oxc-project/oxc · error · OxcDiagnostic

Unexpected aliasing of members of 'this' to local variables.

Error message

Unexpected aliasing of members of 'this' to local variables.

What it means

Raised by typescript/no_this_alias when destructuring from `this` into local variables (e.g. `const { a, b } = this;`). At the throw site members of `this` are detached into locals — the plural form of the this-aliasing pattern — which snapshot mutable instance state at that instant and can desynchronize from the instance; the rule directs authors to keep member access explicit or use arrow functions. no_this_destructure_diagnostic fires from run() on destructuring declarations whose right side is `this`.

Source

Thrown at crates/oxc_linter/src/rules/typescript/no_this_alias.rs:26

use oxc_str::CompactStr;
use rustc_hash::FxHashSet;
use schemars::JsonSchema;
use serde::{Deserialize, Serialize};

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

fn no_this_alias_diagnostic(span: Span) -> OxcDiagnostic {
    OxcDiagnostic::warn("Unexpected aliasing of 'this' to local variable.")
        .with_help("Assigning a variable to this instead of properly using arrow lambdas may be a symptom of pre-ES2015 practices or not managing scope well.")
        .with_label(span)
}

fn no_this_destructure_diagnostic(span: Span) -> OxcDiagnostic {
    OxcDiagnostic::warn("Unexpected aliasing of members of 'this' to local variables.")
        .with_help(
            "Disabling destructuring of this is not a default, consider allowing destructuring",
        )
        .with_label(span)
}

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

#[derive(Debug, Clone, JsonSchema, Serialize, Deserialize)]
#[serde(rename_all = "camelCase", default, deny_unknown_fields)]
pub struct NoThisAliasConfig {
    /// Whether to allow destructuring of `this` to local variables.
    allow_destructuring: bool,
    /// An array of variable names that are allowed to alias `this`.
    #[serde(alias = "allowNames")]
    // Note: allowedNames is the config option used in the original ESLint rule, we typo'd it as allowNames.
    allowed_names: FxHashSet<CompactStr>,

View on GitHub (pinned to e1e7af627c)

Solutions

1. Access members directly through this.x instead of destructuring.
2. Enable allowDestructuring in rule options if this pattern is acceptable.

When it happens

Trigger: Thrown at crates/oxc_linter/src/rules/typescript/no_this_alias.rs:26 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/61839a66f2220a54. Report an issue: GitHub.