oxc-project/oxc · warning · OxcDiagnostic

Do not mix 'require' and other declarations.

Error message

Do not mix 'require' and other declarations.

What it means

Diagnostic from oxlint rule node/no-mixed-requires (style). Within a single var/let/const declaration statement, require-initialized declarators must not be mixed with plain or uninitialized ones. Node community convention keeps module-loading declarations visually separate from other initialization — the CommonJS analogue of ES module imports living apart from regular statements. This base diagnostic is emitted regardless of the rule's options; grouping/allowCall only affect the second diagnostic.

Source

Thrown at crates/oxc_linter/src/rules/node/no_mixed_requires.rs:19

use schemars::JsonSchema;
use serde::Deserialize;

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

use crate::{
    AstNode,
    context::LintContext,
    rule::{DefaultRuleConfig, Rule},
};

fn no_mix_require_diagnostic(span: Span) -> OxcDiagnostic {
    OxcDiagnostic::warn("Do not mix 'require' and other declarations.").with_label(span)
}

fn no_mix_core_module_file_computed_diagnostic(span: Span) -> OxcDiagnostic {
    OxcDiagnostic::warn("Do not mix core, module, file and computed requires.").with_label(span)
}

#[derive(Debug, Default, Clone, Copy, Deserialize, JsonSchema)]
#[serde(rename_all = "camelCase", deny_unknown_fields, default)]
struct NoMixedRequiresOptions {
    grouping: bool,
    allow_call: bool,
}

#[derive(Debug, Clone, Deserialize, JsonSchema)]
#[serde(untagged)]
enum NoMixedRequiresConfig {
    Grouping(bool),
    Options(NoMixedRequiresOptions),

View on GitHub (pinned to e1e7af627c)

Solutions

1. Split the statement: requires in their own declaration, other variables in another
2. Adopt one-declarator-per-line const/let style so mixing becomes structurally impossible
3. Note no option disables this specific check — only code restructuring (or turning the rule off) silences it

Example fix

// before
var fs = require('fs'),
    i = 0;

// after
var fs = require('fs');
var i = 0;

// .oxlintrc.json
"rules": { "node/no-mixed-requires": "error" }

npx oxlint -c .oxlintrc.json --deny-warning .

When it happens

Trigger: One VariableDeclaration whose declarators include at least one whose init is a require() call (callee is the identifier 'require'; member access like require('events').EventEmitter still counts, and with allowCall, call-chains like require('diagnostics')('x') too) AND at least one declarator that is uninitialized (var foo;) or initialized with a non-require expression. Trigger example: var fs = require('fs'), i = 0;

Common situations: ES5-era comma-chained var statements; refactors that appended a variable to an existing require line; enabling the node preset in shared configs surfaces these in old code immediately.

Related errors

• Unexpected require().
• Do not mix core, module, file and computed requires.
• Split requires to be separated into a single block.
• Unexpected access to `exports`.
• Unexpected access to `module.exports`.

AI-assisted analysis of oxc-project/oxc@e1e7af627c (2026-08-20). Data as JSON: /api/errors/cb082c892202f165. Report an issue: GitHub.