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Rslint

    no-unnecessary-parameter-property-assignment

    Configuration

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

export default defineConfig([
  ts.configs.recommended,
  {
    rules: {
      '@typescript-eslint/no-unnecessary-parameter-property-assignment': 'error',
    },
  },
]);

    Rule Details

    Disallow unnecessary assignment of constructor property parameter.

    TypeScript's parameter property syntax (constructor(public foo: string)) both declares a class member and assigns the constructor argument to it. Writing an explicit this.foo = foo inside the constructor body therefore performs the exact same assignment a second time and adds nothing. This rule reports this.X = X — and the ||=, &&=, ??= variants that have the same effect on a freshly-bound member — when the constructor's parameter list declares a parameter property named X.

    Examples of incorrect code for this rule:

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

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

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

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

class Foo {
  constructor(private foo: string) {
    this['foo'] = foo;
  }
}

class Foo {
  constructor(public foo?: string) {
    this.foo = foo!;
  }
}

class Foo {
  constructor(public foo?: string) {
    this.foo = foo as any;
  }
}

    Examples of correct code for this rule:

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

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

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

class Foo {
  constructor(public foo: number) {
    this.foo += foo;
    this.foo -= foo;
  }
}

class Foo {
  constructor(public foo: number) {
    this.foo += 1;
    this.foo = foo;
  }
}

class Foo {
  constructor(public foo: number) {
    {
      const foo = 1;
      this.foo = foo;
    }
  }
}

    Original Documentation