E0243: interfaces cannot contain static blocks

static blocks in classes contain code which runs when the class is created at run time. Because TypeScript interfaces exist only at compile time, static blocks are not supported in interfaces:

class ConsoleLogger implements Logger {
  log(message) {
    console.log(message);
  }
}

let logger: Logger;
interface Logger {
  log(message: string): void;

  static {
    logger = new ConsoleLogger();
  }
}

To fix this error, move the code in the static code block outside the interface, then delete the empty static code block:

class ConsoleLogger implements Logger {
  log(message) {
    console.log(message);
  }
}

let logger: Logger;
interface Logger {
  log(message: string): void;
}
logger = new ConsoleLogger();

Introduced in quick-lint-js version 2.6.0.

Documentation for other errors