react_auditor/rules/performance/
heading_levels.rs

1use oxc_ast::ast::Program;
2use oxc_ast_visit::Visit;
3use oxc_semantic::Semantic;
4
5use crate::rules::{Rule, RuleFinding, RuleMeta, Severity};
6
7pub struct HeadingLevels;
8
9const RULE_META: RuleMeta = RuleMeta {
10    id: "heading-levels",
11    default_severity: Severity::Warning,
12    category: "accessibility",
13    description: "Heading levels should not be skipped",
14};
15
16impl Rule for HeadingLevels {
17    fn meta(&self) -> &RuleMeta {
18        &RULE_META
19    }
20
21    fn run(&self, program: &Program, _semantic: &Semantic, source_text: &str) -> Vec<RuleFinding> {
22        let mut collector = HeadingCollector {
23            findings: Vec::new(),
24            source: source_text,
25            prev_level: 0,
26        };
27        collector.visit_program(program);
28        collector.findings
29    }
30}
31
32struct HeadingCollector<'a> {
33    findings: Vec<RuleFinding>,
34    source: &'a str,
35    prev_level: u8,
36}
37
38impl<'a> HeadingCollector<'a> {
39    fn add_finding(&mut self, start: usize, msg: String) {
40        let line = self.source[..start].lines().count().max(1);
41        let col = start - self.source[..start].rfind('\n').map(|i| i + 1).unwrap_or(0);
42        self.findings.push(RuleFinding {
43            line,
44            column: col + 1,
45            message: msg,
46        });
47    }
48
49    fn parse_heading(el: &oxc_ast::ast::JSXOpeningElement) -> Option<u8> {
50        if let oxc_ast::ast::JSXElementName::Identifier(id) = &el.name {
51            let name = id.name.as_str();
52            if name.len() == 2 && name.starts_with('h') {
53                let n = name.as_bytes()[1].wrapping_sub(b'0');
54                if (1..=6).contains(&n) {
55                    return Some(n);
56                }
57            }
58        }
59        None
60    }
61}
62
63impl<'a> Visit<'a> for HeadingCollector<'a> {
64    fn visit_jsx_opening_element(&mut self, el: &oxc_ast::ast::JSXOpeningElement<'a>) {
65        let Some(level) = Self::parse_heading(el) else {
66            return;
67        };
68
69        if self.prev_level > 0 && level > self.prev_level + 1 {
70            self.add_finding(
71                el.span.start as usize,
72                format!(
73                    "Heading level skipped: h{} followed by h{}",
74                    self.prev_level, level
75                ),
76            );
77        }
78        self.prev_level = level;
79    }
80}
react_auditor/rules/performance/heading_levels.rs

react_auditor/rules/performance/
heading_levels.rs
