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|
use std::path::Path;
use crate::config::{self};
use crate::utils::git::retrieve_git_version;
use crate::subcommands::{SubCmdKind, SubCommand};
use std::ffi::OsString;
/// Build `git diff` command for the files provided on the command line. Fall back to
/// `diff` if the supplied "files" use process substitution.
pub fn build_diff_cmd(
minus_file: &Path,
plus_file: &Path,
config: &config::Config,
) -> Result<SubCommand, i32> {
// suppress `dead_code` warning, values are accessed via `get_one::<PathBuf>("plus/minus_file")`
debug_assert!(config.minus_file.as_ref().unwrap() == minus_file);
debug_assert!(config.plus_file.as_ref().unwrap() == plus_file);
let mut diff_args = match shell_words::split(config.diff_args.trim()) {
Ok(words) => words,
Err(err) => {
eprintln!("Failed to parse diff args: {}: {err}", config.diff_args);
return Err(config.error_exit_code);
}
};
// Permit e.g. -@U1
if diff_args
.first()
.map(|arg| !arg.is_empty() && !arg.starts_with('-'))
.unwrap_or(false)
{
diff_args[0] = format!("-{}", diff_args[0])
}
let via_process_substitution =
|f: &Path| f.starts_with("/proc/self/fd/") || f.starts_with("/dev/fd/");
// https://stackoverflow.com/questions/22706714/why-does-git-diff-not-work-with-process-substitution
// git <2.42 does not support process substitution
let (differ, mut diff_cmd) = match retrieve_git_version() {
Some(version)
if version >= (2, 42)
|| !(via_process_substitution(minus_file)
|| via_process_substitution(plus_file)) =>
{
(
SubCmdKind::GitDiff,
vec!["git", "diff", "--no-index", "--color"],
)
}
_ => (
SubCmdKind::Diff,
if diff_args_set_unified_context(&diff_args) {
vec!["diff"]
} else {
vec!["diff", "-U3"]
},
),
};
diff_cmd.extend(
diff_args
.iter()
.filter(|s| !s.is_empty())
.map(String::as_str),
);
diff_cmd.push("--");
let mut diff_cmd = diff_cmd.iter().map(OsString::from).collect::<Vec<_>>();
diff_cmd.push(minus_file.into());
diff_cmd.push(plus_file.into());
Ok(SubCommand::new(differ, diff_cmd))
}
/// Do the user-supplied `diff` args set the unified context?
fn diff_args_set_unified_context<I, S>(args: I) -> bool
where
I: IntoIterator<Item = S>,
S: AsRef<str>,
{
// This function is applied to `diff` args; not `git diff`.
for arg in args {
let arg = arg.as_ref();
if arg == "-u" || arg == "-U" {
// diff allows a space after -U (git diff does not)
return true;
}
if (arg.starts_with("-U") || arg.starts_with("-u"))
&& arg.split_at(2).1.parse::<u32>().is_ok()
{
return true;
}
}
false
}
#[cfg(test)]
mod main_tests {
use std::ffi::OsString;
use std::io::Cursor;
use super::diff_args_set_unified_context;
use rstest::rstest;
#[rstest]
#[case(&["-u"], true)]
#[case(&["-u7"], true)]
#[case(&["-u77"], true)]
#[case(&["-ux"], false)]
#[case(&["-U"], true)]
#[case(&["-U7"], true)]
#[case(&["-U77"], true)]
#[case(&["-Ux"], false)]
fn test_unified_diff_arg_is_detected_in_diff_args(
#[case] diff_args: &[&str],
#[case] expected: bool,
) {
assert_eq!(diff_args_set_unified_context(diff_args), expected)
}
enum ExpectDiff {
Yes,
No,
}
#[cfg(not(target_os = "windows"))]
#[rstest]
// #[case("/dev/null", "/dev/null", ExpectDiff::No)] https://github.com/dandavison/delta/pull/546#issuecomment-835852373
#[case("/etc/group", "/etc/passwd", ExpectDiff::Yes)]
#[case("/dev/null", "/etc/passwd", ExpectDiff::Yes)]
#[case("/etc/passwd", "/etc/passwd", ExpectDiff::No)]
fn test_diff_real_files(
#[case] file_a: &str,
#[case] file_b: &str,
#[case] expect_diff: ExpectDiff,
#[values(vec![], vec!["-@''"], vec!["-@-u"], vec!["-@-U99"], vec!["-@-U0"])] args: Vec<
&str,
>,
) {
let mut writer = Cursor::new(vec![]);
let mut runargs = vec![OsString::from(file_a), OsString::from(file_b)];
runargs.extend(args.iter().map(OsString::from));
let exit_code = crate::run_app(runargs, Some(&mut writer));
assert_eq!(
exit_code.unwrap(),
match expect_diff {
ExpectDiff::Yes => 1,
ExpectDiff::No => 0,
}
);
assert_eq!(
std::str::from_utf8(writer.get_ref()).unwrap() != "",
match expect_diff {
ExpectDiff::Yes => true,
ExpectDiff::No => false,
}
);
}
}
|
