no-unsafe-assignment

Disallow assigning a value with type any to variables and properties.

✅

在 ESLint 配置中扩展"plugin:@typescript-eslint/recommended-type-checked" 可启用此规则。

💭

该规则需要类型信息才能运行，但这会带来性能方面的权衡。

TypeScript 中的 any 类型是来自类型系统的危险 "应急方案"。使用 any 会禁用许多类型检查规则，通常最好只作为最后的手段或在原型代码时使用。

¥The any type in TypeScript is a dangerous "escape hatch" from the type system. Using any disables many type checking rules and is generally best used only as a last resort or when prototyping code.

尽管你有最好的意图，但 any 类型有时会泄漏到你的代码库中。将 any 类型的值分配给变量可能很难发现，特别是如果它从外部库泄漏进来。

¥Despite your best intentions, the any type can sometimes leak into your codebase. Assigning an any typed value to a variable can be hard to pick up on, particularly if it leaks in from an external library.

此规则不允许将 any 分配给变量，并将 any[] 分配给数组解构。

¥This rule disallows assigning any to a variable, and assigning any[] to an array destructuring.

此规则还比较泛型类型参数类型，以确保你不会将通用位置中的不安全 any 传递给期望特定类型的接收者。例如，如果将 Set<any> 分配给声明为 Set<string> 的变量，则会出错。

¥This rule also compares generic type argument types to ensure you don't pass an unsafe any in a generic position to a receiver that's expecting a specific type. For example, it will error if you assign Set<any> to a variable declared as Set<string>.

Flat Config
Legacy Config

eslint.config.mjs
export default tseslint.config({
  rules: {
    "@typescript-eslint/no-unsafe-assignment": "error"
  }
});

.eslintrc.cjs
module.exports = {
  "rules": {
    "@typescript-eslint/no-unsafe-assignment": "error"
  }
};

在线运行试试这个规则 ↗

示例

¥Examples

❌ Incorrect
✅ Correct

const x = 1 as any,
  y = 1 as any;
const [x] = 1 as any;
const [x] = [] as any[];
const [x] = [1 as any];
[x] = [1] as [any];

function foo(a = 1 as any) {}
class Foo {
  constructor(private a = 1 as any) {}
}
class Foo {
  private a = 1 as any;
}

// generic position examples
const x: Set<string> = new Set<any>();
const x: Map<string, string> = new Map<string, any>();
const x: Set<string[]> = new Set<any[]>();
const x: Set<Set<Set<string>>> = new Set<Set<Set<any>>>();
Open in Playground

const x = 1,
  y = 1;
const [x] = [1];
[x] = [1] as [number];

function foo(a = 1) {}
class Foo {
  constructor(private a = 1) {}
}
class Foo {
  private a = 1;
}

// generic position examples
const x: Set<string> = new Set<string>();
const x: Map<string, string> = new Map<string, string>();
const x: Set<string[]> = new Set<string[]>();
const x: Set<Set<Set<string>>> = new Set<Set<Set<string>>>();
Open in Playground

有些情况下规则允许将 any 分配给 unknown。

¥There are cases where the rule allows assignment of any to unknown.

允许的 any 到 unknown 分配示例：

¥Example of any to unknown assignment that are allowed:

const x: unknown = y as any;
const x: unknown[] = y as any[];
const x: Set<unknown> = y as Set<any>;
Open in Playground

选项

该规则不可配置。

何时不使用它

¥When Not To Use It

如果你的代码库有许多现有的 any 或不安全代码区域，则可能很难启用此规则。在项目不安全区域中增加类型安全性时，跳过 no-unsafe-* 规则可能会更容易。你可以考虑在这些特定情况下使用 ESLint 禁用注释，而不是完全禁用此规则。

¥If your codebase has many existing anys or areas of unsafe code, it may be difficult to enable this rule. It may be easier to skip the no-unsafe-* rules pending increasing type safety in unsafe areas of your project. You might consider using ESLint disable comments for those specific situations instead of completely disabling this rule.

示例​

选项​

何时不使用它​

相关​

示例

选项

何时不使用它

相关