ts-r
  • Error
  • Reported by the type checker

TS2387

Function overload must be static.

Overloads of a class method mix static and instance signatures. Make every overload of the member static, or none of them.

What it means

Overloads and their implementation must all live on the same side of the class. When the first signature for a name is static, a later signature or implementation without static is reported.

Example

index.ts
export class Ids {
  static next(prefix: string): string;
  next(prefix: string): string {
    return prefix + "1";
  }
}
ts-r-check -p tsconfig.json --pretty false ts-r output
index.ts(3,3): error TS2387: Function overload must be static.

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

  • Make every overload and the implementation static.
  • If you need both an instance and a static method, give them different names.