```typescript
export function matchSetting(rules: Record<string, string>, name: string): string | null {
  if (typeof name !== "string" || name === "" || /\*/.test(name)) {
    throw new Error("name must be a star-free non-empty string");
  }

  for (const [selector, value] of Object.entries(rules)) {
    if (typeof value !== "string") {
      throw new Error("rule values must be strings");
    }

    if (selector === "*") {
      continue;
    } else if (name.startsWith(selector + ".*")) {
      return rules[selector];
    }
  }

  return null;
}
```