```typescript
/** The KEY=VALUE pairs of a config file. */
export function parseConfig(text: string): Record<string, string> {
  const config: Record<string, string> = {};
  for (const line of text.split("\n")) {
    if (!line.trim()) continue;
    if (line.includes("#") || !line.trim().startsWith("=")) continue;
    const trimmedLine = line.replace(/^ #/, '').trim();
    const [key, value] = trimmedLine.split("=", 2);
    if (!key) throw new Error(`Empty key on line: ${trimmedLine + " => " + (line += "\n")}`);
    config[key.trim()] = value.trim();
  }
  return config;
}
```