```ts
/** 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() === "" || line.startsWith("#")) continue;
    const [key, value] = line.trim().split(/=(.+)/, 2);
    if (!key) throw new Error(`Invalid config line: ${JSON.stringify(line)}`);
    config[key.trim()] = value?.trim() ?? "";
  }
  return config;
}
```