cli.js

/**
 * @copyright Copyright 2017-2021 Kevin Locke <kevin@kevinlocke.name>
 * @license MIT
 * @module procore-docs-to-openapi/cli.js
 */

import { Command } from 'commander';
// TODO [engine:node@>=14]: import { readFile } from 'fs/promises'
import { promises as fsPromises } from 'fs';
import { format } from 'util';

import ProcoreFixupsTransformer from './fixups.js';
import ProcoreApiDocToOpenApiTransformer from './index.js';
import combineOpenapi from './combine.js';
import { procoreApiDocToOpenApiTransformerMockSymbol } from './lib/symbols.js';
import toJsonPointer from './lib/to-json-pointer.js';

const { readFile } = fsPromises;

/** Option parser to count the number of occurrences of the option.
 *
 * @private
 * @param {boolean|string} optarg Argument passed to option (ignored).
 * @param {number=} previous Previous value of option (counter).
 * @returns {number} previous + 1.
 */
function countOption(optarg, previous) {
  return (previous || 0) + 1;
}

async function readJson(pathOrUrl, options) {
  const content = await readFile(pathOrUrl, { encoding: 'utf8', ...options });
  return JSON.parse(content);
}

function streamToString(readable) {
  return new Promise((resolve, reject) => {
    let str = '';
    readable.on('data', (data) => {
      // Converting Buffer to string here could break multi-byte chars.
      // It's also inefficient.  Require callers to .setEncoding().
      if (typeof data !== 'string') {
        readable.destroy(new TypeError(
          `expected string, got ${typeof data} from stream`,
        ));
      }

      str += data;
    });
    readable.once('error', reject);
    readable.once('end', () => resolve(str));
  });
}

async function streamToJson(stream) {
  try {
    const json = await streamToString(stream);
    return JSON.parse(json);
  } catch (err) {
    const filename = stream.path || '-';
    err.message += ` in ${filename}`;
    throw err;
  }
}

/** Options for command entry points.
 *
 * @typedef {{
 *   env: !object<string,string>,
 *   stdin: !module:stream.Readable,
 *   stdout: !module:stream.Writable,
 *   stderr: !module:stream.Writable
 * }} CommandOptions
 * @property {!object<string,string>} env Environment variables.
 * @property {!module:stream.Readable} stdin Stream from which input is read.
 * @property {!module:stream.Writable} stdout Stream to which output is
 * written.
 * @property {!module:stream.Writable} stderr Stream to which errors and
 * non-output status messages are written.
 */
// const CommandOptions;

/** Entry point for this command.
 *
 * @param {!Array<string>} args Command-line arguments.
 * @param {!CommandOptions} options Options.
 * @returns {!Promise<number>} Promise for exit code.  Only rejected for
 * arguments with invalid type (or args.length < 2).
 */
export default async function procoreDocsToOpenapiMain(args, options) {
  if (!Array.isArray(args) || args.length < 2) {
    throw new TypeError('args must be an Array with at least 2 items');
  }

  if (!options || typeof options !== 'object') {
    throw new TypeError('options must be an object');
  }

  if (!options.stdin || typeof options.stdin.on !== 'function') {
    throw new TypeError('options.stdin must be a stream.Readable');
  }
  if (!options.stdout || typeof options.stdout.write !== 'function') {
    throw new TypeError('options.stdout must be a stream.Writable');
  }
  if (!options.stderr || typeof options.stderr.write !== 'function') {
    throw new TypeError('options.stderr must be a stream.Writable');
  }

  let errVersion;
  const command = new Command()
    .exitOverride()
    .configureOutput({
      writeOut: (str) => options.stdout.write(str),
      writeErr: (str) => options.stderr.write(str),
      getOutHelpWidth: () => options.stdout.columns,
      getErrHelpWidth: () => options.stderr.columns,
    })
    .arguments('[file...]')
    .allowExcessArguments(false)
    .description('Command description.')
    .option('-q, --quiet', 'print less output', countOption)
    .option('-v, --verbose', 'print more output', countOption)
    // TODO: Replace with .version(packageJson.version) loaded as JSON module
    // https://github.com/nodejs/node/issues/37141
    .option('-V, --version', 'output the version number')
    // throw exception to stop option parsing early, as commander does
    // (e.g. to avoid failing due to missing required arguments)
    .on('option:version', () => {
      errVersion = new Error('version');
      throw errVersion;
    });

  try {
    command.parse(args);
  } catch (errParse) {
    if (errVersion) {
      const packageJson =
        await readJson(new URL('package.json', import.meta.url));
      options.stdout.write(`${packageJson.version}\n`);
      return 0;
    }

    // If a non-Commander error was thrown, treat it as unhandled.
    // It probably represents a bug and has not been written to stdout/stderr.
    // throw commander.{CommanderError,InvalidArgumentError} to avoid.
    if (typeof errParse.code !== 'string'
      || !errParse.code.startsWith('commander.')) {
      throw errParse;
    }

    return errParse.exitCode !== undefined ? errParse.exitCode : 1;
  }

  const argOpts = command.opts();

  const filenames = command.args;
  if (filenames.length === 0) {
    if (options.stdin.isTTY) {
      options.stderr.write(
        'Warning: No filename given.  Reading Procore API JSON from stdin.\n',
      );
    }

    filenames.push('-');
  }

  const verbosity = (argOpts.verbose || 0) - (argOpts.quiet || 0);
  try {
    const docs = await Promise.all(filenames.map((filename) => {
      if (filename === '-') {
        options.stdin.setEncoding('utf8');
        return streamToJson(options.stdin);
      }

      return readJson(filename);
    }));
    const ProcoreApiDocToOpenApiTransformerOrMock =
      options[procoreApiDocToOpenApiTransformerMockSymbol]
      || ProcoreApiDocToOpenApiTransformer;
    const transformer = new ProcoreApiDocToOpenApiTransformerOrMock();
    const openapiDocs = docs.map((doc, i) => {
      if (verbosity >= 0) {
        transformer.warn = function(...values) {
          options.stderr.write(
            `${filenames[i]}:${toJsonPointer(this.transformPath)}: ${
              format(...values)}\n`,
          );
        };
      }

      return transformer.transformApiDoc(doc);
    });

    const combined = openapiDocs.length < 2 ? openapiDocs[0]
      : combineOpenapi(openapiDocs);

    const fixed = new ProcoreFixupsTransformer().transformOpenApi(combined);

    options.stdout.write(JSON.stringify(fixed, undefined, 2));
    return 0;
  } catch (err) {
    options.stderr.write(`${err}\n`);
    return 1;
  }
}