use crate::linter::{Diagnostic, LintResult, Severity, Span};
use regex::Regex;
static ARITHMETIC_SHORTCUT: std::sync::LazyLock<Regex> = std::sync::LazyLock::new(|| {
Regex::new(r"\w+\s*=\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 line.contains("$((") || line.contains("((") {
continue;
}
if ARITHMETIC_SHORTCUT.is_match(line) {
let diagnostic = Diagnostic::new(
"SC2210",
Severity::Error,
"Prefix operators (++/--) only work in arithmetic context. Use x=$((y + 1))"
.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_sc2210_prefix_increment() {
let code = r#"x=++y"#;
let result = check(code);
assert_eq!(result.diagnostics.len(), 1);
}
#[test]
fn test_sc2210_prefix_decrement() {
let code = r#"count=--total"#;
let result = check(code);
assert_eq!(result.diagnostics.len(), 1);
}
#[test]
fn test_sc2210_arithmetic_context_ok() {
let code = r#"x=$((++y))"#;
let result = check(code);
assert_eq!(result.diagnostics.len(), 0);
}
#[test]
fn test_sc2210_double_paren_ok() {
let code = r#"((x=++y))"#;
let result = check(code);
assert_eq!(result.diagnostics.len(), 0);
}
#[test]
fn test_sc2210_normal_assignment_ok() {
let code = r#"x=$y"#;
let result = check(code);
assert_eq!(result.diagnostics.len(), 0);
}
#[test]
fn test_sc2210_addition_ok() {
let code = r#"x=$((y + 1))"#;
let result = check(code);
assert_eq!(result.diagnostics.len(), 0);
}
#[test]
fn test_sc2210_spaces() {
let code = r#"val = ++count"#;
let result = check(code);
assert_eq!(result.diagnostics.len(), 1);
}
#[test]
fn test_sc2210_comment_skipped() {
let code = r#"# x=++y"#;
let result = check(code);
assert_eq!(result.diagnostics.len(), 0);
}
#[test]
fn test_sc2210_string_literal_ok() {
let code = r#"text="++value""#;
let result = check(code);
assert_eq!(result.diagnostics.len(), 0); }
#[test]
fn test_sc2210_underscore_var() {
let code = r#"_new=++_old"#;
let result = check(code);
assert_eq!(result.diagnostics.len(), 1);
}
}