mirror of
https://github.com/RGBCube/uutils-coreutils
synced 2025-07-28 19:47:45 +00:00
fold: improve newline handling and test coverage
- refactor implementation for readability - correct handling of files with no trailing newline and/or blank lines
This commit is contained in:
Daniel Rocco
parent
20d071a482
commit
bad1df9c1b
2 changed files with 433 additions and 107 deletions
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@ -79,7 +79,6 @@ fn handle_obsolete(args: &[String]) -> (Vec<String>, Option<String>) {
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(args.to_vec(), None)
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}
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#[inline]
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fn fold(filenames: Vec<String>, bytes: bool, spaces: bool, width: usize) {
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for filename in &filenames {
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let filename: &str = &filename;
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@ -92,20 +91,40 @@ fn fold(filenames: Vec<String>, bytes: bool, spaces: bool, width: usize) {
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file_buf = safe_unwrap!(File::open(Path::new(filename)));
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&mut file_buf as &mut dyn Read
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});
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fold_file(buffer, bytes, spaces, width);
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if bytes {
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fold_file_bytewise(buffer, spaces, width);
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} else {
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fold_file(buffer, spaces, width);
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}
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}
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}
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#[inline]
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fn fold_file<T: Read>(file: BufReader<T>, bytes: bool, spaces: bool, width: usize) {
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for line_result in file.lines() {
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let mut line = safe_unwrap!(line_result);
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/// Fold `file` to fit `width` (number of columns), counting all characters as
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/// one column.
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///
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/// This function handles folding for the `-b`/`--bytes` option, counting
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/// tab, backspace, and carriage return as occupying one column, identically
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/// to all other characters in the stream.
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///
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/// If `spaces` is `true`, attempt to break lines at whitespace boundaries.
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fn fold_file_bytewise<T: Read>(mut file: BufReader<T>, spaces: bool, width: usize) {
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let mut line = String::new();
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if line.is_empty() {
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loop {
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if let Ok(0) = file.read_line(&mut line) {
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break;
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}
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if line == "\n" {
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println!();
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} else if bytes {
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line.truncate(0);
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continue;
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}
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let len = line.len();
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let mut i = 0;
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while i < len {
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let width = if len - i >= width { width } else { len - i };
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let slice = {
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@ -119,96 +138,126 @@ fn fold_file<T: Read>(file: BufReader<T>, bytes: bool, spaces: bool, width: usiz
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slice
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}
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};
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print!("{}", slice);
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// Don't duplicate trailing newlines: if the slice is "\n", the
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// previous iteration folded just before the end of the line and
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// has already printed this newline.
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if slice == "\n" {
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break;
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}
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i += slice.len();
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}
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let at_eol = i >= len;
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if at_eol {
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print!("{}", slice);
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} else {
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let mut len = line.chars().count();
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let newline = line.ends_with('\n');
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if newline {
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if len == 1 {
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println!();
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continue;
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println!("{}", slice);
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}
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len -= 1;
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line.truncate(len);
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}
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line.truncate(0);
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}
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}
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/// Fold `file` to fit `width` (number of columns).
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///
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/// By default `fold` treats tab, backspace, and carriage return specially:
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/// tab characters count as 8 columns, backspace decreases the
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/// column count, and carriage return resets the column count to 0.
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///
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/// If `spaces` is `true`, attempt to break lines at whitespace boundaries.
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#[allow(unused_assignments)]
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fn fold_file<T: Read>(mut file: BufReader<T>, spaces: bool, width: usize) {
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let mut line = String::new();
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let mut output = String::new();
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let mut count = 0;
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for (i, ch) in line.chars().enumerate() {
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if count >= width {
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let (val, ncount) = {
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let slice = &output[..];
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let (out, val, ncount) = if spaces && i + 1 < len {
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match rfind_whitespace(slice) {
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Some(m) => {
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let routput = &slice[m + 1..slice.chars().count()];
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let ncount = routput.chars().fold(0, |out, ch: char| {
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out + match ch {
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'\t' => 8,
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'\x08' => {
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if out > 0 {
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!0
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} else {
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0
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}
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}
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'\r' => return 0,
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_ => 1,
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}
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});
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(&slice[0..=m], routput, ncount)
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}
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None => (slice, "", 0),
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}
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} else {
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(slice, "", 0)
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let mut col_count = 0;
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let mut char_count = 0;
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let mut last_space = None;
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/// Print the output line, resetting the column and character counts.
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///
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/// If `spaces` is `true`, print the output line up to the last
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/// encountered whitespace character (inclusive) and set the remaining
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/// characters as the start of the next line.
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macro_rules! emit_output {
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() => {
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let consume = match last_space {
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Some(i) => i + 1,
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None => output.len(),
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};
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println!("{}", out);
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(val.to_owned(), ncount)
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println!("{}", &output[..consume]);
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output.replace_range(..consume, "");
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char_count = output.len();
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// we know there are no tabs left in output, so each char counts
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// as 1 column
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col_count = char_count;
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last_space = None;
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};
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output = val;
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count = ncount;
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}
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loop {
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if let Ok(0) = file.read_line(&mut line) {
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break;
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}
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for ch in line.chars() {
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if ch == '\n' {
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// make sure to _not_ split output at whitespace, since we
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// know the entire output will fit
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last_space = None;
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emit_output!();
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break;
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}
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if col_count >= width {
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emit_output!();
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}
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match ch {
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'\t' => {
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count += 8;
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if count > width {
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println!("{}", output);
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output.truncate(0);
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count = 8;
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if col_count + 8 > width && !output.is_empty() {
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emit_output!();
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}
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col_count += 8;
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last_space = Some(char_count);
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}
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'\x08' => {
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if count > 0 {
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count -= 1;
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let len = output.len() - 1;
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output.truncate(len);
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// FIXME: does not match GNU's handling of backspace
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if col_count > 0 {
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col_count -= 1;
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char_count -= 1;
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output.truncate(char_count);
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}
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continue;
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}
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'\r' => {
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// FIXME: does not match GNU's handling of carriage return
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output.truncate(0);
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count = 0;
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col_count = 0;
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char_count = 0;
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continue;
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}
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_ => count += 1,
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_ if spaces && ch.is_whitespace() => {
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last_space = Some(char_count);
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col_count += 1
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}
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_ => col_count += 1,
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};
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output.push(ch);
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}
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if count > 0 {
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println!("{}", output);
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}
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}
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}
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char_count += 1;
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}
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#[inline]
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fn rfind_whitespace(slice: &str) -> Option<usize> {
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for (i, ch) in slice.chars().rev().enumerate() {
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if ch.is_whitespace() {
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return Some(slice.chars().count() - (i + 1));
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if col_count > 0 {
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print!("{}", output);
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output.truncate(0);
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}
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line.truncate(0);
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}
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}
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None
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}
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@ -32,6 +32,24 @@ fn test_default_wrap_with_newlines() {
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.stdout_is_fixture("lorem_ipsum_new_line_80_column.expected");
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}
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#[test]
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fn test_should_preserve_empty_line_without_final_newline() {
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new_ucmd!()
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.arg("-w2")
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.pipe_in("12\n\n34")
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.succeeds()
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.stdout_is("12\n\n34");
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}
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#[test]
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fn test_should_preserve_empty_line_and_final_newline() {
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new_ucmd!()
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.arg("-w2")
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.pipe_in("12\n\n34\n")
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.succeeds()
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.stdout_is("12\n\n34\n");
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}
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#[test]
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fn test_should_preserve_empty_lines() {
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new_ucmd!().pipe_in("\n").succeeds().stdout_is("\n");
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@ -57,3 +75,262 @@ fn test_word_boundary_split_should_preserve_empty_lines() {
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.succeeds()
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.stdout_is("0\n1\n\n2\n\n\n");
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}
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#[test]
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fn test_should_not_add_newline_when_line_less_than_fold() {
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new_ucmd!().pipe_in("1234").succeeds().stdout_is("1234");
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}
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#[test]
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fn test_should_not_add_newline_when_line_longer_than_fold() {
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new_ucmd!()
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.arg("-w2")
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.pipe_in("1234")
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.succeeds()
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.stdout_is("12\n34");
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}
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#[test]
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fn test_should_not_add_newline_when_line_equal_to_fold() {
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new_ucmd!()
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.arg("-w1")
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.pipe_in(" ")
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.succeeds()
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.stdout_is(" ");
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}
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#[test]
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fn test_should_preserve_final_newline_when_line_less_than_fold() {
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new_ucmd!().pipe_in("1234\n").succeeds().stdout_is("1234\n");
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}
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#[test]
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fn test_should_preserve_final_newline_when_line_longer_than_fold() {
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new_ucmd!()
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.arg("-w2")
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.pipe_in("1234\n")
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.succeeds()
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.stdout_is("12\n34\n");
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}
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#[test]
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fn test_should_preserve_final_newline_when_line_equal_to_fold() {
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new_ucmd!()
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.arg("-w2")
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.pipe_in("1\n")
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.succeeds()
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.stdout_is("1\n");
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}
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#[test]
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fn test_single_tab_should_not_add_extra_newline() {
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new_ucmd!()
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.arg("-w1")
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.pipe_in("\t")
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.succeeds()
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.stdout_is("\t");
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}
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#[test]
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fn test_tab_counts_as_8_columns() {
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new_ucmd!()
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.arg("-w8")
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.pipe_in("\t1")
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.succeeds()
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.stdout_is("\t\n1");
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}
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#[test]
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fn test_fold_at_word_boundary() {
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new_ucmd!()
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.args(&["-w4", "-s"])
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.pipe_in("one two")
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.succeeds()
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.stdout_is("one \ntwo");
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}
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#[test]
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fn test_fold_at_leading_word_boundary() {
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new_ucmd!()
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.args(&["-w3", "-s"])
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.pipe_in(" aaa")
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.succeeds()
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.stdout_is(" \naaa");
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}
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#[test]
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fn test_fold_at_word_boundary_preserve_final_newline() {
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new_ucmd!()
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.args(&["-w4", "-s"])
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.pipe_in("one two\n")
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.succeeds()
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.stdout_is("one \ntwo\n");
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}
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#[test]
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fn test_fold_at_tab_as_word_boundary() {
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new_ucmd!()
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.args(&["-w10", "-s"])
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.pipe_in("a\tbbb\n")
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.succeeds()
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.stdout_is("a\t\nbbb\n");
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}
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#[test]
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fn test_fold_at_word_boundary_only_whitespace() {
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new_ucmd!()
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.args(&["-w2", "-s"])
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.pipe_in(" ")
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.succeeds()
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.stdout_is(" \n ");
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}
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#[test]
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fn test_fold_at_word_boundary_only_whitespace_preserve_final_newline() {
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new_ucmd!()
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.args(&["-w2", "-s"])
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.pipe_in(" \n")
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.succeeds()
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.stdout_is(" \n \n");
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}
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//
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// bytewise tests
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#[test]
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fn test_bytewise_should_preserve_empty_line_without_final_newline() {
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new_ucmd!()
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.args(&["-w2", "-b"])
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.pipe_in("123\n\n45")
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.succeeds()
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.stdout_is("12\n3\n\n45");
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}
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#[test]
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fn test_bytewise_should_preserve_empty_line_and_final_newline() {
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new_ucmd!()
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.args(&["-w2", "-b"])
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.pipe_in("12\n\n34\n")
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.succeeds()
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.stdout_is("12\n\n34\n");
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}
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#[test]
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fn test_bytewise_should_preserve_empty_lines() {
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new_ucmd!()
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.arg("-b")
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.pipe_in("\n")
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.succeeds()
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.stdout_is("\n");
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new_ucmd!()
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.args(&["-w1", "-b"])
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.pipe_in("0\n1\n\n2\n\n\n")
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.succeeds()
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.stdout_is("0\n1\n\n2\n\n\n");
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}
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#[test]
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fn test_bytewise_word_boundary_split_should_preserve_empty_lines() {
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new_ucmd!()
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.args(&["-s", "-b"])
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.pipe_in("\n")
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.succeeds()
|
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.stdout_is("\n");
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|
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new_ucmd!()
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.args(&["-w1", "-s", "-b"])
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.pipe_in("0\n1\n\n2\n\n\n")
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.succeeds()
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.stdout_is("0\n1\n\n2\n\n\n");
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}
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|
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#[test]
|
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fn test_bytewise_should_not_add_newline_when_line_less_than_fold() {
|
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new_ucmd!()
|
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.arg("-b")
|
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.pipe_in("1234")
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.succeeds()
|
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.stdout_is("1234");
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}
|
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|
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#[test]
|
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fn test_bytewise_should_not_add_newline_when_line_longer_than_fold() {
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new_ucmd!()
|
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.args(&["-w2", "-b"])
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.pipe_in("1234")
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.succeeds()
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.stdout_is("12\n34");
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}
|
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|
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#[test]
|
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fn test_bytewise_should_not_add_newline_when_line_equal_to_fold() {
|
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new_ucmd!()
|
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.args(&["-w1", "-b"])
|
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.pipe_in(" ")
|
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.succeeds()
|
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.stdout_is(" ");
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}
|
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|
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#[test]
|
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fn test_bytewise_should_preserve_final_newline_when_line_less_than_fold() {
|
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new_ucmd!()
|
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.arg("-b")
|
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.pipe_in("1234\n")
|
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.succeeds()
|
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.stdout_is("1234\n");
|
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}
|
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|
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#[test]
|
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fn test_bytewise_should_preserve_final_newline_when_line_longer_than_fold() {
|
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new_ucmd!()
|
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.args(&["-w2", "-b"])
|
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.pipe_in("1234\n")
|
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.succeeds()
|
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.stdout_is("12\n34\n");
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}
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|
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#[test]
|
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fn test_bytewise_should_preserve_final_newline_when_line_equal_to_fold() {
|
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new_ucmd!()
|
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.args(&["-w2", "-b"])
|
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.pipe_in("1\n")
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.succeeds()
|
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.stdout_is("1\n");
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}
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#[test]
|
||||
fn test_bytewise_single_tab_should_not_add_extra_newline() {
|
||||
new_ucmd!()
|
||||
.args(&["-w1", "-b"])
|
||||
.pipe_in("\t")
|
||||
.succeeds()
|
||||
.stdout_is("\t");
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_tab_counts_as_one_byte() {
|
||||
new_ucmd!()
|
||||
.args(&["-w2", "-b"])
|
||||
.pipe_in("1\t2\n")
|
||||
.succeeds()
|
||||
.stdout_is("1\t\n2\n");
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_bytewise_fold_at_word_boundary_only_whitespace() {
|
||||
new_ucmd!()
|
||||
.args(&["-w2", "-s", "-b"])
|
||||
.pipe_in(" ")
|
||||
.succeeds()
|
||||
.stdout_is(" \n ");
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_bytewise_fold_at_word_boundary_only_whitespace_preserve_final_newline() {
|
||||
new_ucmd!()
|
||||
.args(&["-w2", "-s", "-b"])
|
||||
.pipe_in(" \n")
|
||||
.succeeds()
|
||||
.stdout_is(" \n \n");
|
||||
}
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue