feat(cli): adds a cli tool to migrate old config

TSJest migrates the config on the fly to stay compatible with older
versions, but it generates warning. This adds a cli tool which users can
call to migrate their configuraton easily without opening an issue :D

cli.js

@@ -0,0 +1,3 @@
+#!/usr/bin/env node
+
+require('./dist/cli')

package.json

@@ -3,6 +3,7 @@
   "version": "23.10.0-beta.2",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
+  "bin": "cli.js",
   "description": "A preprocessor with sourcemap support to help use Typescript with Jest",
   "scripts": {
     "prebuild": "node scripts/clean-dist.js",
@@ -63,7 +64,8 @@
     "make-error": "^1.3.5",
     "mkdirp": "^0.5.1",
     "semver": "^5.5.1",
-    "tslib": "^1.9.3"
+    "tslib": "^1.9.3",
+    "yargs-parser": "^10.1.0"
   },
   "peerDependencies": {
     "babel-jest": ">=22 <24",
@@ -86,6 +88,7 @@
     "@types/mkdirp": "^0.5.2",
     "@types/node": "^10.9.4",
     "@types/semver": "^5.5.0",
+    "@types/yargs": "^11.1.1",
     "conventional-changelog-cli": "^2.0.5",
     "cross-spawn": "^6.0.5",
     "doctoc": "^1.3.1",

src/cli/config/migrate.ts

@@ -0,0 +1,167 @@
+import { Logger } from 'bs-logger'
+import stringifyJson from 'fast-json-stable-stringify'
+import { existsSync } from 'fs'
+import { stringify as stringifyJson5 } from 'json5'
+import { basename, join } from 'path'
+import { Arguments } from 'yargs'
+
+import { CliCommand } from '..'
+import { createJestPreset } from '../../config/create-jest-preset'
+import { backportJestConfig } from '../../util/backports'
+
+export const run: CliCommand = async (args: Arguments, logger: Logger) => {
+  const file = args._[0]
+  const filePath = join(process.cwd(), file)
+  if (!existsSync(filePath)) {
+    throw new Error(`Configuration file ${file} does not exists.`)
+  }
+  const name = basename(file)
+  const isPackage = name === 'package.json'
+  if (!/\.(js|json)$/.test(name)) {
+    throw new TypeError(`Configuration file ${file} must be a JavaScript or JSON file.`)
+  }
+  let actualConfig: jest.InitialOptions = require(filePath)
+  if (isPackage) {
+    actualConfig = (actualConfig as any).jest
+  }
+  if (!actualConfig) actualConfig = {}
+
+  // migrate
+  // first we backport our options
+  const migratedConfig = backportJestConfig(logger, actualConfig)
+  // then we check if we can use `preset`
+  if (!migratedConfig.preset && args.jestPreset) {
+    migratedConfig.preset = 'ts-jest'
+  } else if (!args.jestPreset && migratedConfig.preset === 'ts-jest') {
+    delete migratedConfig.preset
+  }
+  const usesPreset = migratedConfig.preset === 'ts-jest'
+  const presets = createJestPreset({ allowJs: args.allowJs })
+
+  // check the extensions
+  if (migratedConfig.moduleFileExtensions && migratedConfig.moduleFileExtensions.length && usesPreset) {
+    const presetValue = dedupSort(presets.moduleFileExtensions).join('::')
+    const migratedValue = dedupSort(migratedConfig.moduleFileExtensions).join('::')
+    if (presetValue === migratedValue) {
+      delete migratedConfig.moduleFileExtensions
+    }
+  }
+  // check the testMatch
+  if (migratedConfig.testMatch && migratedConfig.testMatch.length && usesPreset) {
+    const presetValue = dedupSort(presets.testMatch).join('::')
+    const migratedValue = dedupSort(migratedConfig.testMatch).join('::')
+    if (presetValue === migratedValue) {
+      delete migratedConfig.testMatch
+    }
+  }
+
+  // migrate the transform
+  if (migratedConfig.transform) {
+    Object.keys(migratedConfig.transform).forEach(key => {
+      const val = (migratedConfig.transform as any)[key]
+      if (typeof val === 'string' && /\/?ts-jest(?:\/preprocessor\.js)?$/.test(val)) {
+        // tslint:disable-next-line:semicolon
+        ;(migratedConfig.transform as any)[key] = 'ts-jest'
+      }
+    })
+  }
+  // check if it's the same as the preset's one
+  if (
+    usesPreset &&
+    migratedConfig.transform &&
+    stringifyJson(migratedConfig.transform) === stringifyJson(presets.transform)
+  ) {
+    delete migratedConfig.transform
+  }
+
+  // cleanup
+  cleanupConfig(actualConfig)
+  cleanupConfig(migratedConfig)
+  const before = stringifyJson(actualConfig)
+  const after = stringifyJson(migratedConfig)
+  if (after === before) {
+    process.stderr.write(`
+No migration needed for given Jest configuration
+    `)
+    return
+  }
+
+  const stringify = /\.json$/.test(file) ? JSON.stringify : stringifyJson5
+  const footNotes: string[] = []
+
+  // if we are using preset, inform the user that he might be able to remove some section(s)
+  // we couldn't check for equality
+  //   if (usesPreset && migratedConfig.testMatch) {
+  //     footNotes.push(`
+  // I couldn't check if your "testMatch" value is the same as mine which is: ${stringify(
+  //       presets.testMatch,
+  //       undefined,
+  //       '  ',
+  //     )}
+  // If it is the case, you can safely remove the "testMatch" from what I've migrated.
+  // `)
+  //   }
+  if (usesPreset && migratedConfig.transform) {
+    footNotes.push(`
+I couldn't check if your "transform" value is the same as mine which is: ${stringify(
+      presets.transform,
+      undefined,
+      '  ',
+    )}
+If it is the case, you can safely remove the "transform" from what I've migrated.
+`)
+  }
+
+  // output new config
+  process.stderr.write(`
+Migrated Jest configuration:
+`)
+  process.stdout.write(`${stringify(migratedConfig, undefined, '  ')}\n`)
+  process.stderr.write(`
+${footNotes.join('\n')}
+`)
+}
+
+function cleanupConfig(config: jest.InitialOptions): void {
+  if (config.globals) {
+    if ((config as any).globals['ts-jest'] && Object.keys((config as any).globals['ts-jest']).length === 0) {
+      delete (config as any).globals['ts-jest']
+    }
+    if (Object.keys(config.globals).length === 0) {
+      delete config.globals
+    }
+  }
+  if (config.transform && Object.keys(config.transform).length === 0) {
+    delete config.transform
+  }
+  if (config.moduleFileExtensions) {
+    config.moduleFileExtensions = dedupSort(config.moduleFileExtensions)
+    if (config.moduleFileExtensions.length === 0) delete config.moduleFileExtensions
+  }
+  if (config.testMatch) {
+    config.testMatch = dedupSort(config.testMatch)
+    if (config.testMatch.length === 0) delete config.testMatch
+  }
+}
+
+function dedupSort(arr: any[]) {
+  return arr
+    .filter((s, i, a) => a.findIndex(e => s.toString() === e.toString()) === i)
+    .sort((a, b) => (a.toString() > b.toString() ? 1 : a.toString() < b.toString() ? -1 : 0))
+}
+
+export const help: CliCommand = async () => {
+  process.stdout.write(`
+Usage:
+  ts-jest config:migrate [options] <config-file>
+
+Arguments:
+  <config-file>         Can be a js or json Jest config file. If it is a
+                        package.json file, the configuration will be read from
+                        the "jest" property.
+
+Options:
+  --allow-js            TSJest will be used to process JS files as well
+  --no-jest-preset      Disable the use of Jest presets
+`)
+}

src/cli/help.ts

@@ -0,0 +1,17 @@
+import { Arguments } from 'yargs'
+
+export const run = async (_: Arguments) => {
+  process.stdout.write(`
+Usage:
+  ts-jest command [options] [...args]
+
+Commands:
+  help [command]        Show this help, or help about a command
+  config:migrate        Migrates a given Jest configuration
+
+Example:
+  ts-jest help config:migrate
+`)
+}
+
+export { run as help }

src/cli/index.ts

@@ -0,0 +1,41 @@
+import { LogContexts, Logger } from 'bs-logger'
+import { Arguments } from 'yargs'
+import yargsParser from 'yargs-parser'
+
+import { rootLogger } from '../util/logger'
+
+const VALID_COMMANDS = ['help', 'config:migrate']
+
+// tslint:disable-next-line:prefer-const
+let [, , ...args] = process.argv
+
+const logger = rootLogger.child({ [LogContexts.namespace]: 'cli', [LogContexts.application]: 'ts-jest' })
+
+const parsedArgv = yargsParser(args, {
+  boolean: ['dryRun', 'jestPreset', 'allowJs', 'diff'],
+  count: ['verbose'],
+  alias: { verbose: ['v'] },
+  default: { dryRun: false, jestPreset: true, allowJs: false, verbose: 0, diff: false },
+})
+let command = parsedArgv._.shift() as string
+const isHelp = command === 'help'
+if (isHelp) command = parsedArgv._.shift() as string
+
+if (!VALID_COMMANDS.includes(command)) command = 'help'
+
+export type CliCommand = (argv: Arguments, logger: Logger) => Promise<void>
+
+// tslint:disable-next-line:no-var-requires
+const { run, help }: { run: CliCommand; help: CliCommand } = require(`./${command.replace(/:/g, '/')}`)
+
+const cmd = isHelp && command !== 'help' ? help : run
+
+cmd(parsedArgv, logger).then(
+  () => {
+    process.exit(0)
+  },
+  (err: Error) => {
+    logger.fatal(err.message)
+    process.exit(1)
+  },
+)

src/config/create-jest-preset.ts

@@ -12,17 +12,21 @@ const defaults = jestConfig.defaults || {
   moduleFileExtensions: ['js', 'json', 'jsx', 'node'],
 }
 
-// TODO: find out if tsconfig that we'll use contains `allowJs`
-// and change the transform so that it also uses ts-jest for js files
-
-export function createJestPreset({ allowJs = false }: CreateJestPresetOptions = {}) {
+export function createJestPreset(
+  { allowJs = false }: CreateJestPresetOptions = {},
+  from: jest.InitialOptions = defaults,
+) {
   logger.debug({ allowJs }, 'creating jest presets', allowJs ? 'handling' : 'not handling', 'JavaScript files')
   return {
     transform: {
-      ...defaults.transform,
+      ...from.transform,
       [allowJs ? '^.+\\.[tj]sx?$' : '^.+\\.tsx?$']: 'ts-jest',
     },
-    testMatch: [...defaults.testMatch, '**/__tests__/**/*.ts?(x)', '**/?(*.)+(spec|test).ts?(x)'],
-    moduleFileExtensions: [...defaults.moduleFileExtensions, 'ts', 'tsx'],
+    testMatch: dedup([...from.testMatch, '**/__tests__/**/*.ts?(x)', '**/?(*.)+(spec|test).ts?(x)']),
+    moduleFileExtensions: dedup([...from.moduleFileExtensions, 'ts', 'tsx']),
   }
 }
+
+function dedup(array: string[]): string[] {
+  return array.filter((e, i, a) => a.indexOf(e) === i)
+}

src/shims.d.ts

@@ -17,3 +17,8 @@ declare module 'jest-config' {
 }
 
 declare module 'babel-core/lib/transformation/file'
+
+declare module 'yargs-parser' {
+  import yargs from 'yargs'
+  export = yargs.parse
+}