What does this Polymorphic Stream Type error mean instead of the intersection type?

Question

What does this Polymorphic Stream Type error mean instead of the intersection type?

What does this JS thread error mean?

Expected polymorphic type instead of any member of intersection type.

Details:

The error is displayed Documentin the export line below. I do not understand why this is happening or what I can do to fix it. (I tried to find this in the flow documentation, but still couldn't figure it out.)

// @flow
import Document, {Head, Main, NextScript} from 'next/document'

export default class IntlDocument extends Document {
  static async getInitialProps (context) {
    const props = await super.getInitialProps(context)
    const {req: {localeDataScript}} = context
    return {
      ...props,
      localeDataScript
    }
  }

  render () {
    return (
      <html>
        <Head />
        <body>
          <Main />
          <script
            dangerouslySetInnerHTML={{
              __html: this.props.localeDataScript
            }}
          />
          <NextScript />
        </body>
      </html>
    )
  }
}

And the type declaration next/documentis this:

declare module "next/document" {
  import type {Component} from 'react';

  declare type Context = {
    pathname: string,
    query: any,
    req?: any,
    res?: any,
    xhr?: any,
    err?: any,
  };
  declare export var Head: Class<Component<void, *, *>>;
  declare export var Main: Class<Component<void, *, *>>;
  declare export var NextScript: Class<Component<void, *, *>>;
  declare export default Class<Component<void, *, *>> & {
    getInitialProps: (ctx: Context) => Promise<*>;
    renderPage(cb: Function): void;
  };
}

+4

javascript flowtype next.js

django09 Jun 19 '17 at 4:39

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1 answer

Jesse Hallett · Answer 1 · 2017-11-15T21:18:33+0000

, Flow v0.53.0 . , React. , Component . .

(v0.59.0) :

Error: react.js:7
  7: export default class IntlDocument extends Document {
                                               ^^^^^^^^ identifier `Document`. Expected polymorphic type instead of any member of intersection type
  7: export default class IntlDocument extends Document {
                                               ^^^^^^^^ intersection
  Member 1:
   15:   declare export default Class<Component<*, *>> & {
                                ^^^^^^^^^^^^^^^^^^^^^^ class type: type application of Component. See lib: types/next-document.js:15
  Error:
    9:     const props = await super.getInitialProps(context)
                                     ^^^^^^^^^^^^^^^ property `getInitialProps`. Property not found in
    9:     const props = await super.getInitialProps(context)
                               ^^^^^ statics of React$Component
  Member 2:
                                                         v
   15:   declare export default Class<Component<*, *>> & {
   16:     getInitialProps: (ctx: Context) => Promise<*>;
   17:     renderPage(cb: Function): void;
   18:   };
         ^ object type. See lib: types/next-document.js:15
  Error:
    7: export default class IntlDocument extends Document {
                                                 ^^^^^^^^ identifier `Document`. Expected polymorphic type instead of
                                                         v
   15:   declare export default Class<Component<*, *>> & {
   16:     getInitialProps: (ctx: Context) => Promise<*>;
   17:     renderPage(cb: Function): void;
   18:   };
         ^ object type. See lib: types/next-document.js:15


Found 1 error

- Document ( "next/document"),

Class<Component<void, *, *>>

{
  getInitialProps: (ctx: Context) => Promise<*>;
  renderPage(cb: Function): void;
}

, , Document React Component getInitialProps renderPage. getInitialProps renderPage , Document. , Flow ; super.getInitialProps(context) .

super.getInitialProps(context) Document.getInitialProps(context).

- "next/document":

declare export default class Document<Props, State = void> extends React$Component<Props, State> {
  static getInitialProps(ctx: Context): Promise<Props>;
  static renderPage(cb: Function): void;
}

, . Component :

import type {Component} from 'react';

- . , - , , . Component, , Flow , . , :

types/next-document.js:26
 26:   declare export default class Document<Props, State = void> extends Component<Props, State> {
                                                                          ^^^^^^^^^ Component. type referenced from value position
  2:   import type {Component} from 'react';
                    ^^^^^^^^^ type Component

, - . , .

, React ( Flow, . react.js) , , - . . , React$Component ; .

What does this Polymorphic Stream Type error mean instead of the intersection type?

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