oxc-project/oxc · error · OxcDiagnostic

Function component is not {article} {}

Error message

Function component is not {article} {}

What it means

Raised by react/function-component-definition when a function component's declaration style does not match the configured allowed styles (e.g. the rule is set to arrow functions but the component is a function declaration). The article is 'an' for arrow, 'a' otherwise.

Source

Thrown at crates/oxc_linter/src/rules/react/function_component_definition.rs:22

use oxc_ast::{
    AstKind,
    ast::{AssignmentTarget, FunctionType, VariableDeclarator},
};
use oxc_diagnostics::OxcDiagnostic;
use oxc_macros::declare_oxc_lint;
use oxc_span::{GetSpan, Span};

use crate::{
    AstNode,
    ast_util::iter_outer_expressions,
    context::LintContext,
    rule::{DefaultRuleConfig, Rule},
    utils::{arrow_function_returns, function_returns, is_hoc_call, is_react_component_name},
};

fn function_component_definition_diagnostic(span: Span, expected: FunctionStyle) -> OxcDiagnostic {
    let article = if expected == FunctionStyle::Arrow { "an" } else { "a" };
    OxcDiagnostic::warn(format!("Function component is not {article} {}", expected.description()))
        .with_label(span)
}

#[derive(Debug, Default, Clone, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "camelCase", default, deny_unknown_fields)]
struct FunctionComponentDefinitionConfig {
    named_components: NamedComponents,
    unnamed_components: UnnamedComponents,
}

#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema)]
#[serde(untagged)]
enum NamedComponents {
    Single(NamedComponentStyle),
    Multiple(Vec<NamedComponentStyle>),
}

impl Default for NamedComponents {

View on GitHub (pinned to e1e7af627c)

Solutions

1. Rewrite the component in the style required by the rule configuration (arrow function, named function, or function expression).
2. Adjust the allowedStyles/namedComponents setting to permit the current style.

When it happens

Trigger: Thrown at crates/oxc_linter/src/rules/react/function_component_definition.rs:22 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of oxc-project/oxc@e1e7af627c (2026-08-20). Data as JSON: /api/errors/23e5923239fc168a. Report an issue: GitHub.