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。

TypeScript 中的 any 类型是类型系统中危险的 "应急方案"。使用 any 会禁用许多类型检查规则，通常最好仅作为最后手段或在构建代码原型时使用。

英：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.

尽管你的意图是好的，但 any 类型有时可能会泄漏到你的代码库中。将 any 类型值分配给变量可能很难理解，特别是当它从外部库泄漏时。

英：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。

英：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，以确保你不会将泛型位置中的不安全 any 传递给需要特定类型的接收者。例如，如果将 Set<any> 分配给声明为 Set<string> 的变量，则会出错。

英：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>.

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

在线运行试试这个规则 ↗

示例

❌ 不正确
✅ 正确

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

在某些情况下，规则允许将 any 分配给 unknown。

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

允许的 any 到 unknown 分配示例：

英：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

何时不使用它

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。在项目的不安全区域中，在增加类型安全性之前，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。

英：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.

选项

该规则不可配置。

示例​

何时不使用它​

相关​

选项​

资源​

示例

何时不使用它

相关

选项

资源