typescript/no-unsafe-assignment Pedantic
What it does
This rule disallows assigning a value with type any to variables and properties.
Why is this bad?
The any type in TypeScript disables type checking and can lead to runtime errors. When you assign an any value to a typed variable, you're essentially bypassing TypeScript's type safety without any guarantees about the actual value.
Examples
Examples of incorrect code for this rule:
ts
declare const anyValue: any;
const str: string = anyValue; // unsafe assignment
let num: number;
num = anyValue; // unsafe assignment
const obj = {
prop: anyValue as any, // unsafe assignment
};
interface User {
name: string;
age: number;
}
const user: User = anyValue; // unsafe assignmentExamples of correct code for this rule:
ts
declare const stringValue: string;
declare const numberValue: number;
declare const unknownValue: unknown;
const str: string = stringValue; // safe
let num: number;
num = numberValue; // safe
// Use type guards with unknown
if (typeof unknownValue === "string") {
const str2: string = unknownValue; // safe after type guard
}
// Explicit any assignment (still not recommended, but intentional)
const anything: any = unknownValue;How 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-assignment": "error"
}
}ts
import { defineConfig } from "oxlint";
export default defineConfig({
options: { typeAware: true },
rules: {
"typescript/no-unsafe-assignment": "error",
},
});bash
oxlint --type-aware --deny typescript/no-unsafe-assignmentVersion
This rule was added in v1.12.0.