```ts
/**
 * Splits one line of CSV into its fields on commas.
 *
 * A field wrapped in double quotes may contain commas, and a doubled quote inside such a field means one literal quote character;
 * the surrounding quotes are not part of the value. Fields that are not quoted are taken literally, including any surrounding spaces.
 * An empty line is considered an empty field.
 */
export function parseCsvLine(line: string): string[] {
    const fields = [];

    let currentField = '';
    let inQuotes = false;

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

        if (char === '"') {
            if (currentField) {
                throw new Error(`Unbalanced quotes: "${line}"`);
            }
            inQuotes = !inQuotes;
            currentField += char;
        } else if (!inQuotes && char === ',') {
            fields.push(currentField.trim());
            currentField = '';
        } else {
            currentField += char;
        }
    }

    if (currentField) {
        fields.push(currentField.trim());
    }

    return fields;
}
```