```ts
export function parseCsvLine(line: string): string[] {
  if (line === "") return [""];
  
  const result: string[] = [];
  let field = "";
  let inQuotes = false;
  
  for (let i = 0; i < line.length; i++) {
    const char = line[i];
    
    if (char === '"') {
      if (inQuotes) {
        if (i + 1 < line.length && line[i + 1] === '"') {
          field += char;
          i++; // Skip the next quote
        } else {
          inQuotes = false;
        }
      } else {
        inQuotes = true;
      }
    } else if (char === ',' && !inQuotes) {
      result.push(field.trim());
      field = "";
    } else {
      field += char;
    }
  }
  
  if (inQuotes) throw new Error("Quoted field never closed");
  
  result.push(field.trim());
  return result;
}
```