Files
diffutils/src/ed_diff.rs
T
2024-01-23 12:36:57 +01:00

384 lines
17 KiB
Rust

// This file is part of the uutils diffutils package.
//
// For the full copyright and license information, please view the LICENSE-*
// files that was distributed with this source code.
use std::io::Write;
#[derive(Debug, PartialEq)]
struct Mismatch {
pub line_number_expected: usize,
pub line_number_actual: usize,
pub expected: Vec<Vec<u8>>,
pub actual: Vec<Vec<u8>>,
}
#[derive(Debug, PartialEq, Eq)]
pub enum DiffError {
MissingNL,
}
impl std::fmt::Display for DiffError {
fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
std::fmt::Display::fmt("No newline at end of file", f)
}
}
impl From<DiffError> for String {
fn from(_: DiffError) -> String {
"No newline at end of file".into()
}
}
impl Mismatch {
fn new(line_number_expected: usize, line_number_actual: usize) -> Mismatch {
Mismatch {
line_number_expected,
line_number_actual,
expected: Vec::new(),
actual: Vec::new(),
}
}
}
// Produces a diff between the expected output and actual output.
fn make_diff(expected: &[u8], actual: &[u8]) -> Result<Vec<Mismatch>, DiffError> {
let mut line_number_expected = 1;
let mut line_number_actual = 1;
let mut results = Vec::new();
let mut mismatch = Mismatch::new(line_number_expected, line_number_actual);
let mut expected_lines: Vec<&[u8]> = expected.split(|&c| c == b'\n').collect();
let mut actual_lines: Vec<&[u8]> = actual.split(|&c| c == b'\n').collect();
debug_assert_eq!(b"".split(|&c| c == b'\n').count(), 1);
// ^ means that underflow here is impossible
let _expected_lines_count = expected_lines.len() - 1;
let _actual_lines_count = actual_lines.len() - 1;
if expected_lines.last() == Some(&&b""[..]) {
expected_lines.pop();
} else {
return Err(DiffError::MissingNL);
}
if actual_lines.last() == Some(&&b""[..]) {
actual_lines.pop();
} else {
return Err(DiffError::MissingNL);
}
for result in diff::slice(&expected_lines, &actual_lines) {
match result {
diff::Result::Left(str) => {
if !mismatch.actual.is_empty() {
results.push(mismatch);
mismatch = Mismatch::new(line_number_expected, line_number_actual);
}
mismatch.expected.push(str.to_vec());
line_number_expected += 1;
}
diff::Result::Right(str) => {
mismatch.actual.push(str.to_vec());
line_number_actual += 1;
}
diff::Result::Both(_str, _) => {
line_number_expected += 1;
line_number_actual += 1;
if !mismatch.actual.is_empty() || !mismatch.expected.is_empty() {
results.push(mismatch);
mismatch = Mismatch::new(line_number_expected, line_number_actual);
} else {
mismatch.line_number_expected = line_number_expected;
mismatch.line_number_actual = line_number_actual;
}
}
}
}
if !mismatch.actual.is_empty() || !mismatch.expected.is_empty() {
results.push(mismatch);
}
Ok(results)
}
pub fn diff(expected: &[u8], actual: &[u8]) -> Result<Vec<u8>, DiffError> {
let mut output = Vec::new();
let diff_results = make_diff(expected, actual)?;
let mut lines_offset = 0;
for result in diff_results {
let line_number_expected: isize = result.line_number_expected as isize + lines_offset;
let _line_number_actual: isize = result.line_number_actual as isize + lines_offset;
let expected_count: isize = result.expected.len() as isize;
let actual_count: isize = result.actual.len() as isize;
match (expected_count, actual_count) {
(0, 0) => unreachable!(),
(0, _) => writeln!(&mut output, "{}a", line_number_expected - 1).unwrap(),
(_, 0) => writeln!(
&mut output,
"{},{}d",
line_number_expected,
expected_count + line_number_expected - 1
)
.unwrap(),
_ => writeln!(
&mut output,
"{},{}c",
line_number_expected,
expected_count + line_number_expected - 1
)
.unwrap(),
}
lines_offset += actual_count - expected_count;
if actual_count != 0 {
for actual in &result.actual {
if actual == b"." {
writeln!(&mut output, "..\n.\ns/.//\na").unwrap();
} else {
output.write_all(actual).unwrap();
writeln!(&mut output).unwrap();
}
}
writeln!(&mut output, ".").unwrap();
}
}
Ok(output)
}
#[cfg(test)]
mod tests {
use super::*;
use pretty_assertions::assert_eq;
pub fn diff_w(expected: &[u8], actual: &[u8], filename: &str) -> Result<Vec<u8>, DiffError> {
let mut output = diff(expected, actual)?;
writeln!(&mut output, "w {filename}").unwrap();
Ok(output)
}
#[test]
fn test_permutations() {
let target = "target/ed-diff/";
// test all possible six-line files.
let _ = std::fs::create_dir(target);
for &a in &[0, 1, 2] {
for &b in &[0, 1, 2] {
for &c in &[0, 1, 2] {
for &d in &[0, 1, 2] {
for &e in &[0, 1, 2] {
for &f in &[0, 1, 2] {
use std::fs::{self, File};
use std::io::Write;
use std::process::Command;
let mut alef = Vec::new();
let mut bet = Vec::new();
alef.write_all(if a == 0 { b"a\n" } else { b"b\n" })
.unwrap();
if a != 2 {
bet.write_all(b"b\n").unwrap();
}
alef.write_all(if b == 0 { b"c\n" } else { b"d\n" })
.unwrap();
if b != 2 {
bet.write_all(b"d\n").unwrap();
}
alef.write_all(if c == 0 { b"e\n" } else { b"f\n" })
.unwrap();
if c != 2 {
bet.write_all(b"f\n").unwrap();
}
alef.write_all(if d == 0 { b"g\n" } else { b"h\n" })
.unwrap();
if d != 2 {
bet.write_all(b"h\n").unwrap();
}
alef.write_all(if e == 0 { b"i\n" } else { b"j\n" })
.unwrap();
if e != 2 {
bet.write_all(b"j\n").unwrap();
}
alef.write_all(if f == 0 { b"k\n" } else { b"l\n" })
.unwrap();
if f != 2 {
bet.write_all(b"l\n").unwrap();
}
// This test diff is intentionally reversed.
// We want it to turn the alef into bet.
let diff = diff_w(&alef, &bet, &format!("{target}/alef")).unwrap();
File::create("target/ab.ed")
.unwrap()
.write_all(&diff)
.unwrap();
let mut fa = File::create(&format!("{target}/alef")).unwrap();
fa.write_all(&alef[..]).unwrap();
let mut fb = File::create(&format!("{target}/bet")).unwrap();
fb.write_all(&bet[..]).unwrap();
let _ = fa;
let _ = fb;
let output = Command::new("ed")
.arg(&format!("{target}/alef"))
.stdin(File::open("target/ab.ed").unwrap())
.output()
.unwrap();
assert!(output.status.success(), "{:?}", output);
//println!("{}", String::from_utf8_lossy(&output.stdout));
//println!("{}", String::from_utf8_lossy(&output.stderr));
let alef = fs::read(&format!("{target}/alef")).unwrap();
assert_eq!(alef, bet);
}
}
}
}
}
}
}
#[test]
fn test_permutations_empty_lines() {
let target = "target/ed-diff/";
// test all possible six-line files with missing newlines.
let _ = std::fs::create_dir(target);
for &a in &[0, 1, 2] {
for &b in &[0, 1, 2] {
for &c in &[0, 1, 2] {
for &d in &[0, 1, 2] {
for &e in &[0, 1, 2] {
for &f in &[0, 1, 2] {
use std::fs::{self, File};
use std::io::Write;
use std::process::Command;
let mut alef = Vec::new();
let mut bet = Vec::new();
alef.write_all(if a == 0 { b"\n" } else { b"b\n" }).unwrap();
if a != 2 {
bet.write_all(b"b\n").unwrap();
}
alef.write_all(if b == 0 { b"\n" } else { b"d\n" }).unwrap();
if b != 2 {
bet.write_all(b"d\n").unwrap();
}
alef.write_all(if c == 0 { b"\n" } else { b"f\n" }).unwrap();
if c != 2 {
bet.write_all(b"f\n").unwrap();
}
alef.write_all(if d == 0 { b"\n" } else { b"h\n" }).unwrap();
if d != 2 {
bet.write_all(b"h\n").unwrap();
}
alef.write_all(if e == 0 { b"\n" } else { b"j\n" }).unwrap();
if e != 2 {
bet.write_all(b"j\n").unwrap();
}
alef.write_all(if f == 0 { b"\n" } else { b"l\n" }).unwrap();
if f != 2 {
bet.write_all(b"l\n").unwrap();
}
// This test diff is intentionally reversed.
// We want it to turn the alef into bet.
let diff = diff_w(&alef, &bet, "target/alef_").unwrap();
File::create("target/ab_.ed")
.unwrap()
.write_all(&diff)
.unwrap();
let mut fa = File::create("target/alef_").unwrap();
fa.write_all(&alef[..]).unwrap();
let mut fb = File::create(&format!("{target}/bet_")).unwrap();
fb.write_all(&bet[..]).unwrap();
let _ = fa;
let _ = fb;
let output = Command::new("ed")
.arg("target/alef_")
.stdin(File::open("target/ab_.ed").unwrap())
.output()
.unwrap();
assert!(output.status.success(), "{:?}", output);
//println!("{}", String::from_utf8_lossy(&output.stdout));
//println!("{}", String::from_utf8_lossy(&output.stderr));
let alef = fs::read("target/alef_").unwrap();
assert_eq!(alef, bet);
}
}
}
}
}
}
}
#[test]
fn test_permutations_reverse() {
let target = "target/ed-diff/";
// test all possible six-line files.
let _ = std::fs::create_dir(target);
for &a in &[0, 1, 2] {
for &b in &[0, 1, 2] {
for &c in &[0, 1, 2] {
for &d in &[0, 1, 2] {
for &e in &[0, 1, 2] {
for &f in &[0, 1, 2] {
use std::fs::{self, File};
use std::io::Write;
use std::process::Command;
let mut alef = Vec::new();
let mut bet = Vec::new();
alef.write_all(if a == 0 { b"a\n" } else { b"f\n" })
.unwrap();
if a != 2 {
bet.write_all(b"a\n").unwrap();
}
alef.write_all(if b == 0 { b"b\n" } else { b"e\n" })
.unwrap();
if b != 2 {
bet.write_all(b"b\n").unwrap();
}
alef.write_all(if c == 0 { b"c\n" } else { b"d\n" })
.unwrap();
if c != 2 {
bet.write_all(b"c\n").unwrap();
}
alef.write_all(if d == 0 { b"d\n" } else { b"c\n" })
.unwrap();
if d != 2 {
bet.write_all(b"d\n").unwrap();
}
alef.write_all(if e == 0 { b"e\n" } else { b"b\n" })
.unwrap();
if e != 2 {
bet.write_all(b"e\n").unwrap();
}
alef.write_all(if f == 0 { b"f\n" } else { b"a\n" })
.unwrap();
if f != 2 {
bet.write_all(b"f\n").unwrap();
}
// This test diff is intentionally reversed.
// We want it to turn the alef into bet.
let diff = diff_w(&alef, &bet, &format!("{target}/alefr")).unwrap();
File::create("target/abr.ed")
.unwrap()
.write_all(&diff)
.unwrap();
let mut fa = File::create(&format!("{target}/alefr")).unwrap();
fa.write_all(&alef[..]).unwrap();
let mut fb = File::create(&format!("{target}/betr")).unwrap();
fb.write_all(&bet[..]).unwrap();
let _ = fa;
let _ = fb;
let output = Command::new("ed")
.arg(&format!("{target}/alefr"))
.stdin(File::open("target/abr.ed").unwrap())
.output()
.unwrap();
assert!(output.status.success(), "{:?}", output);
//println!("{}", String::from_utf8_lossy(&output.stdout));
//println!("{}", String::from_utf8_lossy(&output.stderr));
let alef = fs::read(&format!("{target}/alefr")).unwrap();
assert_eq!(alef, bet);
}
}
}
}
}
}
}
}