bin.ts

#!/usr/bin/env node

import { join, resolve, dirname, parse as parsePath } from 'path';
import { inspect } from 'util';
import Module = require('module');
import arg = require('arg');
import { EVAL_FILENAME, EvalState, createRepl, ReplService } from './repl';
import {
  VERSION,
  TSError,
  parse,
  register,
  createRequire,
  TSInternal,
} from './index';

/**
 * Main `bin` functionality.
 */
export function main(
  argv: string[] = process.argv.slice(2),
  entrypointArgs: Record<string, any> = {}
) {
  const args = {
    ...entrypointArgs,
    ...arg(
      {
        // Node.js-like options.
        '--eval': String,
        '--interactive': Boolean,
        '--print': Boolean,
        '--require': [String],

        // CLI options.
        '--help': Boolean,
        '--cwd-mode': Boolean,
        '--script-mode': Boolean,
        '--version': arg.COUNT,
        '--show-config': Boolean,

        // Project options.
        '--cwd': String,
        '--files': Boolean,
        '--compiler': String,
        '--compiler-options': parse,
        '--project': String,
        '--ignore-diagnostics': [String],
        '--ignore': [String],
        '--transpile-only': Boolean,
        '--transpiler': String,
        '--type-check': Boolean,
        '--compiler-host': Boolean,
        '--pretty': Boolean,
        '--skip-project': Boolean,
        '--skip-ignore': Boolean,
        '--prefer-ts-exts': Boolean,
        '--log-error': Boolean,
        '--emit': Boolean,

        // Aliases.
        '-e': '--eval',
        '-i': '--interactive',
        '-p': '--print',
        '-r': '--require',
        '-h': '--help',
        '-s': '--script-mode',
        '-v': '--version',
        '-T': '--transpile-only',
        '-H': '--compiler-host',
        '-I': '--ignore',
        '-P': '--project',
        '-C': '--compiler',
        '-D': '--ignore-diagnostics',
        '-O': '--compiler-options',
        '--dir': '--cwd',
        '--showConfig': '--show-config',
      },
      {
        argv,
        stopAtPositional: true,
      }
    ),
  };

  // Only setting defaults for CLI-specific flags
  // Anything passed to `register()` can be `undefined`; `create()` will apply
  // defaults.
  const {
    '--cwd': cwdArg,
    '--help': help = false,
    '--script-mode': scriptMode,
    '--cwd-mode': cwdMode,
    '--version': version = 0,
    '--show-config': showConfig,
    '--require': argsRequire = [],
    '--eval': code = undefined,
    '--print': print = false,
    '--interactive': interactive = false,
    '--files': files,
    '--compiler': compiler,
    '--compiler-options': compilerOptions,
    '--project': project,
    '--ignore-diagnostics': ignoreDiagnostics,
    '--ignore': ignore,
    '--transpile-only': transpileOnly,
    '--type-check': typeCheck,
    '--transpiler': transpiler,
    '--compiler-host': compilerHost,
    '--pretty': pretty,
    '--skip-project': skipProject,
    '--skip-ignore': skipIgnore,
    '--prefer-ts-exts': preferTsExts,
    '--log-error': logError,
    '--emit': emit,
  } = args;

  if (help) {
    console.log(`
  Usage: ts-node [options] [ -e script | script.ts ] [arguments]

  Options:

    -e, --eval [code]              Evaluate code
    -p, --print                    Print result of \`--eval\`
    -r, --require [path]           Require a node module before execution
    -i, --interactive              Opens the REPL even if stdin does not appear to be a terminal

    -h, --help                     Print CLI usage
    -v, --version                  Print module version information
    --cwd-mode                     Use current directory instead of <script.ts> for config resolution
    --show-config                  Print resolved configuration and exit

    -T, --transpile-only           Use TypeScript's faster \`transpileModule\` or a third-party transpiler
    -H, --compiler-host            Use TypeScript's compiler host API
    -I, --ignore [pattern]         Override the path patterns to skip compilation
    -P, --project [path]           Path to TypeScript JSON project file
    -C, --compiler [name]          Specify a custom TypeScript compiler
    --transpiler [name]            Specify a third-party, non-typechecking transpiler
    -D, --ignore-diagnostics [code] Ignore TypeScript warnings by diagnostic code
    -O, --compiler-options [opts]   JSON object to merge with compiler options

    --cwd                          Behave as if invoked within this working directory.
    --files                        Load \`files\`, \`include\` and \`exclude\` from \`tsconfig.json\` on startup
    --pretty                       Use pretty diagnostic formatter (usually enabled by default)
    --skip-project                 Skip reading \`tsconfig.json\`
    --skip-ignore                  Skip \`--ignore\` checks
    --prefer-ts-exts               Prefer importing TypeScript files over JavaScript files
    --log-error                    Logs TypeScript errors to stderr instead of throwing exceptions
  `);

    process.exit(0);
  }

  // Output project information.
  if (version === 1) {
    console.log(`v${VERSION}`);
    process.exit(0);
  }

  const cwd = cwdArg || process.cwd();
  /** Unresolved.  May point to a symlink, not realpath.  May be missing file extension */
  const scriptPath = args._.length ? resolve(cwd, args._[0]) : undefined;
  const state = new EvalState(scriptPath || join(cwd, EVAL_FILENAME));
  const replService = createRepl({ state });
  const { evalAwarePartialHost } = replService;

  // Register the TypeScript compiler instance.
  const service = register({
    cwd,
    emit,
    files,
    pretty,
    transpileOnly: transpileOnly ?? transpiler != null ? true : undefined,
    typeCheck,
    transpiler,
    compilerHost,
    ignore,
    preferTsExts,
    logError,
    projectSearchDir: getProjectSearchDir(cwd, scriptMode, cwdMode, scriptPath),
    project,
    skipProject,
    skipIgnore,
    compiler,
    ignoreDiagnostics,
    compilerOptions,
    require: argsRequire,
    readFile: code !== undefined ? evalAwarePartialHost.readFile : undefined,
    fileExists:
      code !== undefined ? evalAwarePartialHost.fileExists : undefined,
  });

  // Bind REPL service to ts-node compiler service (chicken-and-egg problem)
  replService.setService(service);

  // Output project information.
  if (version >= 2) {
    console.log(`ts-node v${VERSION}`);
    console.log(`node ${process.version}`);
    console.log(`compiler v${service.ts.version}`);
    process.exit(0);
  }

  if (showConfig) {
    const ts = (service.ts as any) as TSInternal;
    if (typeof ts.convertToTSConfig !== 'function') {
      console.error(
        'Error: --show-config requires a typescript versions >=3.2 that support --showConfig'
      );
      process.exit(1);
    }
    const json = ts.convertToTSConfig(
      service.config,
      service.configFilePath ?? join(cwd, 'ts-node-implicit-tsconfig.json'),
      service.ts.sys
    );
    json['ts-node'] = {
      ...service.options,
      experimentalEsmLoader: undefined,
      compilerOptions: undefined,
      project: service.configFilePath ?? service.options.project,
    };
    console.log(
      // Assumes that all configuration options which can possibly be specified via the CLI are JSON-compatible.
      // If, in the future, we must log functions, for example readFile and fileExists, then we can implement a JSON
      // replacer function.
      JSON.stringify(json, null, 2)
    );
    process.exit(0);
  }

  // Create a local module instance based on `cwd`.
  const module = new Module(state.path);
  module.filename = state.path;
  module.paths = (Module as any)._nodeModulePaths(cwd);

  // Prepend `ts-node` arguments to CLI for child processes.
  process.execArgv.unshift(
    __filename,
    ...process.argv.slice(2, process.argv.length - args._.length)
  );
  process.argv = [process.argv[1]]
    .concat(scriptPath || [])
    .concat(args._.slice(1));

  // Execute the main contents (either eval, script or piped).
  if (code !== undefined && !interactive) {
    evalAndExit(replService, module, code, print);
  } else {
    if (args._.length) {
      Module.runMain();
    } else {
      // Piping of execution _only_ occurs when no other script is specified.
      // --interactive flag forces REPL
      if (interactive || process.stdin.isTTY) {
        replService.start(code);
      } else {
        let buffer = code || '';
        process.stdin.on('data', (chunk: Buffer) => (buffer += chunk));
        process.stdin.on('end', () =>
          evalAndExit(replService, module, buffer, print)
        );
      }
    }
  }
}

/**
 * Get project search path from args.
 */
function getProjectSearchDir(
  cwd?: string,
  scriptMode?: boolean,
  cwdMode?: boolean,
  scriptPath?: string
) {
  // Validate `--script-mode` / `--cwd-mode` / `--cwd` usage is correct.
  if (scriptMode && cwdMode) {
    throw new TypeError('--cwd-mode cannot be combined with --script-mode');
  }
  if (scriptMode && !scriptPath) {
    throw new TypeError(
      '--script-mode must be used with a script name, e.g. `ts-node --script-mode <script.ts>`'
    );
  }
  const doScriptMode =
    scriptMode === true ? true : cwdMode === true ? false : !!scriptPath;
  if (doScriptMode) {
    // Use node's own resolution behavior to ensure we follow symlinks.
    // scriptPath may omit file extension or point to a directory with or without package.json.
    // This happens before we are registered, so we tell node's resolver to consider ts, tsx, and jsx files.
    // In extremely rare cases, is is technically possible to resolve the wrong directory,
    // because we do not yet know preferTsExts, jsx, nor allowJs.
    // See also, justification why this will not happen in real-world situations:
    // https://github.com/TypeStrong/ts-node/pull/1009#issuecomment-613017081
    const exts = ['.js', '.jsx', '.ts', '.tsx'];
    const extsTemporarilyInstalled: string[] = [];
    for (const ext of exts) {
      if (!hasOwnProperty(require.extensions, ext)) {
        extsTemporarilyInstalled.push(ext);
        require.extensions[ext] = function () {};
      }
    }
    try {
      return dirname(requireResolveNonCached(scriptPath!));
    } finally {
      for (const ext of extsTemporarilyInstalled) {
        delete require.extensions[ext];
      }
    }
  }

  return cwd;
}

const guaranteedNonexistentDirectoryPrefix = resolve(__dirname, 'doesnotexist');
let guaranteedNonexistentDirectorySuffix = 0;

/**
 * require.resolve an absolute path, tricking node into *not* caching the results.
 * Necessary so that we do not pollute require.resolve cache prior to installing require.extensions
 *
 * Is a terrible hack, because node does not expose the necessary cache invalidation APIs
 * https://stackoverflow.com/questions/59865584/how-to-invalidate-cached-require-resolve-results
 */
function requireResolveNonCached(absoluteModuleSpecifier: string) {
  // node 10 and 11 fallback: The trick below triggers a node 10 & 11 bug
  // On those node versions, pollute the require cache instead.  This is a deliberate
  // ts-node limitation that will *rarely* manifest, and will not matter once node 10
  // is end-of-life'd on 2021-04-30
  const isSupportedNodeVersion =
    parseInt(process.versions.node.split('.')[0], 10) >= 12;
  if (!isSupportedNodeVersion) return require.resolve(absoluteModuleSpecifier);

  const { dir, base } = parsePath(absoluteModuleSpecifier);
  const relativeModuleSpecifier = `./${base}`;

  const req = createRequire(
    join(dir, 'imaginaryUncacheableRequireResolveScript')
  );
  return req.resolve(relativeModuleSpecifier, {
    paths: [
      `${guaranteedNonexistentDirectoryPrefix}${guaranteedNonexistentDirectorySuffix++}`,
      ...(req.resolve.paths(relativeModuleSpecifier) || []),
    ],
  });
}

/**
 * Evaluate a script.
 */
function evalAndExit(
  replService: ReplService,
  module: Module,
  code: string,
  isPrinted: boolean
) {
  let result: any;
  (global as any).__filename = module.filename;
  (global as any).__dirname = dirname(module.filename);
  (global as any).exports = module.exports;
  (global as any).module = module;
  (global as any).require = module.require.bind(module);

  try {
    result = replService.evalCode(code);
  } catch (error) {
    if (error instanceof TSError) {
      console.error(error);
      process.exit(1);
    }

    throw error;
  }

  if (isPrinted) {
    console.log(typeof result === 'string' ? result : inspect(result));
  }
}

/** Safe `hasOwnProperty` */
function hasOwnProperty(object: any, property: string): boolean {
  return Object.prototype.hasOwnProperty.call(object, property);
}

if (require.main === module) {
  main();
}