oxc-project/oxc · error · OxcDiagnostic

`defineEmits` has been called multiple times.

Error message

`defineEmits` has been called multiple times.

What it means

Emitted by run_once of the vue valid-define-emits rule when the defineEmits macro is invoked more than once in the same <script setup> block. The compiler only supports one declaration; both call sites are labeled in the diagnostic.

Source

Thrown at crates/oxc_linter/src/rules/vue/valid_define_emits.rs:20

use oxc_diagnostics::OxcDiagnostic;
use oxc_macros::declare_oxc_lint;
use oxc_span::Span;

use crate::{
    context::LintContext,
    frameworks::FrameworkOptions,
    rule::Rule,
    utils::{DefineMacroProblem, check_define_macro_call_expression, has_default_exports_property},
};

fn has_type_and_arguments_diagnostic(span: Span) -> OxcDiagnostic {
    OxcDiagnostic::warn("`defineEmits` has both a type-only emit and an argument.")
        .with_help("remove the argument for better type inference.")
        .with_label(span)
}

fn called_multiple_times(span: Span, second_span: Span) -> OxcDiagnostic {
    OxcDiagnostic::warn("`defineEmits` has been called multiple times.")
        .with_help("combine all events into a single `defineEmits` call.")
        .with_labels([
            span.label("`defineEmits` is called here"),
            second_span.label("`defineEmits` is called here too"),
        ])
}

fn events_not_defined(span: Span) -> OxcDiagnostic {
    OxcDiagnostic::warn("Custom events are not defined.")
        .with_help("Define at least one event in `defineEmits`.")
        .with_label(span)
}

fn referencing_locally(span: Span) -> OxcDiagnostic {
    OxcDiagnostic::warn("`defineEmits` is referencing locally declared variables.")
        .with_help("inline the variable or import it from another module.")
        .with_label(span)
}

View on GitHub (pinned to e1e7af627c)

Solutions

1. Merge all events into a single defineEmits call, e.g. defineEmits(['change', 'input']) or one combined type literal

When it happens

Trigger: Thrown at crates/oxc_linter/src/rules/vue/valid_define_emits.rs:20 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/52b6f371aa030b55. Report an issue: GitHub.