graphql-generate-flow-schema-assets/src/index.js

Generate Flow assets from GraphQL schema.

#!/usr/bin/env node
const fs = require('fs');
const path = require('path');
const program = require('commander');
const chalk = require('chalk');
const packageJson = require('../package');
const generateObjectTypes = require('./generateObjectTypes');
const generateEnums = require('./generateEnums');
const parseSchema = require('./parseSchema');

program
  .version(packageJson.version)
  .option('-s, --schema <path>', 'Path to schema.json or schema.graphql.')
  .option('-e, --enums', 'Generate enums.')
  .option(
    '--enums-file-path <path>',
    'File path to generate enums to. Defaults to current folder and enums.js.flow.'
  )
  .option('-o, --object-types', 'Generate object types.')
  .option(
    '--object-types-file-path <path>',
    'File path to generate object types to. Defaults to current folder and object-types.js.flow.'
  )
  .parse(process.argv);

(async function() {
  let schema;

  try {
    const rawSchema = fs.readFileSync(path.resolve(program.schema), 'utf8');
    schema = await parseSchema(rawSchema, program.schema);
  } catch (e) {
    console.error('Could not load schema.');
    process.exit(0);
  }

  let types;

  if (schema.__schema) {
    types = schema.__schema.types;
  } else if (schema.data && schema.data.__schema) {
    types = schema.data.__schema.types;
  } else {
    throw new Error(`Could not find types in schema. 
  Please make sure the schema is available on the prop '__schema' on the first level of the schema.json, 
  or nested under a prop called 'data' on the first level of the schema.json.`);
  }

  /**
   * ENUMS
   */

  if (!!program.enums) {
    console.log(chalk.yellow('Generating enums...'));
    const enumOutput = generateEnums(types);
    const enumsFilePath = path.resolve(
      typeof program.enumsFilePath === 'string'
        ? program.enumsFilePath
        : './enums.js'
    );

    console.log(chalk.green(`Enums generated to file ${enumsFilePath}`));
    fs.writeFileSync(enumsFilePath, enumOutput);
  }

  /**
   * OBJECT TYPES
   */

  if (!!program.objectTypes) {
    console.log(chalk.yellow('Generating object types...'));
    const objectTypesOutput = generateObjectTypes(types);
    const objectTypesFilePath = path.resolve(
      typeof program.objectTypesFilePath === 'string'
        ? program.objectTypesFilePath
        : './object-types.js'
    );
    console.log(
      chalk.green(`Object types generated to file ${objectTypesFilePath}`)
    );
    fs.writeFileSync(objectTypesFilePath, objectTypesOutput);
  }
})();