function-type-expressions

When using function expressions (not statements), you can apply a type to the entire function. This reduces repetition, improves type safety, and makes code more readable.

Without the function type, this would only error at call sites.

Response: With shared signatures, centralizing the type removes noise.

在编写具有相同签名的多个函数时使用。在实现回调时使用。在匹配现有函数类型时使用。 来源：marius-townhouse/effective-typescript-skills。