jsx2 wrapper for jsx3 bindings

jsx2-wrapper.js

// requires node 12.*
const fs = require('fs')
const path = require('path')
const refmt = require('reason');

const dir = path.resolve(process.argv[2])

if (!fs.existsSync(dir)) {
  console.error(`${dir} doesn't exist`);
  return
}

fs.readdirSync(dir)
  .filter(fileName => fileName.endsWith(".re"))
  .forEach(fileName => {
    console.log(`working on ${fileName}...`)
    const filePath = path.join(dir, fileName)
    const content = fs.readFileSync(filePath, 'utf-8')
    const lines = content.split(/[\n\r]/)

    const props = lines.flatMap(line => {
      const matches = line.match(/(~(.+?): (.+?),)/g)

      if (!matches) return []

      return matches.map(match => {
        const m = match.split(/[~:,]/)

        return {
          name: m[1].trim(),
          isOptional: m[2].trim().endsWith("?")
        }
      })
    })

    if (!props.length) return true

    const propsStr = props
      .map(prop => {
        const isChildren = prop.name == "children"
        return `${isChildren ? "" : "~"}${prop.name}${prop.isOptional && !isChildren ? "=?" : ""}`
      })
      .join(",");
    const makePropsStr = props
      .map(prop => `~${prop.name}${prop.isOptional && prop.name != "children" ? "?" : ""}`)
      .join(",");
    const hasChildren = props.some(prop => prop.name == "children")

    const jsx2 = `
      module Jsx2 = {
        let component = ReasonReact.statelessComponent(__MODULE__);

        let make = (${propsStr}) => {
          ${hasChildren ? "let children = React.array(children);" : ""}
          ReasonReactCompat.wrapReactForReasonReact(
            make,
            makeProps(${makePropsStr}, ()),
            children,
          );
        };
      };
    `

    const parsedJsx2 = refmt.parseRE(jsx2);
    const formattedJsx2 = refmt.printRE(parsedJsx2);

    fs.appendFileSync(filePath, '\n' + formattedJsx2);

    console.log(`${fileName} updated!`)
  })