#parameter-properties

#Configuration

import { defineConfig, ts } from '@rslint/core';

export default defineConfig([
  ts.configs.recommended,
  {
    rules: {
      '@typescript-eslint/parameter-properties': 'error',
    },
  },
]);

#Rule Details

Require or disallow parameter properties in class constructors.

TypeScript includes a shorthand for declaring and initializing class members from constructor parameters called parameter properties. This rule can be used to enforce consistent usage of this feature.

#Options

• prefer ("class-property" | "parameter-property"): Whether to prefer class properties or parameter properties. Default: "class-property".
• allow (array of modifiers): Which parameter property modifiers to allow. Valid values: "readonly", "private", "protected", "public", "private readonly", "protected readonly", "public readonly". Default: [].

#prefer: "class-property" (default)

Examples of incorrect code:

class Foo {
  constructor(readonly name: string) {}
}

class Bar {
  constructor(private age: number) {}
}

Examples of correct code:

class Foo {
  constructor(name: string) {}
}

#prefer: "parameter-property"

Examples of incorrect code:

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

Examples of correct code:

class Foo {
  constructor(private member: string) {}
}

#Original Documentation

https://typescript-eslint.io/rules/parameter-properties