src/source_file.rs

   1 use std::fs;
   2 use std::io::{self, Write};
   3
   4 use crate::checkstyle::output_checkstyle_file;
   5 use crate::config::{Config, EmitMode, FileName, Verbosity};
   6 use crate::rustfmt_diff::{make_diff, output_modified, print_diff};
   7
   8 #[cfg(test)]
   9 use crate::formatting::FileRecord;
  10
  11 // Append a newline to the end of each file.
  12 pub fn append_newline(s: &mut String) {
  13     s.push_str("\n");
  14 }
  15
  16 #[cfg(test)]
  17 pub(crate) fn write_all_files<T>(
  18     source_file: &[FileRecord],
  19     out: &mut T,
  20     config: &Config,
  21 ) -> Result<(), io::Error>
  22 where
  23     T: Write,
  24 {
  25     if config.emit_mode() == EmitMode::Checkstyle {
  26         write!(out, "{}", crate::checkstyle::header())?;
  27     }
  28     for &(ref filename, ref text) in source_file {
  29         write_file(text, filename, out, config)?;
  30     }
  31     if config.emit_mode() == EmitMode::Checkstyle {
  32         write!(out, "{}", crate::checkstyle::footer())?;
  33     }
  34
  35     Ok(())
  36 }
  37
  38 pub fn write_file<T>(
  39     formatted_text: &str,
  40     filename: &FileName,
  41     out: &mut T,
  42     config: &Config,
  43 ) -> Result<bool, io::Error>
  44 where
  45     T: Write,
  46 {
  47     let filename_to_path = || match *filename {
  48         FileName::Real(ref path) => path,
  49         _ => panic!("cannot format `{}` and emit to files", filename),
  50     };
  51
  52     match config.emit_mode() {
  53         EmitMode::Files if config.make_backup() => {
  54             let filename = filename_to_path();
  55             let ori = fs::read_to_string(filename)?;
  56             if ori != formatted_text {
  57                 // Do a little dance to make writing safer - write to a temp file
  58                 // rename the original to a .bk, then rename the temp file to the
  59                 // original.
  60                 let tmp_name = filename.with_extension("tmp");
  61                 let bk_name = filename.with_extension("bk");
  62
  63                 fs::write(&tmp_name, formatted_text)?;
  64                 fs::rename(filename, bk_name)?;
  65                 fs::rename(tmp_name, filename)?;
  66             }
  67         }
  68         EmitMode::Files => {
  69             // Write text directly over original file if there is a diff.
  70             let filename = filename_to_path();
  71             let ori = fs::read_to_string(filename)?;
  72             if ori != formatted_text {
  73                 fs::write(filename, formatted_text)?;
  74             }
  75         }
  76         EmitMode::Stdout | EmitMode::Coverage => {
  77             if config.verbose() != Verbosity::Quiet {
  78                 println!("{}:\n", filename);
  79             }
  80             write!(out, "{}", formatted_text)?;
  81         }
  82         EmitMode::ModifiedLines => {
  83             let filename = filename_to_path();
  84             let ori = fs::read_to_string(filename)?;
  85             let mismatch = make_diff(&ori, formatted_text, 0);
  86             let has_diff = !mismatch.is_empty();
  87             output_modified(out, mismatch);
  88             return Ok(has_diff);
  89         }
  90         EmitMode::Checkstyle => {
  91             let filename = filename_to_path();
  92             let ori = fs::read_to_string(filename)?;
  93             let diff = make_diff(&ori, formatted_text, 3);
  94             output_checkstyle_file(out, filename, diff)?;
  95         }
  96         EmitMode::Diff => {
  97             let filename = filename_to_path();
  98             let ori = fs::read_to_string(filename)?;
  99             let mismatch = make_diff(&ori, formatted_text, 3);
 100             let has_diff = !mismatch.is_empty();
 101             print_diff(
 102                 mismatch,
 103                 |line_num| format!("Diff in {} at line {}:", filename.display(), line_num),
 104                 config,
 105             );
 106             return Ok(has_diff);
 107         }
 108     }
 109
 110     // when we are not in diff mode, don't indicate differing files
 111     Ok(false)
 112 }