Files
uutils-diffutils/src/ed_diff.rs
T
Marc Herbert 1254f146f8 tests: validate "patch" and "ed" commands once, print meaningful messages (#226)
macOS' /usr/bin/patch and GNU patch have very subtle incompatibilities
that cause only some "more advanced" tests to fail in obscure and very
time-consuming ways - while other tests pass. In some cases (depending
on test threads racing), the lack of newlines in some test data even
causes the whole test suite to stall.

This fix runs `patch -version` (only once), makes sure the output starts
with "GNU patch" and shows a meaningful assert message when not. It also
looks for `gpatch` instead of `patch` on macOS and shows a meaningful
assert message if either is missing.

Fixes: #225

This also provides faster and better feedback when `ed` is missing (see
#39) and implements a portable and basic check.

Last but not least, this new code is generic enough to support the
validation of any other test dependency in the future.
2026-05-24 17:08:52 +02:00

453 lines
19 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;
use crate::params::Params;
use crate::utils::do_write_line;
#[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], stop_early: bool) -> 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 stop_early && !results.is_empty() {
// Optimization: stop analyzing the files as soon as there are any differences
return Ok(results);
}
}
if !mismatch.actual.is_empty() || !mismatch.expected.is_empty() {
results.push(mismatch);
}
Ok(results)
}
pub fn diff(expected: &[u8], actual: &[u8], params: &Params) -> Result<Vec<u8>, DiffError> {
let mut output = Vec::new();
let diff_results = make_diff(expected, actual, params.brief)?;
if params.brief && !diff_results.is_empty() {
write!(&mut output, "\0").unwrap();
return Ok(output);
}
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(),
(1, _) => writeln!(&mut output, "{line_number_expected}c").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 {
do_write_line(&mut output, actual, params.expand_tabs, params.tabsize).unwrap();
writeln!(&mut output).unwrap();
}
}
writeln!(&mut output, ".").unwrap();
}
}
Ok(output)
}
#[cfg(test)]
mod tests {
use super::*;
use pretty_assertions::assert_eq;
use crate::utils::testcmds::ED_CMD;
pub fn diff_w(expected: &[u8], actual: &[u8], filename: &str) -> Result<Vec<u8>, DiffError> {
let mut output = diff(expected, actual, &Params::default())?;
writeln!(&mut output, "w {filename}").unwrap();
Ok(output)
}
#[test]
fn test_basic() {
let from = b"a\n";
let to = b"b\n";
let diff = diff(from, to, &Params::default()).unwrap();
let expected = ["1c", "b", ".", ""].join("\n");
assert_eq!(diff, expected.as_bytes());
}
#[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::File;
use std::io::Write;
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(format!("{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;
#[cfg(not(windows))] // there's no ed on windows
{
let output = ED_CMD
.new()
.arg(format!("{target}/alef"))
.stdin(File::open(format!("{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 = std::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::File;
use std::io::Write;
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, &format!("{target}/alef_")).unwrap();
File::create(format!("{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;
#[cfg(not(windows))] // there's no ed on windows
{
let output = ED_CMD
.new()
.arg(format!("{target}/alef_"))
.stdin(File::open(format!("{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 = std::fs::read(format!("{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::File;
use std::io::Write;
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(format!("{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;
#[cfg(not(windows))] // there's no ed on windows
{
let output = ED_CMD
.new()
.arg(format!("{target}/alefr"))
.stdin(File::open(format!("{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 = std::fs::read(format!("{target}/alefr")).unwrap();
assert_eq!(alef, bet);
}
}
}
}
}
}
}
}
#[test]
fn test_stop_early() {
let from = ["a", "b", "c", ""].join("\n");
let to = ["a", "d", "c", ""].join("\n");
let diff_full = diff(from.as_bytes(), to.as_bytes(), &Params::default()).unwrap();
let expected_full = ["2c", "d", ".", ""].join("\n");
assert_eq!(diff_full, expected_full.as_bytes());
let diff_brief = diff(
from.as_bytes(),
to.as_bytes(),
&Params {
brief: true,
..Default::default()
},
)
.unwrap();
let expected_brief = "\0".as_bytes();
assert_eq!(diff_brief, expected_brief);
let nodiff_full = diff(from.as_bytes(), from.as_bytes(), &Params::default()).unwrap();
assert!(nodiff_full.is_empty());
let nodiff_brief = diff(
from.as_bytes(),
from.as_bytes(),
&Params {
brief: true,
..Default::default()
},
)
.unwrap();
assert!(nodiff_brief.is_empty());
}
}