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react_auditor/rules/react/
no_set_state_in_render.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 NoSetStateInRender;
8
9const RULE_META: RuleMeta = RuleMeta {
10    id: "no-set-state-in-render",
11    default_severity: Severity::Error,
12    category: "react",
13    description: "No setState calls directly in render body",
14};
15
16impl Rule for NoSetStateInRender {
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 = SetStateInRenderCollector {
23            findings: Vec::new(),
24            source: source_text,
25            in_effect: false,
26        };
27        collector.visit_program(program);
28        collector.findings
29    }
30}
31
32struct SetStateInRenderCollector<'a> {
33    findings: Vec<RuleFinding>,
34    source: &'a str,
35    in_effect: bool,
36}
37
38impl<'a> SetStateInRenderCollector<'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 is_state_setter(&self, name: &str) -> bool {
50        name.starts_with("set") && name.len() > 3 && name.as_bytes()[3].is_ascii_uppercase()
51    }
52}
53
54impl<'a> Visit<'a> for SetStateInRenderCollector<'a> {
55    fn visit_call_expression(&mut self, expr: &oxc_ast::ast::CallExpression<'a>) {
56        let name = if let oxc_ast::ast::Expression::Identifier(ident) = &expr.callee {
57            ident.name.as_str()
58        } else {
59            return;
60        };
61
62        if name == "useEffect" || name == "useLayoutEffect" {
63            let was = self.in_effect;
64            self.in_effect = true;
65            oxc_ast_visit::walk::walk_call_expression(self, expr);
66            self.in_effect = was;
67            return;
68        }
69
70        if !self.in_effect && self.is_state_setter(name) {
71            self.add_finding(
72                expr.span.start as usize,
73                format!("`{name}` called during render — causes re-render loop"),
74            );
75        }
76    }
77}