codemod - rewrite class methods as arrow function properties

class-methods-to-arrow-function-props.js

const IGNORE = [
  'constructor',
  'componentDidMount',
  'componentDidUpdate',
  'componentWillReceiveProps',
  'componentWillMount',
  'componentWillUpdate',
  'componentWillUnmount',
  'getChildContext',
  'getDefaultProps',
  'getInitialState',
  'render',
  'shouldComponentUpdate',
]

module.exports = function (file, api) {
  const j = api.jscodeshift

  const withComments = (to, from) => {
    to.comments = from.comments
    return to
  }

  const createArrowFunctionExpression = (fn) => {
    const arrowFunc = j.arrowFunctionExpression(fn.params, fn.body, false)

    arrowFunc.returnType = fn.returnType
    arrowFunc.defaults = fn.defaults
    arrowFunc.rest = fn.rest
    arrowFunc.async = fn.async

    return arrowFunc
  }

  const createArrowProperty = prop => withComments(
    j.classProperty(
      j.identifier(prop.key.name),
      createArrowFunctionExpression(prop),
      null,
      false,
    ),
    prop,
  )

  const root = j(file.source)

  const methods = root
    .find(j.ClassMethod)
    .filter(path => path.value.kind === 'method')
    .filter(path => !IGNORE.includes(path.value.key.name))

  methods.replaceWith(m => createArrowProperty(m.node))

  return root.toSource()
}

example.sh

jscodeshift -t class-methods-to-arrow-function-props.js.js --extensions js,jsx --parser babylon --parser-config ./parser-config.json src/

parser-config.json

{
  "sourceType": "module",
  "allowImportExportEverywhere": true,
  "allowReturnOutsideFunction": true,
  "startLine": 1,
  "tokens": true,
  "plugins": [
    ["flow", { "all": true }],
    "flowComments",
    "jsx",

    "asyncGenerators",
    "bigInt",
    "classProperties",
    "classPrivateProperties",
    "classPrivateMethods",
    ["decorators", { "decoratorsBeforeExport": true }],
    "doExpressions",
    "dynamicImport",
    "exportDefaultFrom",
    "exportNamespaceFrom",
    "functionBind",
    "functionSent",
    "importMeta",
    "logicalAssignment",
    "nullishCoalescingOperator",
    "numericSeparator",
    "objectRestSpread",
    "optionalCatchBinding",
    "optionalChaining",
    ["pipelineOperator", { "proposal": "minimal" }],
    "throwExpressions"
  ]
}

typo, it's jscodeshift -t class-methods-to-arrow-function-props.js