use crate::linter::{Diagnostic, LintResult, Severity, Span};
use regex::Regex;
static LET_SIMPLE: std::sync::LazyLock<Regex> = std::sync::LazyLock::new(|| {
Regex::new(r"\blet\s+[a-zA-Z_][a-zA-Z0-9_]*=[a-zA-Z0-9_+\-*/]+\b").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 LET_SIMPLE.is_match(line) {
let diagnostic = Diagnostic::new(
"SC2294",
Severity::Info,
"Use ((...)) instead of let for simple arithmetic 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_sc2294_let_assign() {
let code = "let x=5";
assert_eq!(check(code).diagnostics.len(), 1);
}
#[test]
fn test_sc2294_double_paren_ok() {
let code = "(( x = 5 ))";
assert_eq!(check(code).diagnostics.len(), 0);
}
#[test]
fn test_sc2294_let_arithmetic() {
let code = "let count=count+1";
assert_eq!(check(code).diagnostics.len(), 1);
}
#[test]
fn test_sc2294_comment() {
let code = "# let x=5";
assert_eq!(check(code).diagnostics.len(), 0);
}
#[test]
fn test_sc2294_empty() {
assert_eq!(check("").diagnostics.len(), 0);
}
#[test]
fn test_sc2294_normal() {
assert_eq!(check("echo test").diagnostics.len(), 0);
}
#[test]
fn test_sc2294_dollar_arithmetic_ok() {
let code = "x=$(( y + 1 ))";
assert_eq!(check(code).diagnostics.len(), 0);
}
#[test]
fn test_sc2294_expr_ok() {
let code = "x=$(expr 1 + 1)";
assert_eq!(check(code).diagnostics.len(), 0);
}
#[test]
fn test_sc2294_string_let_ok() {
let code = r#"let "x = y + 1""#;
assert_eq!(check(code).diagnostics.len(), 0);
}
#[test]
fn test_sc2294_increment() {
let code = "let i=i+1";
assert_eq!(check(code).diagnostics.len(), 1);
}
}