Flow报错[signature-verification-failure]：柯里化异步函数签名验证失败求助

错误信息 #

type Submit = {
  form: any,
  handleSubmit: FunctionType<any, any>,
  ...
}
Flow-IDE

Submit: type Submit = {
    form: any,
    handleSubmit: FunctionType < any,
    any > ,
    ...
}
Cannot build a typed interface for this module. You should annotate the exports of this module with types. Missing type annotation at function return:Flow(signature-verification-failure)
Cannot build a typed interface for this module. You should annotate the exports of this module with types. Missing type annotation at function return: [signature-verification-failure] (index.js:31:11)flow

问题代码 #

type Submit = {
  form: Object,
  handleSubmit: FunctionType<Object, any> // 自定义类型，可正常工作
};

export const onClickSubmit = ({
  form,
  handleSubmit
}: Submit) => async (input: Object): Promise<any> => {
  await handleSubmit(input);
  form.reset();
};

报错高亮在}: Submit)的右括号位置，尝试在):后添加类型定义无效。

解决方法 #

Flow需要明确标注导出函数的完整签名，包括外层函数的参数和返回的函数类型。可以通过以下两种方式修复：

方式一：定义类型别名后标注 #

type Submit = {
  form: Object,
  handleSubmit: FunctionType<Object, any>
};

// 定义外层函数的完整类型
type OnClickSubmitType = (props: Submit) => (input: Object) => Promise<any>;

export const onClickSubmit: OnClickSubmitType = ({
  form,
  handleSubmit
}) => async (input) => {
  await handleSubmit(input);
  form.reset();
};

方式二：直接标注完整类型 #

type Submit = {
  form: Object,
  handleSubmit: FunctionType<Object, any>
};

export const onClickSubmit: (props: Submit) => (input: Object) => Promise<any> = ({
  form,
  handleSubmit
}) => async (input) => {
  await handleSubmit(input);
  form.reset();
};

说明 #

原代码中仅标注了内部异步函数的类型，但外层函数的完整签名未显式声明，导致Flow无法生成模块的类型接口。通过显式指定导出函数的完整类型，即可解决该错误。

内容的提问来源于stack exchange，提问作者Brandon