostream)
- .map_err_context(|| "failed to write output".to_string())?,
+/// Process the content of a file and format it according to the provided options.
+///
+/// # Arguments
+///
+/// * `file_name` - The name of the file to process. A value of "-" represents the standard input.
+/// * `fmt_opts` - A reference to a `FmtOptions` struct containing the formatting options.
+/// * `ostream` - A mutable reference to a `BufWriter` wrapping the standard output.
+///
+/// # Returns
+///
+/// A `UResult<()>` indicating success or failure.
+fn process_file(
+ file_name: &str,
+ fmt_opts: &FmtOptions,
+ ostream: &mut BufWriter<Stdout>,
+) -> UResult<()> {
+ let mut fp = match file_name {
+ "-" => BufReader::new(Box::new(stdin()) as Box<dyn Read + 'static>),
+ _ => match File::open(file_name) {
+ Ok(f) => BufReader::new(Box::new(f) as Box<dyn Read + 'static>),
+ Err(e) => {
+ show_warning!("{}: {}", file_name.maybe_quote(), e);
+ return Ok(());
+ }
+ },
+ };
+
+ let p_stream = ParagraphStream::new(fmt_opts, &mut fp);
+ for para_result in p_stream {
+ match para_result {
+ Err(s) => {
+ ostream
+ .write_all(s.as_bytes())
+ .map_err_context(|| "failed to write output".to_string())?;
+ ostream
+ .write_all(b"\n")
+ .map_err_context(|| "failed to write output".to_string())?;
  }
+ Ok(para) => break_lines(&para, fmt_opts, ostream)
+ .map_err_context(|| "failed to write output".to_string())?,
  }
+ }
+
+ // flush the output after each file
+ ostream
+ .flush()
+ .map_err_context(|| "failed to write output".to_string())?;
+
+ Ok(())
+}
+
+#[uucore::main]
+pub fn uumain(args: impl uucore::Args) -> UResult<()> {
+ let (files, fmt_opts) = parse_arguments(args)?;
+
+ let mut ostream = BufWriter::new(stdout());
 
- // flush the output after each file
- ostream
- .flush()
- .map_err_context(|| "failed to write output".to_string())?;
+ for file_name in &files {
+ process_file(file_name, &fmt_opts, &mut ostream)?;
  }
 
  Ok(())