typescript/no-unsafe-unary-minus Correctness
What it does
This rule disallows using the unary minus operator on a value which is not of type 'number' | 'bigint'.
Why is this bad?
The unary minus operator should only be used on numeric values. Using it on other types can lead to unexpected behavior due to JavaScript's type coercion rules.
Examples
Examples of incorrect code for this rule:
ts
declare const value: any;
const result1 = -value; // unsafe on any
declare const str: string;
const result2 = -str; // unsafe on string
declare const bool: boolean;
const result3 = -bool; // unsafe on boolean
declare const obj: object;
const result4 = -obj; // unsafe on object
declare const arr: any[];
const result5 = -arr; // unsafe on arrayExamples of correct code for this rule:
ts
declare const num: number;
const result1 = -num; // safe
declare const bigint: bigint;
const result2 = -bigint; // safe
const literal = -42; // safe
const bigintLiteral = -42n; // safe
declare const union: number | bigint;
const result3 = -union; // safe
// Convert to number first if needed
declare const str: string;
const result4 = -Number(str); // safe conversionHow to use
To enable this rule using the config file or in the CLI, you can use:
json
{
"options": {
"typeAware": true
},
"rules": {
"typescript/no-unsafe-unary-minus": "error"
}
}ts
import { defineConfig } from "oxlint";
export default defineConfig({
options: { typeAware: true },
rules: {
"typescript/no-unsafe-unary-minus": "error",
},
});bash
oxlint --type-aware --deny typescript/no-unsafe-unary-minusVersion
This rule was added in v1.12.0.