react_auditor/rules/performance/
prefer_fragments.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 PreferFragments;
8
9const RULE_META: RuleMeta = RuleMeta {
10    id: "prefer-fragments",
11    default_severity: Severity::Warning,
12    category: "performance",
13    description: "Use `<></>` over unnecessary wrapper divs",
14};
15
16impl Rule for PreferFragments {
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 = FragmentCollector {
23            findings: Vec::new(),
24            source: source_text,
25        };
26        collector.visit_program(program);
27        collector.findings
28    }
29}
30
31struct FragmentCollector<'a> {
32    findings: Vec<RuleFinding>,
33    source: &'a str,
34}
35
36impl<'a> Visit<'a> for FragmentCollector<'a> {
37    fn visit_jsx_opening_element(&mut self, el: &oxc_ast::ast::JSXOpeningElement<'a>) {
38        let is_div = matches!(&el.name, oxc_ast::ast::JSXElementName::Identifier(id) if id.name.as_str() == "div");
39        if !is_div {
40            return;
41        }
42        let has_class = el.attributes.iter().any(|attr| {
43            if let oxc_ast::ast::JSXAttributeItem::Attribute(a) = attr {
44                matches!(&a.name, oxc_ast::ast::JSXAttributeName::Identifier(id) if id.name.as_str() == "className" || id.name.as_str() == "class")
45            } else {
46                false
47            }
48        });
49        if has_class {
50            return;
51        }
52        let has_style = el.attributes.iter().any(|attr| {
53            if let oxc_ast::ast::JSXAttributeItem::Attribute(a) = attr {
54                matches!(&a.name, oxc_ast::ast::JSXAttributeName::Identifier(id) if id.name.as_str() == "style")
55            } else {
56                false
57            }
58        });
59        if !has_class && !has_style {
60            let start = el.span.start as usize;
61            let line = self.source[..start].lines().count().max(1);
62            let col = start - self.source[..start].rfind('\n').map(|i| i + 1).unwrap_or(0);
63            self.findings.push(RuleFinding {
64                line,
65                column: col + 1,
66                message: "Unnecessary `<div>` wrapper — use `<></>` Fragment instead".to_string(),
67            });
68        }
69    }
70}
react_auditor/rules/performance/prefer_fragments.rs

react_auditor/rules/performance/
prefer_fragments.rs
