```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")) {
    // Skip blank lines and those starting with #
    if (/^\s*#|^$/g.test(line)) continue;

    const [key, value] = line.trim().split("=", 2);
    if (!key) throw new Error(`Empty key at line: ${line}`);
    config[key.trim()] = value || "";
  }
  return config;
}
```