diff --git a/integration_tests/__tests__/__snapshots__/showConfig-test.js.snap b/integration_tests/__tests__/__snapshots__/showConfig-test.js.snap
index 8b4a627a5406..7875beebe54d 100644
--- a/integration_tests/__tests__/__snapshots__/showConfig-test.js.snap
+++ b/integration_tests/__tests__/__snapshots__/showConfig-test.js.snap
@@ -72,9 +72,6 @@ exports[`jest --showConfig outputs config info and exits 1`] = `
     "mapCoverage": false,
     "noStackTrace": false,
     "notify": false,
-    "projects": [
-      "/mocked/root/path/jest/integration_tests/verbose_reporter"
-    ],
     "rootDir": "/mocked/root/path/jest/integration_tests/verbose_reporter",
     "testPathPattern": "",
     "testResultsProcessor": null,
diff --git a/packages/jest-cli/src/SearchSource.js b/packages/jest-cli/src/SearchSource.js
index cadf8989e770..a9782058d715 100644
--- a/packages/jest-cli/src/SearchSource.js
+++ b/packages/jest-cli/src/SearchSource.js
@@ -33,7 +33,7 @@ type Options = {|
   withAncestor?: boolean,
 |};
 
-export type PathPattern = {|
+export type PathPatternObject = {|
   input?: string,
   findRelatedTests?: boolean,
   lastCommit?: boolean,
@@ -216,13 +216,17 @@ class SearchSource {
     });
   }
 
-  getTestPaths(pattern: PathPattern): Promise<SearchResult> {
-    if (pattern.onlyChanged) {
-      return this.findChangedTests({lastCommit: pattern.lastCommit});
-    } else if (pattern.findRelatedTests && pattern.paths) {
-      return Promise.resolve(this.findRelatedTestsFromPattern(pattern.paths));
-    } else if (pattern.testPathPattern != null) {
-      return Promise.resolve(this.findMatchingTests(pattern.testPathPattern));
+  getTestPaths(patternObj: PathPatternObject): Promise<SearchResult> {
+    if (patternObj.onlyChanged) {
+      return this.findChangedTests({lastCommit: patternObj.lastCommit});
+    } else if (patternObj.findRelatedTests && patternObj.paths) {
+      return Promise.resolve(
+        this.findRelatedTestsFromPattern(patternObj.paths),
+      );
+    } else if (patternObj.testPathPattern != null) {
+      return Promise.resolve(
+        this.findMatchingTests(patternObj.testPathPattern),
+      );
     } else {
       return Promise.resolve({tests: []});
     }
diff --git a/packages/jest-cli/src/TestRunner.js b/packages/jest-cli/src/TestRunner.js
index 8f5317959cb8..f5e3a4c827ba 100644
--- a/packages/jest-cli/src/TestRunner.js
+++ b/packages/jest-cli/src/TestRunner.js
@@ -16,9 +16,14 @@ import type {
 import type {GlobalConfig, ReporterConfig} from 'types/Config';
 import type {Context} from 'types/Context';
 import type {Reporter, Test} from 'types/TestRunner';
-import type {PathPattern} from './SearchSource';
+import type {PathPatternObject} from './SearchSource';
 
 import {formatExecError} from 'jest-message-util';
+import {
+  addResult,
+  buildFailureTestResult,
+  makeEmptyAggregatedTestResult,
+} from './testResultHelpers';
 import snapshot from 'jest-snapshot';
 import pify from 'pify';
 import throat from 'throat';
@@ -43,7 +48,7 @@ class CancelRun extends Error {
 
 export type TestRunnerOptions = {|
   maxWorkers: number,
-  pattern: PathPattern,
+  pattern: PathPatternObject,
   startRun: () => *,
   testNamePattern: string,
   testPathPattern: string,
@@ -378,117 +383,11 @@ class TestRunner {
 }
 
 const createAggregatedResults = (numTotalTestSuites: number) => {
-  return {
-    numFailedTestSuites: 0,
-    numFailedTests: 0,
-    numPassedTestSuites: 0,
-    numPassedTests: 0,
-    numPendingTestSuites: 0,
-    numPendingTests: 0,
-    numRuntimeErrorTestSuites: 0,
-    numTotalTestSuites,
-    numTotalTests: 0,
-    snapshot: {
-      added: 0,
-      didUpdate: false, // is set only after the full run
-      failure: false,
-      filesAdded: 0,
-      // combines individual test results + results after full run
-      filesRemoved: 0,
-      filesUnmatched: 0,
-      filesUpdated: 0,
-      matched: 0,
-      total: 0,
-      unchecked: 0,
-      unmatched: 0,
-      updated: 0,
-    },
-    startTime: Date.now(),
-    success: false,
-    testResults: [],
-    wasInterrupted: false,
-  };
-};
-
-const addResult = (
-  aggregatedResults: AggregatedResult,
-  testResult: TestResult,
-): void => {
-  aggregatedResults.testResults.push(testResult);
-  aggregatedResults.numTotalTests +=
-    testResult.numPassingTests +
-    testResult.numFailingTests +
-    testResult.numPendingTests;
-  aggregatedResults.numFailedTests += testResult.numFailingTests;
-  aggregatedResults.numPassedTests += testResult.numPassingTests;
-  aggregatedResults.numPendingTests += testResult.numPendingTests;
-
-  if (testResult.testExecError) {
-    aggregatedResults.numRuntimeErrorTestSuites++;
-  }
-
-  if (testResult.skipped) {
-    aggregatedResults.numPendingTestSuites++;
-  } else if (testResult.numFailingTests > 0 || testResult.testExecError) {
-    aggregatedResults.numFailedTestSuites++;
-  } else {
-    aggregatedResults.numPassedTestSuites++;
-  }
-
-  // Snapshot data
-  if (testResult.snapshot.added) {
-    aggregatedResults.snapshot.filesAdded++;
-  }
-  if (testResult.snapshot.fileDeleted) {
-    aggregatedResults.snapshot.filesRemoved++;
-  }
-  if (testResult.snapshot.unmatched) {
-    aggregatedResults.snapshot.filesUnmatched++;
-  }
-  if (testResult.snapshot.updated) {
-    aggregatedResults.snapshot.filesUpdated++;
-  }
-
-  aggregatedResults.snapshot.added += testResult.snapshot.added;
-  aggregatedResults.snapshot.matched += testResult.snapshot.matched;
-  aggregatedResults.snapshot.unchecked += testResult.snapshot.unchecked;
-  aggregatedResults.snapshot.unmatched += testResult.snapshot.unmatched;
-  aggregatedResults.snapshot.updated += testResult.snapshot.updated;
-  aggregatedResults.snapshot.total +=
-    testResult.snapshot.added +
-    testResult.snapshot.matched +
-    testResult.snapshot.unmatched +
-    testResult.snapshot.updated;
-};
-
-const buildFailureTestResult = (
-  testPath: string,
-  err: TestError,
-): TestResult => {
-  return {
-    console: null,
-    failureMessage: null,
-    numFailingTests: 0,
-    numPassingTests: 0,
-    numPendingTests: 0,
-    perfStats: {
-      end: 0,
-      start: 0,
-    },
-    skipped: false,
-    snapshot: {
-      added: 0,
-      fileDeleted: false,
-      matched: 0,
-      unchecked: 0,
-      unmatched: 0,
-      updated: 0,
-    },
-    sourceMaps: {},
-    testExecError: err,
-    testFilePath: testPath,
-    testResults: [],
-  };
+  const result = makeEmptyAggregatedTestResult();
+  result.numTotalTestSuites = numTotalTestSuites;
+  result.startTime = Date.now();
+  result.success = false;
+  return result;
 };
 
 const getEstimatedTime = (timings, workers) => {
diff --git a/packages/jest-cli/src/cli/index.js b/packages/jest-cli/src/cli/index.js
index 1b5d4d718ccc..5b4a8d0a6045 100644
--- a/packages/jest-cli/src/cli/index.js
+++ b/packages/jest-cli/src/cli/index.js
@@ -8,17 +8,92 @@
  * @flow
  */
 
-import type {Path} from 'types/Config';
+import type {AggregatedResult} from 'types/TestResult';
 import type {Argv} from 'types/Argv';
+import type {GlobalConfig, Path, ProjectConfig} from 'types/Config';
 
-import {validateCLIOptions} from 'jest-util';
-import yargs from 'yargs';
+import {
+  Console,
+  clearLine,
+  createDirectory,
+  validateCLIOptions,
+} from 'jest-util';
+import {readConfig} from 'jest-config';
+import {version as VERSION} from '../../package.json';
 import args from './args';
+import chalk from 'chalk';
+import createContext from '../lib/createContext';
 import getJest from './getJest';
-import runCLI from './runCLI';
+import getMaxWorkers from '../lib/getMaxWorkers';
+import handleDeprecationWarnings from '../lib/handleDeprecationWarnings';
+import logDebugMessages from '../lib/logDebugMessages';
+import preRunMessage from '../preRunMessage';
+import runJest from '../runJest';
+import Runtime from 'jest-runtime';
+import TestWatcher from '../TestWatcher';
+import watch from '../watch';
+import yargs from 'yargs';
+
+function run(maybeArgv?: Argv, project?: Path) {
+  const argv: Argv = _buildArgv(maybeArgv, project);
+  const projects = _getProjectListFromCLIArgs(argv, project);
+  // If we're running a single Jest project, we might want to use another
+  // version of Jest (the one that is specified in this project's package.json)
+  const runCLIFn = _getRunCLIFn(projects);
+
+  runCLIFn(argv, projects, result => _readResultsAndExit(argv, result));
+}
+
+const runCLI = async (
+  argv: Argv,
+  projects: Array<Path>,
+  onComplete: (results: ?AggregatedResult) => void,
+) => {
+  // Optimize 'fs' module and make it more compatible with multiple platforms.
+  _patchGlobalFSModule();
 
-function run(argv?: Argv, project?: Path) {
-  argv = yargs(argv || process.argv.slice(2))
+  // If we output a JSON object, we can't write anything to stdout, since
+  // it'll break the JSON structure and it won't be valid.
+  const outputStream = argv.json ? process.stderr : process.stdout;
+
+  argv.version && _printVersionAndExit(outputStream, onComplete);
+
+  try {
+    const {globalConfig, configs, hasDeprecationWarnings} = _getConfigs(
+      projects,
+      argv,
+      outputStream,
+    );
+    await _run(
+      globalConfig,
+      configs,
+      hasDeprecationWarnings,
+      outputStream,
+      argv,
+      onComplete,
+    );
+  } catch (error) {
+    _printErrorAndExit(error);
+  }
+};
+
+const _printErrorAndExit = error => {
+  clearLine(process.stderr);
+  clearLine(process.stdout);
+  console.error(chalk.red(error.stack));
+  process.exit(1);
+};
+
+const _readResultsAndExit = (argv: Argv, result: ?AggregatedResult) => {
+  const code = !result || result.success ? 0 : 1;
+  process.on('exit', () => process.exit(code));
+  if (argv && argv.forceExit) {
+    process.exit(code);
+  }
+};
+
+const _buildArgv = (maybeArgv: ?Argv, project: ?Path) => {
+  const argv: Argv = yargs(maybeArgv || process.argv.slice(2))
     .usage(args.usage)
     .help()
     .alias('help', 'h')
@@ -28,23 +103,226 @@ function run(argv?: Argv, project?: Path) {
 
   validateCLIOptions(argv, args.options);
 
-  if (!project) {
-    project = process.cwd();
+  return argv;
+};
+
+const _getProjectListFromCLIArgs = (argv, project: ?Path) => {
+  const projects = argv.projects ? argv.projects : [];
+
+  if (project) {
+    projects.push(project);
+  }
+
+  if (!projects.length) {
+    projects.push(process.cwd());
+  }
+
+  return projects;
+};
+
+const _getRunCLIFn = (projects: Array<Path>) =>
+  projects.length === 1 ? getJest(projects[0]).runCLI : runCLI;
+
+const _printDebugInfoAndExitIfNeeded = (
+  argv,
+  globalConfig,
+  config,
+  outputStream,
+) => {
+  if (argv.debug || argv.showConfig) {
+    logDebugMessages(globalConfig, config, outputStream);
+  }
+  if (argv.showConfig) {
+    process.exit(0);
+  }
+};
+
+const _printVersionAndExit = (outputStream, onComplete) => {
+  outputStream.write(`v${VERSION}\n`);
+  onComplete && onComplete();
+  return;
+};
+
+// Possible scenarios:
+//  1. jest --config config.json
+//  2. jest --projects p1 p2
+//  3. jest --projects p1 p2 --config config.json
+//  4. jest --projects p1
+//  5. jest
+//
+// If no projects are specified, process.cwd() will be used as the default
+// (and only) project.
+const _getConfigs = (
+  projectsFromCLIArgs: Array<Path>,
+  argv: Argv,
+  outputStream,
+): {
+  globalConfig: GlobalConfig,
+  configs: Array<ProjectConfig>,
+  hasDeprecationWarnings: boolean,
+} => {
+  let globalConfig;
+  let hasDeprecationWarnings;
+  let configs: Array<ProjectConfig> = [];
+  let projects = projectsFromCLIArgs;
+
+  if (projectsFromCLIArgs.length === 1) {
+    const parsedConfig = readConfig(argv, projects[0]);
+
+    if (parsedConfig.globalConfig.projects) {
+      // If this was a single project, and its config has `projects`
+      // settings, use that value instead.
+      projects = parsedConfig.globalConfig.projects;
+    }
+
+    hasDeprecationWarnings = parsedConfig.hasDeprecationWarnings;
+    globalConfig = parsedConfig.globalConfig;
+    configs = [parsedConfig.config];
+    if (globalConfig.projects && globalConfig.projects.length) {
+      // Even though we had one project in CLI args, there might be more
+      // projects defined in the config.
+      projects = globalConfig.projects;
+    }
+  }
+
+  if (projects.length > 1) {
+    const parsedConfigs = projects.map(root => readConfig(argv, root));
+    configs = parsedConfigs.map(({config}) => config);
+    if (!hasDeprecationWarnings) {
+      hasDeprecationWarnings = parsedConfigs.some(
+        ({hasDeprecationWarnings}) => !!hasDeprecationWarnings,
+      );
+    }
+    // If no config was passed initially, use the one from the first project
+    if (!globalConfig) {
+      globalConfig = parsedConfigs[0].globalConfig;
+    }
   }
 
-  if (!argv.projects) {
-    argv.projects = [project];
+  if (!globalConfig || !configs.length) {
+    throw new Error('jest: No configuration found for any project.');
   }
 
-  const execute = argv.projects.length === 1 ? getJest(project).runCLI : runCLI;
-  execute(argv, argv.projects, result => {
-    const code = !result || result.success ? 0 : 1;
-    process.on('exit', () => process.exit(code));
-    if (argv && argv.forceExit) {
-      process.exit(code);
+  _printDebugInfoAndExitIfNeeded(argv, globalConfig, configs[0], outputStream);
+
+  return {
+    configs,
+    globalConfig,
+    hasDeprecationWarnings: !!hasDeprecationWarnings,
+  };
+};
+
+const _patchGlobalFSModule = () => {
+  const realFs = require('fs');
+  const fs = require('graceful-fs');
+  fs.gracefulify(realFs);
+};
+
+const _buildContextsAndHasteMaps = async (
+  configs,
+  globalConfig,
+  outputStream,
+  argv,
+) => {
+  const hasteMapInstances = Array(configs.length);
+  const contexts = await Promise.all(
+    configs.map(async (config, index) => {
+      createDirectory(config.cacheDirectory);
+      const hasteMapInstance = Runtime.createHasteMap(config, {
+        console: new Console(outputStream, outputStream),
+        maxWorkers: getMaxWorkers(argv),
+        resetCache: !config.cache,
+        watch: globalConfig.watch,
+        watchman: globalConfig.watchman,
+      });
+      hasteMapInstances[index] = hasteMapInstance;
+      return createContext(config, await hasteMapInstance.build());
+    }),
+  );
+
+  return {contexts, hasteMapInstances};
+};
+
+const _run = async (
+  globalConfig,
+  configs,
+  hasDeprecationWarnings,
+  outputStream,
+  argv,
+  onComplete,
+) => {
+  const {contexts, hasteMapInstances} = await _buildContextsAndHasteMaps(
+    configs,
+    globalConfig,
+    outputStream,
+    argv,
+  );
+
+  argv.watch || argv.watchAll
+    ? _runWatch(
+        argv,
+        contexts,
+        configs,
+        hasDeprecationWarnings,
+        globalConfig,
+        outputStream,
+        hasteMapInstances,
+      )
+    : _runWithoutWatch(globalConfig, contexts, argv, outputStream, onComplete);
+};
+
+const _runWatch = async (
+  argv,
+  contexts,
+  configs,
+  hasDeprecationWarnings,
+  globalConfig,
+  outputStream,
+  hasteMapInstances,
+) => {
+  if (hasDeprecationWarnings) {
+    try {
+      await handleDeprecationWarnings(outputStream, process.stdin);
+      return watch(
+        globalConfig,
+        contexts,
+        argv,
+        outputStream,
+        hasteMapInstances,
+      );
+    } catch (e) {
+      process.exit(0);
     }
-  });
-}
+  }
+
+  return watch(globalConfig, contexts, argv, outputStream, hasteMapInstances);
+};
+
+const _runWithoutWatch = async (
+  globalConfig,
+  contexts,
+  argv,
+  outputStream,
+  onComplete,
+) => {
+  const startRun = () => {
+    if (!argv.listTests) {
+      preRunMessage.print(outputStream);
+    }
+    runJest(
+      globalConfig,
+      contexts,
+      argv,
+      outputStream,
+      new TestWatcher({isWatchMode: false}),
+      startRun,
+      onComplete,
+    );
+  };
+  return startRun();
+};
 
-exports.run = run;
-exports.runCLI = runCLI;
+module.exports = {
+  run,
+  runCLI,
+};
diff --git a/packages/jest-cli/src/cli/runCLI.js b/packages/jest-cli/src/cli/runCLI.js
deleted file mode 100644
index 62e93ef97d90..000000000000
--- a/packages/jest-cli/src/cli/runCLI.js
+++ /dev/null
@@ -1,136 +0,0 @@
-/**
- * Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree. An additional grant
- * of patent rights can be found in the PATENTS file in the same directory.
- *
- * @flow
- */
-
-import type {Argv} from 'types/Argv';
-import type {AggregatedResult} from 'types/TestResult';
-import type {Path} from 'types/Config';
-
-import Runtime from 'jest-runtime';
-import {Console, clearLine, createDirectory} from 'jest-util';
-import {readConfig} from 'jest-config';
-import chalk from 'chalk';
-import createContext from '../lib/createContext';
-import getMaxWorkers from '../lib/getMaxWorkers';
-import handleDeprecationWarnings from '../lib/handleDeprecationWarnings';
-import logDebugMessages from '../lib/logDebugMessages';
-import preRunMessage from '../preRunMessage';
-import runJest from '../runJest';
-import TestWatcher from '../TestWatcher';
-import watch from '../watch';
-import {version as VERSION} from '../../package.json';
-
-module.exports = async (
-  argv: Argv,
-  projects: Array<Path>,
-  onComplete: (results: ?AggregatedResult) => void,
-) => {
-  const realFs = require('fs');
-  const fs = require('graceful-fs');
-  fs.gracefulify(realFs);
-
-  const pipe = argv.json ? process.stderr : process.stdout;
-  if (argv.version) {
-    pipe.write(`v${VERSION}\n`);
-    onComplete && onComplete();
-    return;
-  }
-
-  const _run = async (globalConfig, configs) => {
-    const hasteMapInstances = Array(configs.length);
-    const contexts = await Promise.all(
-      configs.map(async ({config}, index) => {
-        createDirectory(config.cacheDirectory);
-        const hasteMapInstance = Runtime.createHasteMap(config, {
-          console: new Console(pipe, pipe),
-          maxWorkers: getMaxWorkers(argv),
-          resetCache: !config.cache,
-          watch: globalConfig.watch,
-          watchman: globalConfig.watchman,
-        });
-        hasteMapInstances[index] = hasteMapInstance;
-        return createContext(config, await hasteMapInstance.build());
-      }),
-    );
-
-    if (argv.watch || argv.watchAll) {
-      if (configs.some(({hasDeprecationWarnings}) => hasDeprecationWarnings)) {
-        try {
-          await handleDeprecationWarnings(pipe, process.stdin);
-          return watch(globalConfig, contexts, argv, pipe, hasteMapInstances);
-        } catch (e) {
-          process.exit(0);
-        }
-      }
-
-      return watch(globalConfig, contexts, argv, pipe, hasteMapInstances);
-    } else {
-      const startRun = () => {
-        if (!argv.listTests) {
-          preRunMessage.print(pipe);
-        }
-        runJest(
-          globalConfig,
-          contexts,
-          argv,
-          pipe,
-          new TestWatcher({isWatchMode: false}),
-          startRun,
-          onComplete,
-        );
-      };
-      return startRun();
-    }
-  };
-
-  try {
-    let globalConfig;
-    let hasDeprecationWarnings;
-    let configs = [];
-    let config;
-    if (projects.length === 1) {
-      ({config, globalConfig, hasDeprecationWarnings} = readConfig(
-        argv,
-        projects[0],
-      ));
-      configs = [{config, globalConfig, hasDeprecationWarnings}];
-      if (globalConfig.projects && globalConfig.projects.length) {
-        projects = globalConfig.projects;
-      }
-    }
-
-    if (projects.length > 1) {
-      configs = projects.map(root => readConfig(argv, root));
-      // If no config was passed initially, use the one from the first project
-      if (!globalConfig && !config) {
-        globalConfig = configs[0].globalConfig;
-        config = configs[0].config;
-      }
-    }
-
-    if (!config || !globalConfig || !configs.length) {
-      throw new Error('jest: No configuration found for any project.');
-    }
-
-    if (argv.debug || argv.showConfig) {
-      logDebugMessages(globalConfig, config, pipe);
-    }
-
-    if (argv.showConfig) {
-      process.exit(0);
-    }
-
-    await _run(globalConfig, configs);
-  } catch (error) {
-    clearLine(process.stderr);
-    clearLine(process.stdout);
-    console.error(chalk.red(error.stack));
-    process.exit(1);
-  }
-};
diff --git a/packages/jest-cli/src/lib/getTestPathPattern.js b/packages/jest-cli/src/lib/getTestPathPattern.js
index 6463e726f66d..1e62be9125b3 100644
--- a/packages/jest-cli/src/lib/getTestPathPattern.js
+++ b/packages/jest-cli/src/lib/getTestPathPattern.js
@@ -9,7 +9,7 @@
  */
 
 import type {Argv} from 'types/Argv';
-import type {PathPattern} from '../SearchSource';
+import type {PathPatternObject} from '../SearchSource';
 
 import {clearLine} from 'jest-util';
 import chalk from 'chalk';
@@ -32,7 +32,7 @@ const showTestPathPatternError = (testPathPattern: string) => {
   );
 };
 
-module.exports = (argv: Argv): PathPattern => {
+module.exports = (argv: Argv): PathPatternObject => {
   if (argv.onlyChanged) {
     return {
       input: '',
diff --git a/packages/jest-cli/src/lib/logDebugMessages.js b/packages/jest-cli/src/lib/logDebugMessages.js
index ab06e8ebee32..eb967c9396a3 100644
--- a/packages/jest-cli/src/lib/logDebugMessages.js
+++ b/packages/jest-cli/src/lib/logDebugMessages.js
@@ -16,7 +16,7 @@ import {version as VERSION} from '../../package.json';
 const logDebugMessages = (
   globalConfig: GlobalConfig,
   config: ProjectConfig,
-  pipe: stream$Writable | tty$WriteStream,
+  outputStream: stream$Writable | tty$WriteStream,
 ): void => {
   /* $FlowFixMe */
   const testFramework = (require(config.testRunner): TestFramework);
@@ -26,7 +26,7 @@ const logDebugMessages = (
     globalConfig,
     version: VERSION,
   };
-  pipe.write(JSON.stringify(output, null, '  ') + '\n');
+  outputStream.write(JSON.stringify(output, null, '  ') + '\n');
 };
 
 module.exports = logDebugMessages;
diff --git a/packages/jest-cli/src/reporters/SummaryReporter.js b/packages/jest-cli/src/reporters/SummaryReporter.js
index dd4e7e3d7708..71904be8966d 100644
--- a/packages/jest-cli/src/reporters/SummaryReporter.js
+++ b/packages/jest-cli/src/reporters/SummaryReporter.js
@@ -12,8 +12,8 @@ import type {AggregatedResult, SnapshotSummary} from 'types/TestResult';
 import type {GlobalConfig} from 'types/Config';
 import type {Context} from 'types/Context';
 import type {ReporterOnStartOptions} from 'types/Reporters';
-import type {PathPattern} from '../SearchSource';
 import type {TestRunnerOptions} from '../TestRunner';
+import type {PathPatternObject} from '../SearchSource';
 
 import chalk from 'chalk';
 import BaseReporter from './BaseReporter';
@@ -246,13 +246,15 @@ class SummaryReporter extends BaseReporter {
 
   _getTestSummary(
     contexts: Set<Context>,
-    pattern: PathPattern,
+    patternObj: PathPatternObject,
     testNamePattern: string,
     testPathPattern: string,
   ) {
-    const testInfo = pattern.onlyChanged
+    const testInfo = patternObj.onlyChanged
       ? chalk.dim(' related to changed files')
-      : pattern.input !== '' ? chalk.dim(' matching ') + testPathPattern : '';
+      : patternObj.input !== ''
+          ? chalk.dim(' matching ') + testPathPattern
+          : '';
 
     const nameInfo = testNamePattern
       ? chalk.dim(' with tests matching ') + `"${testNamePattern}"`
diff --git a/packages/jest-cli/src/runJest.js b/packages/jest-cli/src/runJest.js
index 1d656b817fa6..495a60d00491 100644
--- a/packages/jest-cli/src/runJest.js
+++ b/packages/jest-cli/src/runJest.js
@@ -11,6 +11,7 @@
 import type {Argv} from 'types/Argv';
 import type {Context} from 'types/Context';
 import type {GlobalConfig} from 'types/Config';
+import type {PathPatternObject} from './SearchSource';
 import type {AggregatedResult} from 'types/TestResult';
 import type TestWatcher from './TestWatcher';
 
@@ -24,6 +25,7 @@ import SearchSource from './SearchSource';
 import updateArgv from './lib/updateArgv';
 import TestRunner from './TestRunner';
 import TestSequencer from './TestSequencer';
+import {makeEmptyAggregatedTestResult} from './testResultHelpers';
 
 const setConfig = (contexts, newConfig) =>
   contexts.forEach(
@@ -97,7 +99,13 @@ const getNoTestsFoundMessage = (testRunData, pattern) => {
   );
 };
 
-const getTestPaths = async (globalConfig, context, pattern, argv, pipe) => {
+const getTestPaths = async (
+  globalConfig,
+  context,
+  pattern,
+  argv,
+  outputStream,
+) => {
   const source = new SearchSource(context);
   let data = await source.getTestPaths(pattern);
   if (!data.tests.length) {
@@ -108,7 +116,7 @@ const getTestPaths = async (globalConfig, context, pattern, argv, pipe) => {
         pattern = getTestPathPattern(argv);
         data = await source.getTestPaths(pattern);
       } else {
-        new Console(pipe, pipe).log(
+        new Console(outputStream, outputStream).log(
           'Jest can only find uncommitted changed files in a git or hg ' +
             'repository. If you make your project a git or hg ' +
             'repository (`git init` or `hg init`), Jest will be able ' +
@@ -149,13 +157,23 @@ const runJest = async (
   globalConfig: GlobalConfig,
   contexts: Array<Context>,
   argv: Argv,
-  pipe: stream$Writable | tty$WriteStream,
+  outputStream: stream$Writable | tty$WriteStream,
   testWatcher: TestWatcher,
   startRun: () => *,
   onComplete: (testResults: AggregatedResult) => any,
+  // We use this internaly at FB. Since we run multiple processes and most
+  // of them don't match any tests, we don't want to print 'no tests found'
+  // message for all of them.
+  // This will no longer be needed when we complete this:
+  // https://github.com/facebook/jest/issues/3768
+  printNoTestsMessage?: (
+    outputStream: stream$Writable,
+    testRunData: Array<*>,
+    patternObj: PathPatternObject,
+  ) => void,
 ) => {
   const maxWorkers = getMaxWorkers(argv);
-  const pattern = getTestPathPattern(argv);
+  const patternObj = getTestPathPattern(argv);
   const sequencer = new TestSequencer();
   let allTests = [];
   const testRunData = await Promise.all(
@@ -163,9 +181,9 @@ const runJest = async (
       const matches = await getTestPaths(
         globalConfig,
         context,
-        pattern,
+        patternObj,
         argv,
-        pipe,
+        outputStream,
       );
       allTests = allTests.concat(matches.tests);
       return {context, matches};
@@ -176,41 +194,18 @@ const runJest = async (
 
   if (argv.listTests) {
     console.log(JSON.stringify(allTests.map(test => test.path)));
-    onComplete &&
-      onComplete({
-        numFailedTestSuites: 0,
-        numFailedTests: 0,
-        numPassedTestSuites: 0,
-        numPassedTests: 0,
-        numPendingTestSuites: 0,
-        numPendingTests: 0,
-        numRuntimeErrorTestSuites: 0,
-        numTotalTestSuites: 0,
-        numTotalTests: 0,
-        snapshot: {
-          added: 0,
-          didUpdate: false,
-          failure: false,
-          filesAdded: 0,
-          filesRemoved: 0,
-          filesUnmatched: 0,
-          filesUpdated: 0,
-          matched: 0,
-          total: 0,
-          unchecked: 0,
-          unmatched: 0,
-          updated: 0,
-        },
-        startTime: 0,
-        success: true,
-        testResults: [],
-        wasInterrupted: false,
-      });
+    onComplete && onComplete(makeEmptyAggregatedTestResult());
     return null;
   }
 
   if (!allTests.length) {
-    new Console(pipe, pipe).log(getNoTestsFoundMessage(testRunData, pattern));
+    if (printNoTestsMessage) {
+      printNoTestsMessage(outputStream, testRunData, patternObj);
+    } else {
+      new Console(outputStream, outputStream).log(
+        getNoTestsFoundMessage(testRunData, patternObj),
+      );
+    }
   } else if (
     allTests.length === 1 &&
     globalConfig.silent !== true &&
@@ -230,10 +225,10 @@ const runJest = async (
 
   const results = await new TestRunner(globalConfig, {
     maxWorkers,
-    pattern,
+    pattern: patternObj,
     startRun,
     testNamePattern: argv.testNamePattern,
-    testPathPattern: formatTestPathPattern(pattern),
+    testPathPattern: formatTestPathPattern(patternObj),
   }).runTests(allTests, testWatcher);
 
   sequencer.cacheResults(allTests, results);
diff --git a/packages/jest-cli/src/testResultHelpers.js b/packages/jest-cli/src/testResultHelpers.js
new file mode 100644
index 000000000000..80738c26f82d
--- /dev/null
+++ b/packages/jest-cli/src/testResultHelpers.js
@@ -0,0 +1,136 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @flow
+ */
+
+import type {
+  AggregatedResult,
+  SerializableError,
+  TestResult,
+} from 'types/TestResult';
+
+const makeEmptyAggregatedTestResult = (): AggregatedResult => {
+  return {
+    numFailedTestSuites: 0,
+    numFailedTests: 0,
+    numPassedTestSuites: 0,
+    numPassedTests: 0,
+    numPendingTestSuites: 0,
+    numPendingTests: 0,
+    numRuntimeErrorTestSuites: 0,
+    numTotalTestSuites: 0,
+    numTotalTests: 0,
+    snapshot: {
+      added: 0,
+      didUpdate: false, // is set only after the full run
+      failure: false,
+      filesAdded: 0,
+      // combines individual test results + removed files after the full run
+      filesRemoved: 0,
+      filesUnmatched: 0,
+      filesUpdated: 0,
+      matched: 0,
+      total: 0,
+      unchecked: 0,
+      unmatched: 0,
+      updated: 0,
+    },
+    startTime: 0,
+    success: true,
+    testResults: [],
+    wasInterrupted: false,
+  };
+};
+
+const buildFailureTestResult = (
+  testPath: string,
+  err: SerializableError,
+): TestResult => {
+  return {
+    console: null,
+    failureMessage: null,
+    numFailingTests: 0,
+    numPassingTests: 0,
+    numPendingTests: 0,
+    perfStats: {
+      end: 0,
+      start: 0,
+    },
+    skipped: false,
+    snapshot: {
+      added: 0,
+      fileDeleted: false,
+      matched: 0,
+      unchecked: 0,
+      unmatched: 0,
+      updated: 0,
+    },
+    sourceMaps: {},
+    testExecError: err,
+    testFilePath: testPath,
+    testResults: [],
+  };
+};
+
+// Add individual test result to an aggregated test result
+const addResult = (
+  aggregatedResults: AggregatedResult,
+  testResult: TestResult,
+): void => {
+  aggregatedResults.testResults.push(testResult);
+  aggregatedResults.numTotalTests +=
+    testResult.numPassingTests +
+    testResult.numFailingTests +
+    testResult.numPendingTests;
+  aggregatedResults.numFailedTests += testResult.numFailingTests;
+  aggregatedResults.numPassedTests += testResult.numPassingTests;
+  aggregatedResults.numPendingTests += testResult.numPendingTests;
+
+  if (testResult.testExecError) {
+    aggregatedResults.numRuntimeErrorTestSuites++;
+  }
+
+  if (testResult.skipped) {
+    aggregatedResults.numPendingTestSuites++;
+  } else if (testResult.numFailingTests > 0 || testResult.testExecError) {
+    aggregatedResults.numFailedTestSuites++;
+  } else {
+    aggregatedResults.numPassedTestSuites++;
+  }
+
+  // Snapshot data
+  if (testResult.snapshot.added) {
+    aggregatedResults.snapshot.filesAdded++;
+  }
+  if (testResult.snapshot.fileDeleted) {
+    aggregatedResults.snapshot.filesRemoved++;
+  }
+  if (testResult.snapshot.unmatched) {
+    aggregatedResults.snapshot.filesUnmatched++;
+  }
+  if (testResult.snapshot.updated) {
+    aggregatedResults.snapshot.filesUpdated++;
+  }
+
+  aggregatedResults.snapshot.added += testResult.snapshot.added;
+  aggregatedResults.snapshot.matched += testResult.snapshot.matched;
+  aggregatedResults.snapshot.unchecked += testResult.snapshot.unchecked;
+  aggregatedResults.snapshot.unmatched += testResult.snapshot.unmatched;
+  aggregatedResults.snapshot.updated += testResult.snapshot.updated;
+  aggregatedResults.snapshot.total +=
+    testResult.snapshot.added +
+    testResult.snapshot.matched +
+    testResult.snapshot.unmatched +
+    testResult.snapshot.updated;
+};
+
+module.exports = {
+  addResult,
+  buildFailureTestResult,
+  makeEmptyAggregatedTestResult,
+};