use crate::linter::{Diagnostic, LintResult, Severity, Span};
use regex::Regex;
static DOLLAR_IN_ARITHMETIC: std::sync::LazyLock<Regex> = std::sync::LazyLock::new(|| {
Regex::new(r"\(\(\s*\$\w+").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 DOLLAR_IN_ARITHMETIC.is_match(line) {
let diagnostic = Diagnostic::new(
"SC2245",
Severity::Info,
"$ is unnecessary in arithmetic contexts: use (( var )) instead of (( $var ))"
.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_sc2245_dollar_in_arithmetic() {
let code = "(( $count + 1 ))";
let result = check(code);
assert_eq!(result.diagnostics.len(), 1);
}
#[test]
fn test_sc2245_no_dollar_ok() {
let code = "(( count + 1 ))";
let result = check(code);
assert_eq!(result.diagnostics.len(), 0);
}
#[test]
fn test_sc2245_dollar_cmdsub() {
let code = "result=$(( $a + $b ))";
let result = check(code);
assert_eq!(result.diagnostics.len(), 1);
}
#[test]
fn test_sc2245_no_dollar_cmdsub_ok() {
let code = "result=$(( a + b ))";
let result = check(code);
assert_eq!(result.diagnostics.len(), 0);
}
#[test]
fn test_sc2245_comment_skipped() {
let code = "# (( $var ))";
let result = check(code);
assert_eq!(result.diagnostics.len(), 0);
}
#[test]
fn test_sc2245_increment() {
let code = "(( $i++ ))";
let result = check(code);
assert_eq!(result.diagnostics.len(), 1);
}
#[test]
fn test_sc2245_assignment() {
let code = "(( $x = 5 ))";
let result = check(code);
assert_eq!(result.diagnostics.len(), 1);
}
#[test]
fn test_sc2245_no_code() {
let code = "";
let result = check(code);
assert_eq!(result.diagnostics.len(), 0);
}
#[test]
fn test_sc2245_normal_command() {
let code = "echo test";
let result = check(code);
assert_eq!(result.diagnostics.len(), 0);
}
#[test]
fn test_sc2245_complex_expr() {
let code = "(( $a * $b + $c ))";
let result = check(code);
assert_eq!(result.diagnostics.len(), 1); }
}