Extract existent inline requires to top level

packages/babel-jest/src/index.js

@@ -15,15 +15,15 @@ import crypto from 'crypto';
 import fs from 'fs';
 import path from 'path';
 import jestPreset from 'babel-preset-jest';
+import {transform as babelTransform, util as babelUtil} from 'babel-core';
+import babelIstanbulPlugin from 'babel-plugin-istanbul';
 
 const BABELRC_FILENAME = '.babelrc';
 const BABELRC_JS_FILENAME = '.babelrc.js';
 const BABEL_CONFIG_KEY = 'babel';
 const PACKAGE_JSON = 'package.json';
 const THIS_FILE = fs.readFileSync(__filename);
 
-let babel;
-
 const createTransformer = (options: any) => {
   const cache = Object.create(null);
 
@@ -98,11 +98,7 @@ const createTransformer = (options: any) => {
       config: ProjectConfig,
       transformOptions: TransformOptions,
     ): string {
-      if (!babel) {
-        babel = require('babel-core');
-      }
-
-      if (babel.util && !babel.util.canCompile(filename)) {
+      if (babelUtil && !babelUtil.canCompile(filename)) {
         return src;
       }
 
@@ -112,7 +108,7 @@ const createTransformer = (options: any) => {
         // Copied from jest-runtime transform.js
         theseOptions.plugins = theseOptions.plugins.concat([
           [
-            require('babel-plugin-istanbul').default,
+            babelIstanbulPlugin,
             {
               // files outside `cwd` will not be instrumented
               cwd: config.rootDir,
@@ -122,7 +118,7 @@ const createTransformer = (options: any) => {
         ]);
       }
 
-      return babel.transform(src, theseOptions).code;
+      return babelTransform(src, theseOptions).code;
     },
   };
 };

packages/jest-cli/src/TestRunner.js

@@ -29,6 +29,7 @@ import SummaryReporter from './reporters/SummaryReporter';
 import VerboseReporter from './reporters/VerboseReporter';
 import runTest from './runTest';
 import TestWatcher from './TestWatcher';
+import CoverageReporter from './reporters/CoverageReporter';
 import ReporterDispatcher from './ReporterDispatcher';
 
 const SLOW_TEST_TIME = 3000;
@@ -295,9 +296,6 @@ class TestRunner {
     }
 
     if (collectCoverage) {
-      // coverage reporter dependency graph is pretty big and we don't
-      // want to require it if we're not in the `--coverage` mode
-      const CoverageReporter = require('./reporters/CoverageReporter');
       this.addReporter(
         new CoverageReporter(this._globalConfig, {
           maxWorkers: this._options.maxWorkers,

packages/jest-cli/src/cli/getJest.js

@@ -13,6 +13,7 @@ import type {Path} from 'types/Config';
 import path from 'path';
 import chalk from 'chalk';
 import fs from 'graceful-fs';
+import jest from '../jest';
 
 function getJest(packageRoot: Path) {
   const packageJSONPath = path.join(packageRoot, 'package.json');
@@ -21,7 +22,6 @@ function getJest(packageRoot: Path) {
     /* $FlowFixMe */
     return require(binPath);
   } else {
-    const jest = require('../jest');
     // Check if Jest is specified in `package.json` but not installed.
     if (fs.existsSync(packageJSONPath)) {
       /* $FlowFixMe */

packages/jest-cli/src/reporters/CoverageReporter.js

@@ -31,6 +31,7 @@ import libSourceMaps from 'istanbul-lib-source-maps';
 import pify from 'pify';
 import workerFarm from 'worker-farm';
 import BaseReporter from './BaseReporter';
+import CoverageWorker from './CoverageWorker';
 
 const FAIL_COLOR = chalk.bold.red;
 const RUNNING_TEST_COLOR = chalk.bold.dim;
@@ -143,7 +144,7 @@ class CoverageReporter extends BaseReporter {
     let worker;
     let farm;
     if (this._maxWorkers <= 1) {
-      worker = pify(require('./CoverageWorker'));
+      worker = pify(CoverageWorker);
     } else {
       farm = workerFarm(
         {

packages/jest-config/src/deprecated.js

@@ -9,8 +9,9 @@
  */
 
 import chalk from 'chalk';
+import prettyFormat from 'pretty-format';
 
-const format = (value: mixed) => require('pretty-format')(value, {min: true});
+const format = (value: mixed) => prettyFormat(value, {min: true});
 
 const deprecatedOptions = {
   preprocessorIgnorePatterns: (options: {

packages/jest-environment-jsdom/src/index.js

@@ -14,6 +14,7 @@ import type {ModuleMocker} from 'jest-mock';
 
 import {FakeTimers, installCommonGlobals} from 'jest-util';
 import mock from 'jest-mock';
+import JSDom from 'jsdom';
 
 class JSDOMEnvironment {
   document: ?Object;
@@ -23,7 +24,7 @@ class JSDOMEnvironment {
 
   constructor(config: ProjectConfig): void {
     // lazy require
-    this.document = require('jsdom').jsdom(/* markup */ undefined, {
+    this.document = JSDom.jsdom(/* markup */ undefined, {
       url: config.testURL,
     });
     const global = (this.global = this.document.defaultView);
@@ -50,7 +51,7 @@ class JSDOMEnvironment {
 
   runScript(script: Script): ?any {
     if (this.global) {
-      return require('jsdom').evalVMScript(this.global, script);
+      return JSDom.evalVMScript(this.global, script);
     }
     return null;
   }

packages/jest-runtime/src/ScriptTransformer.js

@@ -20,6 +20,9 @@ import path from 'path';
 import vm from 'vm';
 import {createDirectory} from 'jest-util';
 import fs from 'graceful-fs';
+import {transform as babelTransform} from 'babel-core';
+import babelPluginIstanbul from 'babel-plugin-istanbul';
+import convertSourceMap from 'convert-source-map';
 // $FlowFixMe: Missing ESM export
 import {getCacheFilePath} from 'jest-haste-map';
 import stableStringify from 'json-stable-stringify';
@@ -148,12 +151,7 @@ class ScriptTransformer {
   }
 
   _instrumentFile(filename: Path, content: string): string {
-    // Keeping these requires inside this function reduces a single run
-    // time by 2sec if not running in `--coverage` mode
-    const babel = require('babel-core');
-    const babelPluginIstanbul = require('babel-plugin-istanbul').default;
-
-    return babel.transform(content, {
+    return babelTransform(content, {
       auxiliaryCommentBefore: ' istanbul ignore next ',
       babelrc: false,
       filename,
@@ -217,8 +215,7 @@ class ScriptTransformer {
 
     if (mapCoverage) {
       if (!transformed.map) {
-        const convert = require('convert-source-map');
-        const inlineSourceMap = convert.fromSource(transformed.code);
+        const inlineSourceMap = convertSourceMap.fromSource(transformed.code);
         if (inlineSourceMap) {
           transformed.map = inlineSourceMap.toJSON();
         }

packages/jest-runtime/src/index.js

@@ -25,6 +25,8 @@ import fs from 'graceful-fs';
 import stripBOM from 'strip-bom';
 import ScriptTransformer from './ScriptTransformer';
 import shouldInstrument from './shouldInstrument';
+import cli from './cli';
+import cliArgs from './cli/args';
 
 type Module = {|
   children?: Array<any>,
@@ -264,11 +266,11 @@ class Runtime {
   }
 
   static runCLI(args?: Argv, info?: Array<string>) {
-    return require('./cli').run(args, info);
+    return cli.run(args, info);
   }
 
   static getCLIOptions() {
-    return require('./cli/args').options;
+    return cliArgs.options;
   }
 
   requireModule(

packages/jest-validate/src/index.js

@@ -8,10 +8,14 @@
  * @flow
  */
 
+import {createDidYouMeanMessage, format, logValidationWarning} from './utils';
+import {ValidationError} from './errors';
+import validate from './validate';
+
 module.exports = {
-  ValidationError: require('./errors').ValidationError,
-  createDidYouMeanMessage: require('./utils').createDidYouMeanMessage,
-  format: require('./utils').format,
-  logValidationWarning: require('./utils').logValidationWarning,
-  validate: require('./validate'),
+  ValidationError,
+  createDidYouMeanMessage,
+  format,
+  logValidationWarning,
+  validate,
 };

packages/jest-validate/src/utils.js

@@ -9,6 +9,8 @@
  */
 
 import chalk from 'chalk';
+import prettyFormat from 'pretty-format';
+import leven from 'leven';
 
 const BULLET: string = chalk.bold('\u25cf');
 const DEPRECATION = `${BULLET} Deprecation Warning`;
@@ -18,7 +20,7 @@ const WARNING = `${BULLET} Validation Warning`;
 const format = (value: any): string =>
   typeof value === 'function'
     ? value.toString()
-    : require('pretty-format')(value, {min: true});
+    : prettyFormat(value, {min: true});
 
 class ValidationError extends Error {
   name: string;
@@ -46,7 +48,6 @@ const createDidYouMeanMessage = (
   unrecognized: string,
   allowedOptions: Array<string>,
 ) => {
-  const leven = require('leven');
   const suggestion = allowedOptions.find(option => {
     const steps: number = leven(option, unrecognized);
     return steps < 3;