```ts
export function parseCsvLine(line: string): string[] {
  const fields: string[] = [];
  let currentField = '';
  let insideQuotes = false;

  for (let i = 0; i < line.length; i++) {
    const char = line[i];

    if (char === '"') {
      if (i < line.length - 1 && line[i + 1] === '"') {
        // handle escaped quote
        currentField += '"';
        i++;
      } else {
        insideQuotes = !insideQuotes;
      }
    } else if (char === ',' && !insideQuotes) {
      fields.push(currentField);
      currentField = '';
    } else {
      currentField += char;
    }
  }

  if (insideQuotes) {
    throw new Error('Unclosed quoted field');
  }

  fields.push(currentField);
  return fields;
}
```