use std::ffi::OsString;
use std::path::PathBuf;
use regex::Regex;
#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
pub enum Format {
#[default]
Normal,
Unified,
Context,
Ed,
}
#[derive(Clone, Debug, Eq, PartialEq)]
pub struct Params {
pub from: OsString,
pub to: OsString,
pub format: Format,
pub context_count: usize,
pub report_identical_files: bool,
pub brief: bool,
pub expand_tabs: bool,
pub tabsize: usize,
}
impl Default for Params {
fn default() -> Self {
Self {
from: OsString::default(),
to: OsString::default(),
format: Format::default(),
context_count: 3,
report_identical_files: false,
brief: false,
expand_tabs: false,
tabsize: 8,
}
}
}
pub fn parse_params<I: IntoIterator<Item = OsString>>(opts: I) -> Result<Params, String> {
let mut opts = opts.into_iter().peekable();
let Some(exe) = opts.next() else {
return Err("Usage: <exe> <from> <to>".to_string());
};
let mut params = Params::default();
let mut from = None;
let mut to = None;
let mut format = None;
let mut context = None;
let tabsize_re = Regex::new(r"^--tabsize=(?<num>\d+)$").unwrap();
while let Some(param) = opts.next() {
let next_param = opts.peek();
if param == "--" {
break;
}
if param == "-" {
if from.is_none() {
from = Some(param);
} else if to.is_none() {
to = Some(param);
} else {
return Err(format!("Usage: {} <from> <to>", exe.to_string_lossy()));
}
continue;
}
if param == "-s" || param == "--report-identical-files" {
params.report_identical_files = true;
continue;
}
if param == "-q" || param == "--brief" {
params.brief = true;
continue;
}
if param == "-t" || param == "--expand-tabs" {
params.expand_tabs = true;
continue;
}
if param == "--normal" {
if format.is_some() && format != Some(Format::Normal) {
return Err("Conflicting output style options".to_string());
}
format = Some(Format::Normal);
continue;
}
if param == "-e" || param == "--ed" {
if format.is_some() && format != Some(Format::Ed) {
return Err("Conflicting output style options".to_string());
}
format = Some(Format::Ed);
continue;
}
if tabsize_re.is_match(param.to_string_lossy().as_ref()) {
let param = param.into_string().unwrap();
let tabsize_str = tabsize_re
.captures(param.as_str())
.unwrap()
.name("num")
.unwrap()
.as_str();
params.tabsize = match tabsize_str.parse::<usize>() {
Ok(num) => num,
Err(_) => return Err(format!("invalid tabsize «{tabsize_str}»")),
};
continue;
}
match match_context_diff_params(¶m, next_param, format) {
Ok(DiffStyleMatch {
is_match,
context_count,
next_param_consumed,
}) => {
if is_match {
format = Some(Format::Context);
if context_count.is_some() {
context = context_count;
}
if next_param_consumed {
opts.next();
}
continue;
}
}
Err(error) => return Err(error),
}
match match_unified_diff_params(¶m, next_param, format) {
Ok(DiffStyleMatch {
is_match,
context_count,
next_param_consumed,
}) => {
if is_match {
format = Some(Format::Unified);
if context_count.is_some() {
context = context_count;
}
if next_param_consumed {
opts.next();
}
continue;
}
}
Err(error) => return Err(error),
}
if param.to_string_lossy().starts_with('-') {
return Err(format!("Unknown option: {:?}", param));
}
if from.is_none() {
from = Some(param);
} else if to.is_none() {
to = Some(param);
} else {
return Err(format!("Usage: {} <from> <to>", exe.to_string_lossy()));
}
}
params.from = if let Some(from) = from {
from
} else if let Some(param) = opts.next() {
param
} else {
return Err(format!("Usage: {} <from> <to>", exe.to_string_lossy()));
};
params.to = if let Some(to) = to {
to
} else if let Some(param) = opts.next() {
param
} else {
return Err(format!("Usage: {} <from> <to>", exe.to_string_lossy()));
};
let mut from_path: PathBuf = PathBuf::from(¶ms.from);
let mut to_path: PathBuf = PathBuf::from(¶ms.to);
if from_path.is_dir() && to_path.is_file() {
from_path.push(to_path.file_name().unwrap());
params.from = from_path.into_os_string();
} else if from_path.is_file() && to_path.is_dir() {
to_path.push(from_path.file_name().unwrap());
params.to = to_path.into_os_string();
}
params.format = format.unwrap_or(Format::default());
if let Some(context_count) = context {
params.context_count = context_count;
}
Ok(params)
}
struct DiffStyleMatch {
is_match: bool,
context_count: Option<usize>,
next_param_consumed: bool,
}
fn match_context_diff_params(
param: &OsString,
next_param: Option<&OsString>,
format: Option<Format>,
) -> Result<DiffStyleMatch, String> {
const CONTEXT_RE: &str = r"^(-[cC](?<num1>\d*)|--context(=(?<num2>\d*))?|-(?<num3>\d+)c)$";
let regex = Regex::new(CONTEXT_RE).unwrap();
let is_match = regex.is_match(param.to_string_lossy().as_ref());
let mut context_count = None;
let mut next_param_consumed = false;
if is_match {
if format.is_some() && format != Some(Format::Context) {
return Err("Conflicting output style options".to_string());
}
let captures = regex.captures(param.to_str().unwrap()).unwrap();
let num = captures
.name("num1")
.or(captures.name("num2"))
.or(captures.name("num3"));
if let Some(numvalue) = num {
if !numvalue.as_str().is_empty() {
context_count = Some(numvalue.as_str().parse::<usize>().unwrap());
}
}
if param == "-C" && next_param.is_some() {
match next_param.unwrap().to_string_lossy().parse::<usize>() {
Ok(context_size) => {
context_count = Some(context_size);
next_param_consumed = true;
}
Err(_) => {
return Err(format!(
"invalid context length '{}'",
next_param.unwrap().to_string_lossy()
))
}
}
}
}
Ok(DiffStyleMatch {
is_match,
context_count,
next_param_consumed,
})
}
fn match_unified_diff_params(
param: &OsString,
next_param: Option<&OsString>,
format: Option<Format>,
) -> Result<DiffStyleMatch, String> {
const UNIFIED_RE: &str = r"^(-[uU](?<num1>\d*)|--unified(=(?<num2>\d*))?|-(?<num3>\d+)u)$";
let regex = Regex::new(UNIFIED_RE).unwrap();
let is_match = regex.is_match(param.to_string_lossy().as_ref());
let mut context_count = None;
let mut next_param_consumed = false;
if is_match {
if format.is_some() && format != Some(Format::Unified) {
return Err("Conflicting output style options".to_string());
}
let captures = regex.captures(param.to_str().unwrap()).unwrap();
let num = captures
.name("num1")
.or(captures.name("num2"))
.or(captures.name("num3"));
if let Some(numvalue) = num {
if !numvalue.as_str().is_empty() {
context_count = Some(numvalue.as_str().parse::<usize>().unwrap());
}
}
if param == "-U" && next_param.is_some() {
match next_param.unwrap().to_string_lossy().parse::<usize>() {
Ok(context_size) => {
context_count = Some(context_size);
next_param_consumed = true;
}
Err(_) => {
return Err(format!(
"invalid context length '{}'",
next_param.unwrap().to_string_lossy()
))
}
}
}
}
Ok(DiffStyleMatch {
is_match,
context_count,
next_param_consumed,
})
}
#[cfg(test)]
mod tests {
use super::*;
fn os(s: &str) -> OsString {
OsString::from(s)
}
#[test]
fn basics() {
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
..Default::default()
}),
parse_params([os("diff"), os("foo"), os("bar")].iter().cloned())
);
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
..Default::default()
}),
parse_params(
[os("diff"), os("--normal"), os("foo"), os("bar")]
.iter()
.cloned()
)
);
}
#[test]
fn basics_ed() {
for arg in ["-e", "--ed"] {
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
format: Format::Ed,
..Default::default()
}),
parse_params([os("diff"), os(arg), os("foo"), os("bar")].iter().cloned())
);
}
}
#[test]
fn context_valid() {
for args in [vec!["-c"], vec!["--context"], vec!["--context="]] {
let mut params = vec!["diff"];
params.extend(args);
params.extend(["foo", "bar"]);
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
format: Format::Context,
..Default::default()
}),
parse_params(params.iter().map(|x| os(x)))
);
}
for args in [
vec!["-c42"],
vec!["-C42"],
vec!["-C", "42"],
vec!["--context=42"],
vec!["-42c"],
] {
let mut params = vec!["diff"];
params.extend(args);
params.extend(["foo", "bar"]);
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
format: Format::Context,
context_count: 42,
..Default::default()
}),
parse_params(params.iter().map(|x| os(x)))
);
}
}
#[test]
fn context_invalid() {
for args in [
vec!["-c", "42"],
vec!["-c=42"],
vec!["-c="],
vec!["-C"],
vec!["-C=42"],
vec!["-C="],
vec!["--context42"],
vec!["--context", "42"],
vec!["-42C"],
] {
let mut params = vec!["diff"];
params.extend(args);
params.extend(["foo", "bar"]);
assert!(parse_params(params.iter().map(|x| os(x))).is_err());
}
}
#[test]
fn unified_valid() {
for args in [vec!["-u"], vec!["--unified"], vec!["--unified="]] {
let mut params = vec!["diff"];
params.extend(args);
params.extend(["foo", "bar"]);
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
format: Format::Unified,
..Default::default()
}),
parse_params(params.iter().map(|x| os(x)))
);
}
for args in [
vec!["-u42"],
vec!["-U42"],
vec!["-U", "42"],
vec!["--unified=42"],
vec!["-42u"],
] {
let mut params = vec!["diff"];
params.extend(args);
params.extend(["foo", "bar"]);
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
format: Format::Unified,
context_count: 42,
..Default::default()
}),
parse_params(params.iter().map(|x| os(x)))
);
}
}
#[test]
fn unified_invalid() {
for args in [
vec!["-u", "42"],
vec!["-u=42"],
vec!["-u="],
vec!["-U"],
vec!["-U=42"],
vec!["-U="],
vec!["--unified42"],
vec!["--unified", "42"],
vec!["-42U"],
] {
let mut params = vec!["diff"];
params.extend(args);
params.extend(["foo", "bar"]);
assert!(parse_params(params.iter().map(|x| os(x))).is_err());
}
}
#[test]
fn context_count() {
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
format: Format::Unified,
context_count: 54,
..Default::default()
}),
parse_params(
[os("diff"), os("-u54"), os("foo"), os("bar")]
.iter()
.cloned()
)
);
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
format: Format::Unified,
context_count: 54,
..Default::default()
}),
parse_params(
[os("diff"), os("-U54"), os("foo"), os("bar")]
.iter()
.cloned()
)
);
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
format: Format::Unified,
context_count: 54,
..Default::default()
}),
parse_params(
[os("diff"), os("-U"), os("54"), os("foo"), os("bar")]
.iter()
.cloned()
)
);
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
format: Format::Context,
context_count: 54,
..Default::default()
}),
parse_params(
[os("diff"), os("-c54"), os("foo"), os("bar")]
.iter()
.cloned()
)
);
}
#[test]
fn report_identical_files() {
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
..Default::default()
}),
parse_params([os("diff"), os("foo"), os("bar")].iter().cloned())
);
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
report_identical_files: true,
..Default::default()
}),
parse_params([os("diff"), os("-s"), os("foo"), os("bar")].iter().cloned())
);
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
report_identical_files: true,
..Default::default()
}),
parse_params(
[
os("diff"),
os("--report-identical-files"),
os("foo"),
os("bar"),
]
.iter()
.cloned()
)
);
}
#[test]
fn brief() {
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
..Default::default()
}),
parse_params([os("diff"), os("foo"), os("bar")].iter().cloned())
);
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
brief: true,
..Default::default()
}),
parse_params([os("diff"), os("-q"), os("foo"), os("bar")].iter().cloned())
);
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
brief: true,
..Default::default()
}),
parse_params(
[os("diff"), os("--brief"), os("foo"), os("bar"),]
.iter()
.cloned()
)
);
}
#[test]
fn expand_tabs() {
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
..Default::default()
}),
parse_params([os("diff"), os("foo"), os("bar")].iter().cloned())
);
for option in ["-t", "--expand-tabs"] {
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
expand_tabs: true,
..Default::default()
}),
parse_params(
[os("diff"), os(option), os("foo"), os("bar")]
.iter()
.cloned()
)
);
}
}
#[test]
fn tabsize() {
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
..Default::default()
}),
parse_params([os("diff"), os("foo"), os("bar")].iter().cloned())
);
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
tabsize: 0,
..Default::default()
}),
parse_params(
[os("diff"), os("--tabsize=0"), os("foo"), os("bar")]
.iter()
.cloned()
)
);
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("bar"),
tabsize: 42,
..Default::default()
}),
parse_params(
[os("diff"), os("--tabsize=42"), os("foo"), os("bar")]
.iter()
.cloned()
)
);
assert!(parse_params(
[os("diff"), os("--tabsize"), os("foo"), os("bar")]
.iter()
.cloned()
)
.is_err());
assert!(parse_params(
[os("diff"), os("--tabsize="), os("foo"), os("bar")]
.iter()
.cloned()
)
.is_err());
assert!(parse_params(
[os("diff"), os("--tabsize=r2"), os("foo"), os("bar")]
.iter()
.cloned()
)
.is_err());
assert!(parse_params(
[os("diff"), os("--tabsize=-1"), os("foo"), os("bar")]
.iter()
.cloned()
)
.is_err());
assert!(parse_params(
[os("diff"), os("--tabsize=r2"), os("foo"), os("bar")]
.iter()
.cloned()
)
.is_err());
assert!(parse_params(
[
os("diff"),
os("--tabsize=92233720368547758088"),
os("foo"),
os("bar")
]
.iter()
.cloned()
)
.is_err());
}
#[test]
fn double_dash() {
assert_eq!(
Ok(Params {
from: os("-g"),
to: os("-h"),
..Default::default()
}),
parse_params([os("diff"), os("--"), os("-g"), os("-h")].iter().cloned())
);
}
#[test]
fn default_to_stdin() {
assert_eq!(
Ok(Params {
from: os("foo"),
to: os("-"),
..Default::default()
}),
parse_params([os("diff"), os("foo"), os("-")].iter().cloned())
);
assert_eq!(
Ok(Params {
from: os("-"),
to: os("bar"),
..Default::default()
}),
parse_params([os("diff"), os("-"), os("bar")].iter().cloned())
);
assert_eq!(
Ok(Params {
from: os("-"),
to: os("-"),
..Default::default()
}),
parse_params([os("diff"), os("-"), os("-")].iter().cloned())
);
assert!(parse_params([os("diff"), os("foo"), os("bar"), os("-")].iter().cloned()).is_err());
assert!(parse_params([os("diff"), os("-"), os("-"), os("-")].iter().cloned()).is_err());
}
#[test]
fn missing_arguments() {
assert!(parse_params([os("diff")].iter().cloned()).is_err());
assert!(parse_params([os("diff"), os("foo")].iter().cloned()).is_err());
}
#[test]
fn unknown_argument() {
assert!(
parse_params([os("diff"), os("-g"), os("foo"), os("bar")].iter().cloned()).is_err()
);
assert!(parse_params([os("diff"), os("-g"), os("bar")].iter().cloned()).is_err());
assert!(parse_params([os("diff"), os("-g")].iter().cloned()).is_err());
}
#[test]
fn empty() {
assert!(parse_params([].iter().cloned()).is_err());
}
#[test]
fn conflicting_output_styles() {
for (arg1, arg2) in [
("-u", "-c"),
("-u", "-e"),
("-c", "-u"),
("-c", "-U42"),
("-u", "--normal"),
("--normal", "-e"),
("--context", "--normal"),
] {
assert!(parse_params(
[os("diff"), os(arg1), os(arg2), os("foo"), os("bar")]
.iter()
.cloned()
)
.is_err());
}
}
}