Sets react-intl defaultMessage based on existing translation file

react-intl-default-message.ts

// Requires `npm i jscodeshift @types/jscodeshift`
// Run: `npx jscodeshift -t react-intl-default-message.ts src/**/*.ts`

import en from './src/i18n/locales/en.json'

export const parser = 'tsx'

export default function transformer(file, api) {
    const j = api.jscodeshift

    const messageDesc = (nodePath) => {
        const { node } = nodePath
        const [messageDescriptor, ...otherArguments] = node.arguments
        const { properties } = messageDescriptor

        if (!properties) {
            return node
        }

        const id = properties.find(p => p.key.name === 'id')
        const description = properties.find(p => p.key.name === 'description')
        const defaultMessage = en[id.value.value]

        const object = j.objectExpression([
            j.property(
                'init',
                j.identifier('id'),
                j.literal(id.value.value)
            ),
            j.property(
                'init',
                j.identifier('defaultMessage'),
                j.literal(defaultMessage)
            ),
            description && j.property(
                'init',
                j.identifier('description'),
                j.literal(description.value.value)
            )
        ].filter(Boolean))

        node.arguments = [object, ...otherArguments]

        return node
    }

    const jsxMessageDesc = (nodePath) => {
        const { node } = nodePath
        const { attributes } = node.openingElement

        const id = attributes.find(p => p.name.name === 'id')
        // const description = properties.find(p => p.name === 'description')
        // const values = properties.find(p => p.name === 'values')
        const defaultMessage = attributes.find(p => p.name.name === 'defaultMessage')

        if (defaultMessage) {
            defaultMessage.value.value = en[id.value.value]
        }
        else {
            attributes.push(j.jsxAttribute(
                j.jsxIdentifier('defaultMessage'),
                j.literal(en[id.value.value])
            ))
        }

        return node
    }

    const root = j(file.source)
    const intlFormatMessage = root
        .find(j.CallExpression, {
            callee: {
                type: 'MemberExpression',
                property: {
                    name: 'formatMessage'
                }
            }
        })

    const formatMessage = root
        .find(j.CallExpression, { callee: { name: 'formatMessage' } })

    const defineMessage = root
        .find(j.CallExpression, { callee: { name: 'defineMessage' } })

    const jsxFormattedMessage = root.findJSXElements('FormattedMessage')
    const jsxFormattedHtmlMessage = root.findJSXElements('FormattedHtmlMessage')
    const found = intlFormatMessage.length +
        formatMessage.length +
        defineMessage.length +
        jsxFormattedMessage.length +
        jsxFormattedHtmlMessage.length

    if (found === 0) {
        return file.source
    }

    if (intlFormatMessage.length > 0) {
        intlFormatMessage.replaceWith(messageDesc)
    }

    if (formatMessage.length > 0) {
        formatMessage.replaceWith(messageDesc)
    }

    if (defineMessage.length > 0) {
        defineMessage.replaceWith(messageDesc)
    }

    if (jsxFormattedMessage.length > 0) {
        jsxFormattedMessage.replaceWith(jsxMessageDesc)
    }

    if (jsxFormattedHtmlMessage.length > 0) {
        jsxFormattedHtmlMessage.replaceWith(jsxMessageDesc)
    }

    return root.toSource({ quote: 'single' })
}