no-unnecessary-parameter-property-assignment

Disallow unnecessary assignment of constructor property parameter.

TypeScript's parameter properties allow creating and initializing a member in one place. Therefore, in most cases, it is not necessary to assign parameter properties of the same name to members within a constructor.

Flat Config

eslint.config.mjs

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

Legacy Config

.eslintrc.cjs

module.exports = {
  "rules": {
    "@typescript-eslint/no-unnecessary-parameter-property-assignment": "error"
  }
};

Try this rule in the playground ↗

Examples

❌ Incorrect

class Foo {
  constructor(public bar: string) {
    this.bar = bar;
  }
}

Open in Playground

✅ Correct

class Foo {
  constructor(public bar: string) {}
}

Open in Playground

Options

This rule is not configurable.

When Not To Use It

If you don't use parameter properties, you can ignore this rule.

Resources

• Rule source
• Test source