use crate::linter::{Diagnostic, LintResult, Severity, Span};
use regex::Regex;
static EXPR_LENGTH: std::sync::LazyLock<Regex> =
std::sync::LazyLock::new(|| Regex::new(r"expr\s+length\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 EXPR_LENGTH.is_match(line) {
let diagnostic = Diagnostic::new(
"SC2289",
Severity::Info,
"Use ${#var} instead of expr length for string length".to_string(),
Span::new(line_num, 1, line_num, line.len() + 1),
);
result.add(diagnostic);
}
}
result
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_sc2289_expr_length() {
let code = "len=$(expr length $str)";
assert_eq!(check(code).diagnostics.len(), 1);
}
#[test]
fn test_sc2289_param_expansion_ok() {
let code = "len=${#str}";
assert_eq!(check(code).diagnostics.len(), 0);
}
#[test]
fn test_sc2289_comment() {
let code = "# expr length $var";
assert_eq!(check(code).diagnostics.len(), 0);
}
#[test]
fn test_sc2289_empty() {
assert_eq!(check("").diagnostics.len(), 0);
}
#[test]
fn test_sc2289_normal() {
assert_eq!(check("echo test").diagnostics.len(), 0);
}
#[test]
fn test_sc2289_expr_arithmetic_ok() {
let code = "expr 1 + 1";
assert_eq!(check(code).diagnostics.len(), 0);
}
#[test]
fn test_sc2289_expr_substr_ok() {
let code = "expr substr $str 1 5";
assert_eq!(check(code).diagnostics.len(), 0);
}
#[test]
fn test_sc2289_wc_ok() {
let code = "wc -c <<< $str";
assert_eq!(check(code).diagnostics.len(), 0);
}
#[test]
fn test_sc2289_braced_var() {
let code = "expr length ${var}";
assert_eq!(check(code).diagnostics.len(), 1);
}
#[test]
fn test_sc2289_awk_ok() {
let code = r#"awk '{print length}' <<< $str"#;
assert_eq!(check(code).diagnostics.len(), 0);
}
}