oxc-project/oxc · warning · OxcDiagnostic

Identifier name is too short (< {config_min}).

Error message

Identifier name is too short (< {config_min}).

What it means

Reported by the `id-length` rule (ESLint id-length port) when an identifier's name has fewer characters than the configured (or default) minimum. The default configuration in oxc sets `min: 2` and `max: u64::MAX` (crates/oxc_linter/src/rules/eslint/id_length.rs:32-33), so with defaults only single-character names are flagged. It is a style rule aimed at self-documenting names.

Source

Thrown at crates/oxc_linter/src/rules/eslint/id_length.rs:25

use unicode_segmentation::UnicodeSegmentation;

use oxc_ast::AstKind;
use oxc_ast::ast::{
    BindingIdentifier, BindingPattern, BindingProperty, IdentifierName, PrivateIdentifier,
};
use oxc_diagnostics::OxcDiagnostic;
use oxc_macros::declare_oxc_lint;
use oxc_span::{ContentEq, GetSpan, Span};

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

fn id_length_is_too_short_diagnostic(span: Span, config_min: u64) -> OxcDiagnostic {
    OxcDiagnostic::warn(format!("Identifier name is too short (< {config_min}).")).with_label(span)
}

fn id_length_is_too_long_diagnostic(span: Span, config_max: u64) -> OxcDiagnostic {
    OxcDiagnostic::warn(format!("Identifier name is too long (> {config_max}).")).with_label(span)
}

const DEFAULT_MAX_LENGTH: u64 = u64::MAX;
const DEFAULT_MIN_LENGTH: u64 = 2;

#[derive(Debug, Clone, Default, Deserialize)]
pub struct IdLength(Box<IdLengthConfig>);

impl Deref for IdLength {
    type Target = IdLengthConfig;

    fn deref(&self) -> &Self::Target {
        &self.0
    }

View on GitHub (pinned to 5b3e335484)

Solutions

1. Rename short identifiers to descriptive ones (`x` → `offsetX`, `i` → `rowIndex`) — the primary intent of the rule.
2. Add conventional short names to the rule's exceptions: `{ "id-length": ["error", { "min": 2, "exceptions": ["x", "y", "_"] }] }` (oxlint supports exceptions/exceptionPatterns like ESLint).
3. Lower `min` (e.g. to 1) or disable the rule if the codebase convention accepts single-character names in loops.

Example fix

// before
users.forEach((u, i) => rows[i] = renderRow(u));

// after
users.forEach((user, rowIndex) => rows[rowIndex] = renderRow(user));

// Encode your real convention once:
// .oxlintrc.json -> "id-length": ["error", { "min": 2, "exceptions": ["i", "j", "x", "y", "_"] }]
// oxlint runs in CI and fails before short names land.

When it happens

Trigger: Declare or use identifiers of length < min: `let x = 1;`, `for (let i = 0; ...)` with the default min of 2, `const e = new Error()`; or raise the minimum via config `{ "id-length": ["error", { "min": 4 }] }` and keep short names like `err`. The check applies to variable, function, class, and parameter names (with exceptions options available).

Common situations: Enabling id-length in an existing repo where loop counters `i`, `j`, `k` and error variable `e` are everywhere; raising `min` beyond the team's actual habits; catching that `exceptions`/`exceptionPatterns` need entries for conventional short names (`x`/`y` in geometry code, `id`, `db`); refactoring generated or math-heavy code full of short symbols.

Related errors

• Identifier '{name}' is restricted.
• Identifier '#{name}' is restricted.
• A constructor name should not start with a lowercase letter.
• A function with a name starting with an uppercase letter sho
• `VirtualFree` failed during cleanup: {err}

AI-assisted analysis of oxc-project/oxc@5b3e335484 (2026-08-20). Data as JSON: /api/errors/02abbb848b2f8836. Report an issue: GitHub.