coreutils/tests/by-util/test_tac.rs
Jeffrey Finkelstein 0e689e78aa tac: support multi-char separator with overlap
Fix a bug in `tac` where multi-character line separators would cause
incorrect behavior when there was overlap between candidate matches in
the input string. This commit adds a dependency on `memchr` in order to
use the `memchr::memmem::rfind_iter()` function to scan for
non-overlapping instances of the specified line separator characters,
scanning from right to left.

Fixes #2580.
2021-08-23 20:16:38 -04:00

207 lines
5.3 KiB
Rust

// spell-checker:ignore axxbxx bxxaxx axxx axxxx xxaxx xxax xxxxa
use crate::common::util::*;
#[test]
fn test_stdin_default() {
new_ucmd!()
.pipe_in("100\n200\n300\n400\n500")
.run()
.stdout_is("500400\n300\n200\n100\n");
}
#[test]
fn test_stdin_non_newline_separator() {
new_ucmd!()
.args(&["-s", ":"])
.pipe_in("100:200:300:400:500")
.run()
.stdout_is("500400:300:200:100:");
}
#[test]
fn test_stdin_non_newline_separator_before() {
new_ucmd!()
.args(&["-b", "-s", ":"])
.pipe_in("100:200:300:400:500")
.run()
.stdout_is(":500:400:300:200100");
}
#[test]
fn test_single_default() {
new_ucmd!()
.arg("prime_per_line.txt")
.run()
.stdout_is_fixture("prime_per_line.expected");
}
#[test]
fn test_single_non_newline_separator() {
new_ucmd!()
.args(&["-s", ":", "delimited_primes.txt"])
.run()
.stdout_is_fixture("delimited_primes.expected");
}
#[test]
fn test_single_non_newline_separator_before() {
new_ucmd!()
.args(&["-b", "-s", ":", "delimited_primes.txt"])
.run()
.stdout_is_fixture("delimited_primes_before.expected");
}
#[test]
fn test_invalid_input() {
let scene = TestScenario::new(util_name!());
let at = &scene.fixtures;
scene
.ucmd()
.arg("b")
.fails()
.stderr_contains("failed to open 'b' for reading: No such file or directory");
at.mkdir("a");
scene
.ucmd()
.arg("a")
.fails()
.stderr_contains("a: read error: Invalid argument");
}
#[test]
fn test_no_line_separators() {
new_ucmd!().pipe_in("a").succeeds().stdout_is("a");
}
#[test]
fn test_before_trailing_separator_no_leading_separator() {
new_ucmd!()
.arg("-b")
.pipe_in("a\nb\n")
.succeeds()
.stdout_is("\n\nba");
}
#[test]
fn test_before_trailing_separator_and_leading_separator() {
new_ucmd!()
.arg("-b")
.pipe_in("\na\nb\n")
.succeeds()
.stdout_is("\n\nb\na");
}
#[test]
fn test_before_leading_separator_no_trailing_separator() {
new_ucmd!()
.arg("-b")
.pipe_in("\na\nb")
.succeeds()
.stdout_is("\nb\na");
}
#[test]
fn test_before_no_separator() {
new_ucmd!()
.arg("-b")
.pipe_in("ab")
.succeeds()
.stdout_is("ab");
}
#[test]
fn test_before_empty_file() {
new_ucmd!().arg("-b").pipe_in("").succeeds().stdout_is("");
}
#[test]
fn test_multi_char_separator() {
new_ucmd!()
.args(&["-s", "xx"])
.pipe_in("axxbxx")
.succeeds()
.stdout_is("bxxaxx");
}
#[test]
fn test_multi_char_separator_overlap() {
// The right-most pair of "x" characters in the input is treated as
// the only line separator. That is, "axxx" is interpreted as having
// one line comprising the string "ax" followed by the line
// separator "xx".
new_ucmd!()
.args(&["-s", "xx"])
.pipe_in("axxx")
.succeeds()
.stdout_is("axxx");
// Each non-overlapping pair of "x" characters in the input is
// treated as a line separator. That is, "axxxx" is interpreted as
// having two lines:
//
// * the second line is the empty string "" followed by the line
// separator "xx",
// * the first line is the string "a" followed by the line separator
// "xx".
//
// The lines are printed in reverse, resulting in "xx" followed by
// "axx".
new_ucmd!()
.args(&["-s", "xx"])
.pipe_in("axxxx")
.succeeds()
.stdout_is("xxaxx");
}
#[test]
fn test_multi_char_separator_overlap_before() {
// With the "-b" option, the line separator is assumed to be at the
// beginning of the line. In this case, That is, "axxx" is
// interpreted as having two lines:
//
// * the second line is the empty string "" preceded by the line
// separator "xx",
// * the first line is the string "ax" preceded by no line
// separator, since there are no more characters preceding it.
//
// The lines are printed in reverse, resulting in "xx" followed by
// "ax".
new_ucmd!()
.args(&["-b", "-s", "xx"])
.pipe_in("axxx")
.succeeds()
.stdout_is("xxax");
// With the "-b" option, the line separator is assumed to be at the
// beginning of the line. Each non-overlapping pair of "x"
// characters in the input is treated as a line separator. That is,
// "axxxx" is interpreted as having three lines:
//
// * the third line is the empty string "" preceded by the line
// separator "xx" (the last two "x" characters in the input
// string),
// * the second line is the empty string "" preceded by the line
// separator "xx" (the first two "x" characters in the input
// string),
// * the first line is the string "a" preceded by no line separator,
// since there are no more characters preceding it.
//
// The lines are printed in reverse, resulting in "xx" followed by
// "xx" followed by "a".
new_ucmd!()
.args(&["-b", "-s", "xx"])
.pipe_in("axxxx")
.succeeds()
.stdout_is("xxxxa");
}
#[test]
fn test_null_separator() {
new_ucmd!()
.args(&["-s", ""])
.pipe_in("a\0b\0")
.succeeds()
.stdout_is("b\0a\0");
}