npm run-script flow is not working

Question

I created a react native project, and I want to enable flow for my project.

I have flow-bin installed by

npm install --save flow-bin

However, it returns

missing script: flow 

when I run

npm run-script flow

Anyone got any idea? Thanks!

Answer 1

npm run-script flow will not execute the flow command, but will just look into the scripts entry in the package.json file and execute the command under the flow entry (see the documentation for more information). This has the advantage that it will include binaries located in your dependencies (a.k.a. binaries inside the node_modules folder), which is something you usually do not have in your $PATH, avoiding the need to configure that for every project. Make sure that your package.json looks something like this:

//...
"scripts":{
    //...
    "flow": "flow; test $? -eq 0 -o $? -eq 2"
}
//...

Source: docs

Answer 2

Add "flow": "flow" as a new entry under "scripts" in your package.json file:

  ...
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test --env=jsdom",
    "eject": "react-scripts eject",
    "flow": "flow"
  },
  ...

The tutorials I was following seem to skip this step but the Facebook github repo has it: https://facebook.github.io/create-react-app/docs/adding-flow