精緻檢查器

Refine 的核心是 Checker<T> 類型。檢查器基本上就是函式，可接收一個 混合 (對於 Flow) 或 未知 (對於 TypeScript) 值，並傳回一個 CheckResult<T>...

/**
 * a function which checks if a given mixed value matches a type V,
 * returning the value if it does, otherwise a failure message.
 */
type Checker<+V> = (
  value: mixed,
  // optional path within a parent object tree to the current value
  path?: $ReadOnlyArray<string>,
) => CheckResult<V>;

/**
 * the result of checking whether a type matches an expected value
 */
type CheckResult<+V> = CheckSuccess<V> | CheckFailure;

/**
 * the result of failing to match a value to its expected type
 */
type CheckFailure = $ReadOnly<{
  type: 'failure',
  message: string,
  path: $ReadOnlyArray<string>,
}>;

/**
 * the result of successfully matching a value to its expected type
 */
type CheckSuccess<+V> = $ReadOnly<{
  type: 'success',
  value: V,
  // if using `nullable()` with the `nullWithWarningWhenInvalid` option,
  // failures that would have failed the check are appended as warnings
  // here on the success result.
  warnings: $ReadOnlyArray<CheckFailure>
}>;

下列詳細說明的內建檢查器允許輕鬆建構。這能夠使用基本原語建立更複雜的檢查器

// type PersonType = $ReadOnly<{name: string, friends: ?Array<PersonType>}>
// const Person: Checker<PersonType>
const Person = object({
  name: string(),
  friends: nullable(array(lazy(() => Person)))
});

Refine 提供許多內建檢查器，請參閱各個文件頁面以取得更多資訊

• 原始檢查器
• 集合檢查器
• 進階檢查器

此外，Refine 提供一些 實用程式函式，用於常見的使用案例，例如 JSON 解析和驗證函式。