make-ts-from-graphql

make-ts-from-graphql.ts

#!/usr/bin/env ts-node

/// <reference types="node" />

import glob from 'fast-glob'
import fs from 'fs'
import path from 'path'
import yargs from 'yargs'

const defaultPatterns = ['**/*.graphql', '**/*.gql', '!node_modules']

const argv = yargs
  .usage('$0 [options] [patterns]\n\n  patterns    default: ' + defaultPatterns.join(' '))
  .option('target', {
    alias: 't',
    describe: 'Generate code for language (ts or js)',
    string: true,
    default: fs.existsSync('tsconfig.json') ? 'ts' : 'js',
  })
  .option('quiet', {
    alias: 'q',
    describe: 'Do not log currently processed files',
    boolean: true,
    default: false,
  })
  .help('help')
  .alias('help', 'h')
  .alias('version', 'V')
  .strict().argv

const patterns = argv._.length ? argv._ : defaultPatterns

function upperFirst(str: string): string {
  return str[0].toUpperCase() + str.slice(1)
}

function camelize(str: string): string {
  return str.split(/[\x00-\x2f\x3a-\x40\x5b-\x60\x7b-\x7f]+/).reduce((result, word, index) => {
    word = word.toLowerCase()
    return result + (index ? upperFirst(word) : word)
  }, '')
}

const BACKTICK = '`'
const LF = '\n'

function jsTemplate(variable: string, graphqlContent: string): string {
  const content = graphqlContent
    .replace(/\s*$/, '')
    .replace(/'/g, "\\'")
    .replace(/\n/g, '\\n')
  return [
    '// eslint:disable',
    '"use strict"',
    'var gql = require("graphql-tag")',
    `module.exports = gql(['${content}'])`,
    `module.exports.default = module.exports`,
    `module.exports.${variable} = module.exports`,
    '',
  ].join('\n')
}

function tsTemplate(variable: string, graphqlContent: string): string {
  const content = graphqlContent.replace(/^/gm, '  ').replace(/\s*$/, '')
  return [
    '// tslint:disable',
    'import {DocumentNode} from "graphql"',
    'import gql from "graphql-tag"',
    '// prettier-ignore',
    `export const ${variable}: DocumentNode = gql${BACKTICK}${LF}${content}${LF}${BACKTICK}`,
    `export default ${variable}`,
    '',
  ].join('\n')
}

function targetTemplate(variable: string, graphqlContent: string): string {
  if (argv.target === 'ts') {
    return tsTemplate(variable, graphqlContent)
  } else {
    return jsTemplate(variable, graphqlContent)
  }
}

glob<string>(patterns, {stats: false}).then(files => {
  for (const graphqlFile of files) {
    const graphqlExt = path.extname(graphqlFile)
    if (graphqlExt !== '.graphql' && graphqlExt !== '.gql') {
      console.info(`Skipping file ${graphqlFile}`)
      continue
    }
    const graphqlBasename = path.basename(graphqlFile, graphqlExt)
    const targetExt = argv.target === 'ts' ? '.ts' : '.js'
    const targetFile = path.join(path.dirname(graphqlFile), graphqlBasename) + targetExt
    if (!argv.quiet) {
      console.info(`Creating ${targetFile} from ${graphqlFile}`)
    }
    const graphqlContent = fs.readFileSync(graphqlFile).toString()
    const targetVariable = camelize(`${graphqlBasename} Query`)
    const targetContent = targetTemplate(targetVariable, graphqlContent)
    fs.writeFileSync(targetFile, targetContent)
  }
})