Domain Modeling with Abstract Classes and Protected Method Hooks

abstract class DataExporter {
  public export(data: object[]): string {
    const formatted = this.formatData(data);
    return this.wrapOutput(formatted);
  }
 
  protected abstract formatData(data: object[]): string;
 
  protected wrapOutput(content: string): string {
    return `--- START ---
${content}
--- END ---`;
  }
}
 
class CsvExporter extends DataExporter {
  protected formatData(data: object[]): string {
    return data.map(row => Object.values(row).join(",")).join("\n");
  }
}