create-react-app-with-flow example doesn't pass flow

• I have searched the issues of this repository and believe that this is not a duplicate.

Expected Behavior

Following the example instructions for example should result in a project that passes Flow.

Current Behavior

• Following directions results in many errors from “yarn flow”, the first of which is a reference to chai. Most of these errors are coming from code in node_modules.

After modifying .flowconfig to exclude all node_modules files, project still gets many errors. Here are the first few.

yarn run v1.6.0
$ flow
Error: src/pages/index.js:53
     v
 53:       <div className={this.props.classes.root}>
 54:         <Dialog open={this.state.open} onClose={this.handleClose}>
 55:           <DialogTitle>Super Secret Password</DialogTitle>
...:
 74:       </div>
           ^ children array. This type is incompatible with
 20:   | Iterable<React$Node>;
         ^^^^^^^^^^^^^^^^^^^^ $Iterable. See lib: /private/tmp/flow/flowlib_173ced39/react.js:20
  Property `@@iterator` is incompatible:
    197:     @@iterator(): Iterator<T>;
             ^^^^^^^^^^^^^^^^^^^^^^^^^ function type. This type is incompatible with. See lib: /private/tmp/flow/flowlib_173ced39/core.js:197
    503:     @@iterator(): $Iterator<Yield,Return,Next>;
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ function type. See lib: /private/tmp/flow/flowlib_173ced39/core.js:503
      The return is incompatible:
        197:     @@iterator(): Iterator<T>;
                               ^^^^^^^^^^^ $Iterator. Has some incompatible type argument with. See lib: /private/tmp/flow/flowlib_173ced39/core.js:197
        503:     @@iterator(): $Iterator<Yield,Return,Next>;
                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ $Iterator. See lib: /private/tmp/flow/flowlib_173ced39/core.js:503
          Type argument `Yield` is incompatible:
             54:         <Dialog open={this.state.open} onClose={this.handleClose}>
                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ React.Element. This type is incompatible with

Steps to Reproduce (for bugs)

git clone https://github.com/mui-org/material-ui.git mui
cd mui/examples/create-react-app-with-flow
yarn install
yarn global add flow-typed
flow-typed install
yarn flow

• this is where you see the chai errors and many more from node_modules tree

Try modifying .flowconfig to exclude entire node_modules/ tree.

• this is where you see the other errors

Context

It’s hard to use this as an example of using Flow with Material UI when it doesn’t pass Flow.

Your Environment

  "name": "create-react-app-with-flow",
  "version": "1.0.0",
  "private": true,
  "dependencies": {
    "material-ui": "^1.0.0-beta.26",
    "prop-types": "^15.6.0",
    "react": "^16.0.0",
    "react-dom": "^16.0.0",
    "react-scripts": "^1.0.16"
  },
  "devDependencies": {
    "flow-bin": "^0.62.0"
  },

[prastut]

@oliviertassinari updating flow type fixed the errors for me. Few ♥️ members of the community + me are contributing to the type defs as an when we fix them inside our codebase.

[rosskevin]

My preference is to remove the flow example - the documentation already points to flow-typed, but if @prastut wants to PR the update that’s fine too.