no-unsafe-member-access.md

no-unsafe-member-access

Disallows member access on any typed variables.

Despite your best intentions, the any type can sometimes leak into your codebase. Member access on any typed variables is not checked at all by TypeScript, so it creates a potential safety hole, and source of bugs in your codebase.

Rule Details

This rule disallows member access on any variable that is typed as any.

Examples of code for this rule:

❌ Incorrect

declare const anyVar: any;
declare const nestedAny: { prop: any };

anyVar.a;
anyVar.a.b;
anyVar['a'];
anyVar['a']['b'];

nestedAny.prop.a;
nestedAny.prop['a'];

const key = 'a';
nestedAny.prop[key];

// Using an any to access a member is unsafe
const arr = [1, 2, 3];
arr[anyVar];
nestedAny[anyVar];

✅ Correct

declare const properlyTyped: { prop: { a: string } };

properlyTyped.prop.a;
properlyTyped.prop['a'];

const key = 'a';
properlyTyped.prop[key];

const arr = [1, 2, 3];
arr[1];
const idx = 1;
arr[idx];
arr[idx++];

Options

// .eslintrc.json
{
  "rules": {
    "@typescript-eslint/no-unsafe-member-access": "error"
  }
}

This rule is not configurable.

Related To

• no-explicit-any
• TSLint: no-unsafe-any

Attributes

• ✅ Recommended
• 🔧 Fixable
• 💭 Requires type information