use crate::linter::{Diagnostic, LintResult, Severity, Span};
use regex::Regex;
static UNNECESSARY_SUBSHELL: std::sync::LazyLock<Regex> =
std::sync::LazyLock::new(|| Regex::new(r"\(\s*[a-zA-Z_][a-zA-Z0-9_]*=[^;)]+\s*\)").unwrap());
pub fn check(source: &str) -> LintResult {
let mut result = LintResult::new();
for (line_num, line) in source.lines().enumerate() {
let line_num = line_num + 1;
if line.trim_start().starts_with('#') {
continue;
}
if UNNECESSARY_SUBSHELL.is_match(line) {
let diagnostic = Diagnostic::new(
"SC2268",
Severity::Info,
"Avoid unnecessary subshells for simple assignments".to_string(),
Span::new(line_num, 1, line_num, line.len() + 1),
);
result.add(diagnostic);
}
}
result
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_sc2268_unnecessary_subshell() {
let code = "( var=value )";
assert_eq!(check(code).diagnostics.len(), 1);
}
#[test]
fn test_sc2268_direct_assignment_ok() {
let code = "var=value";
assert_eq!(check(code).diagnostics.len(), 0);
}
#[test]
fn test_sc2268_needed_subshell_ok() {
let code = "( cd /tmp && make )";
assert_eq!(check(code).diagnostics.len(), 0);
}
#[test]
fn test_sc2268_comment() {
let code = "# ( var=value )";
assert_eq!(check(code).diagnostics.len(), 0);
}
#[test]
fn test_sc2268_empty() {
assert_eq!(check("").diagnostics.len(), 0);
}
#[test]
fn test_sc2268_normal() {
assert_eq!(check("echo test").diagnostics.len(), 0);
}
#[test]
fn test_sc2268_command_substitution_ok() {
let code = "result=$(command)";
assert_eq!(check(code).diagnostics.len(), 0);
}
#[test]
fn test_sc2268_arithmetic_ok() {
let code = "(( x = y + 1 ))";
assert_eq!(check(code).diagnostics.len(), 0);
}
#[test]
fn test_sc2268_test_ok() {
let code = "if ( test -f file ); then";
assert_eq!(check(code).diagnostics.len(), 0);
}
#[test]
fn test_sc2268_multiple_statements_ok() {
let code = "( var1=a; var2=b )";
assert_eq!(check(code).diagnostics.len(), 0);
}
}