graphql-typed-client/src/cliHelpers/validateConfigs.ts

A tool that generates a strongly typed client library for any GraphQL endpoint. The client allows writing GraphQL queries as plain JS objects (with type safety, awesome code completion experience, custom scalar type mapping, type guards and more)

import chalk from 'chalk'
import { Config } from '../config'

export const validateConfigs = (configs: Config[]) => {
  const errors = []

  if (configs.length === 0) errors.push('config array is empty')

  configs.forEach((config, i) => {
    const whichConfig = configs.length === 1 ? 'the config' : `config #${i + 1}`

    if (!config.endpoint && !config.schema && !config.fetcher)
      errors.push(`you didn't provide either \`endpoint\`, \`schema\` or \`fetcher\` option in ${whichConfig}`)

    if ([config.endpoint, config.schema, config.fetcher].filter(i => i).length > 1)
      errors.push(
        `you provided two or more conflicting options in ${whichConfig}, only one of either \`endpoint\`, \`schema\` or \`fetcher\` is allowed`,
      )

    if (!config.output) errors.push(`you didn't provide an \`output\` option in ${whichConfig}`)
  })

  errors.forEach(error => console.log(chalk.red(`Error: ${error}`)))

  return errors.length === 0
}