oxc-project/oxc · warning

Unexpected empty static blocks

Error message

Unexpected empty static blocks

What it means

This diagnostic comes from the `no_empty_static_block` rule in oxlint. It reports a class static initialization block (`static { ... }`, ES2022) that contains no statements. An empty static block has no effect, so it is dead code left by mistake. The report carries a label on the block span.

Source

Thrown at crates/oxc_linter/src/rules/eslint/no_empty_static_block.rs:9

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

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

fn no_empty_static_block_diagnostic(span: Span) -> OxcDiagnostic {
    OxcDiagnostic::warn("Unexpected empty static blocks")
        .with_help("Remove this empty block or add content to it.")
        .with_label(span)
}

#[derive(Debug, Default, Clone)]
pub struct NoEmptyStaticBlock;

declare_oxc_lint!(
    /// ### What it does
    ///
    /// Disallow empty static blocks.
    ///
    /// ### Why is this bad?
    ///
    /// Empty block statements, while not technically errors, usually occur due
    /// to refactoring that wasn’t completed.  They can cause confusion when
    /// reading code.
    ///

View on GitHub (pinned to e1e7af627c)

Solutions

1. Remove the empty `static {}` block.
2. Move the intended initialization into it, or use static field initializers.
3. Suppress in generated code with `// oxlint-disable-next-line no-empty-static-block`.

Example fix

// before
class Registry {
  static {}
  static items = [];
}

// after
class Registry {
  static items = [];
}

// find empty static blocks before lint
if (/static\s*{\s*}/.test(src)) throw new Error('empty static block');

When it happens

Trigger: A class that contains `class A { static {} }`. The rule matches static block nodes during traversal and reports each one with an empty body.

Common situations: A static block was planned for class-level setup, then the setup moved to the constructor or to module scope. Generated code emits the block without condition.

Related errors

• Duplicate class member: {member_name:?}
• `debugger` statement is not allowed
• Variables should not be deleted
• A regular expression literal can be confused with '/='.
• Duplicate conditions in if-else-if chain

AI-assisted analysis of oxc-project/oxc@e1e7af627c (2026-08-20). Data as JSON: /api/errors/d978a31ba3b00dfe. Report an issue: GitHub.