ts-node.ts

import * as fs from 'fs'
import * as path from 'path'
import * as TSNode from 'ts-node'

import Debug from './debug'
// eslint-disable-next-line new-cap
const debug = Debug()

const tsconfigs: {[root: string]: TSConfig} = {}
const rootDirs: string[] = []
const typeRoots = [`${__dirname}/../node_modules/@types`]

export interface TSConfig {
  compilerOptions: {
    rootDir?: string;
    rootDirs?: string[];
    outDir?: string;
    target?: string;
    esModuleInterop?: boolean;
    experimentalDecorators?: boolean;
    emitDecoratorMetadata?: boolean;
  };
}

function loadTSConfig(root: string): TSConfig | undefined {
  const tsconfigPath = path.join(root, 'tsconfig.json')
  let typescript: typeof import('typescript') | undefined
  try {
    typescript = require('typescript')
  } catch {
    try {
      typescript = require(root + '/node_modules/typescript')
    } catch { }
  }

  if (fs.existsSync(tsconfigPath) && typescript) {
    const tsconfig = typescript.parseConfigFileTextToJson(
      tsconfigPath,
      fs.readFileSync(tsconfigPath, 'utf8'),
    ).config
    if (!tsconfig || !tsconfig.compilerOptions) {
      throw new Error(
        `Could not read and parse tsconfig.json at ${tsconfigPath}, or it ` +
        'did not contain a "compilerOptions" section.')
    }
    return tsconfig
  }
}

function registerTSNode(root: string) {
  if (process.env.OCLIF_TS_NODE === '0') return
  if (tsconfigs[root]) return
  const tsconfig = loadTSConfig(root)
  if (!tsconfig) return
  debug('registering ts-node at', root)
  const tsNodePath = require.resolve('ts-node', {paths: [root, __dirname]})
  const tsNode: typeof TSNode = require(tsNodePath)
  tsconfigs[root] = tsconfig
  typeRoots.push(`${root}/node_modules/@types`)
  if (tsconfig.compilerOptions.rootDirs) {
    rootDirs.push(...tsconfig.compilerOptions.rootDirs.map(r => path.join(root, r)))
  } else {
    rootDirs.push(`${root}/src`)
  }
  const cwd = process.cwd()
  try {
    process.chdir(root)
    tsNode.register({
      skipProject: true,
      transpileOnly: true,
      // cache: false,
      // typeCheck: true,
      compilerOptions: {
        esModuleInterop: tsconfig.compilerOptions.esModuleInterop,
        target: tsconfig.compilerOptions.target || 'es2017',
        experimentalDecorators: tsconfig.compilerOptions.experimentalDecorators || false,
        emitDecoratorMetadata: tsconfig.compilerOptions.emitDecoratorMetadata || false,
        module: 'commonjs',
        sourceMap: true,
        rootDirs,
        typeRoots,
        jsx: 'react',
      },
    })
  } finally {
    process.chdir(cwd)
  }
}

/**
 * convert a path from the compiled ./lib files to the ./src typescript source
 * this is for developing typescript plugins/CLIs
 * if there is a tsconfig and the original sources exist, it attempts to require ts-
 */
export function tsPath(root: string, orig: string): string
export function tsPath(root: string, orig: string | undefined): string | undefined
export function tsPath(root: string, orig: string | undefined): string | undefined {
  if (!orig) return orig
  orig = path.join(root, orig)
  try {
    registerTSNode(root)
    const tsconfig = tsconfigs[root]
    if (!tsconfig) return orig
    const {rootDir, rootDirs, outDir} = tsconfig.compilerOptions
    const rootDirPath = rootDir || (rootDirs || [])[0]
    if (!rootDirPath || !outDir) return orig
    // rewrite path from ./lib/foo to ./src/foo
    const lib = path.join(root, outDir) // ./lib
    const src = path.join(root, rootDirPath) // ./src
    const relative = path.relative(lib, orig) // ./commands
    const out = path.join(src, relative) // ./src/commands
    // this can be a directory of commands or point to a hook file
    // if it's a directory, we check if the path exists. If so, return the path to the directory.
    // For hooks, it might point to a module, not a file. Something like "./hooks/myhook"
    // That file doesn't exist, and the real file is "./hooks/myhook.ts"
    // In that case we attempt to resolve to the filename. If it fails it will revert back to the lib path
    if (fs.existsSync(out) || fs.existsSync(out + '.ts')) return out
    return orig
  } catch (error) {
    debug(error)
    return orig
  }
}