Check existance of flow header comment.
NOTE: This package is deprecated in favor of the require-valid-file-annotation rule in eslint-plugin-flowtype.
You'll first need to install ESLint:
$ npm i eslint --save-dev
Next, install eslint-plugin-flow-header:
$ npm install eslint-plugin-flow-header --save-dev
Note: If you installed ESLint globally (using the -g flag) then you must also install eslint-plugin-flow-header globally.
Add flow-header to the plugins section of your .eslintrc configuration file. You can omit the eslint-plugin- prefix:
{
"plugins": [
"flow-header"
]
}Then configure the rules you want to use under the rules section.
{
"rules": {
"flow-header/flow-header": 2
}
}