react_auditor/rules/react/
prefer_function_components.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 PreferFunctionComponents;
8
9const RULE_META: RuleMeta = RuleMeta {
10    id: "prefer-function-components",
11    default_severity: Severity::Warning,
12    category: "react",
13    description: "Prefer function components over class components",
14};
15
16impl Rule for PreferFunctionComponents {
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 = ClassComponentCollector {
23            findings: Vec::new(),
24            source: source_text,
25        };
26        collector.visit_program(program);
27        collector.findings
28    }
29}
30
31struct ClassComponentCollector<'a> {
32    findings: Vec<RuleFinding>,
33    source: &'a str,
34}
35
36impl<'a> Visit<'a> for ClassComponentCollector<'a> {
37    fn visit_class(&mut self, class: &oxc_ast::ast::Class<'a>) {
38        let extends_react = class.super_class.as_ref().is_some_and(|expr| {
39            if let oxc_ast::ast::Expression::Identifier(ident) = expr {
40                let name = ident.name.as_str();
41                name == "Component" || name == "PureComponent"
42            } else if let Some(member) = expr.as_member_expression() {
43                member
44                    .static_property_name()
45                    .is_some_and(|n| n == "Component" || n == "PureComponent")
46            } else {
47                false
48            }
49        });
50
51        if extends_react && let Some(id) = &class.id {
52            let start = id.span.start as usize;
53            let line = self.source[..start].lines().count().max(1);
54            let col = start - self.source[..start].rfind('\n').map(|i| i + 1).unwrap_or(0);
55            self.findings.push(RuleFinding {
56                line,
57                column: col + 1,
58                message: format!(
59                    "`{}` extends Component — prefer a function component",
60                    id.name
61                ),
62            });
63        }
64    }
65}
react_auditor/rules/react/prefer_function_components.rs

react_auditor/rules/react/
prefer_function_components.rs
