ts-r
  • Error
  • Reported by the type checker

TS2369

A parameter property is only allowed in a constructor implementation.

A parameter property (`public x` in a parameter list) is used outside a constructor body. Move it to the constructor, or remove the modifier.

What it means

Modifiers such as public, private and readonly on parameters declare class properties, and only work on a constructor implementation. On methods, functions, constructor overloads or declarations without a body they are reported.

Example

index.ts
export class User {
  greet(private name: string) {
    return name;
  }
}
ts-r-check -p tsconfig.json --pretty false ts-r output
index.ts(2,9): error TS2369: A parameter property is only allowed in a constructor implementation.

Recorded by node scripts/verify-examples.mjs with ts-r built from commit 6deaf01. The example uses the default tsconfig: strict, target: es2022, module: esnext, moduleResolution: bundler.

How to fix

  • Remove the modifier, or move the parameter to the constructor.