diff --git a/CHANGELOG.md b/CHANGELOG.md
index 90d3ba8bc6ff..8736f4bb5946 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -74,6 +74,7 @@
 - `[jest-runner]`: Migrate to TypeScript ([#7968](https://github.com/facebook/jest/pull/7968))
 - `[jest-runtime]`: Migrate to TypeScript ([#7964](https://github.com/facebook/jest/pull/7964), [#7988](https://github.com/facebook/jest/pull/7988))
 - `[@jest/fake-timers]`: Extract FakeTimers class from `jest-util` into a new separate package ([#7987](https://github.com/facebook/jest/pull/7987))
+- `[@jest/reporters]`: Migrate to TypeScript ([#7994](https://github.com/facebook/jest/pull/7994))
 - `[jest-repl]`: Migrate to TypeScript ([#8000](https://github.com/facebook/jest/pull/8000))
 - `[jest-validate]`: Migrate to TypeScript ([#7991](https://github.com/facebook/jest/pull/7991))
 - `[docs]`: Update CONTRIBUTING.md to add information about running jest with `jest-circus` locally ([#8013](https://github.com/facebook/jest/pull/8013)).
diff --git a/packages/jest-reporters/package.json b/packages/jest-reporters/package.json
index fceb1f9e0de0..39ff7a54f21d 100644
--- a/packages/jest-reporters/package.json
+++ b/packages/jest-reporters/package.json
@@ -3,8 +3,11 @@
   "description": "Jest's reporters",
   "version": "24.1.0",
   "main": "build/index.js",
+  "types": "build/index.d.ts",
   "dependencies": {
+    "@jest/environment": "^24.1.0",
     "@jest/transform": "^24.1.0",
+    "@jest/types": "^24.1.0",
     "chalk": "^2.0.1",
     "exit": "^0.1.2",
     "glob": "^7.1.2",
@@ -12,19 +15,21 @@
     "istanbul-lib-coverage": "^2.0.2",
     "istanbul-lib-instrument": "^3.0.1",
     "istanbul-lib-source-maps": "^3.0.1",
+    "jest-haste-map": "^24.0.0",
+    "jest-resolve": "^24.1.0",
+    "jest-runtime": "^24.1.0",
     "jest-util": "^24.0.0",
     "jest-worker": "^24.0.0",
     "node-notifier": "^5.2.1",
     "slash": "^2.0.0",
+    "source-map": "^0.6.0",
     "string-length": "^2.0.0"
   },
   "devDependencies": {
     "@types/exit": "^0.1.30",
     "@types/glob": "^7.1.1",
-    "@types/istanbul-lib-coverage": "^1.1.0",
     "@types/istanbul-lib-instrument": "^1.7.2",
     "@types/istanbul-lib-source-maps": "^1.2.1",
-    "@types/node-notifier": "^0.0.28",
     "@types/slash": "^2.0.0",
     "@types/string-length": "^2.0.0",
     "strip-ansi": "^5.0.0"
diff --git a/packages/jest-reporters/src/Status.js b/packages/jest-reporters/src/Status.ts
similarity index 76%
rename from packages/jest-reporters/src/Status.js
rename to packages/jest-reporters/src/Status.ts
index 6dbb87f73d6b..099dbe200739 100644
--- a/packages/jest-reporters/src/Status.js
+++ b/packages/jest-reporters/src/Status.ts
@@ -3,16 +3,13 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
- * @flow
  */
 
-import type {AggregatedResult, TestResult} from 'types/TestResult';
-import type {ProjectConfig, Path} from 'types/Config';
-import type {ReporterOnStartOptions} from 'types/Reporters';
+import {TestResult, Config} from '@jest/types';
 
 import chalk from 'chalk';
 import stringLength from 'string-length';
+import {ReporterOnStartOptions} from './types';
 import {
   getSummary,
   trimAndFormatPath,
@@ -29,13 +26,16 @@ const RUNNING = chalk.reset.inverse.yellow.bold(RUNNING_TEXT) + ' ';
  * shifting the whole list.
  */
 class CurrentTestList {
-  _array: Array<{testPath: Path, config: ProjectConfig} | null>;
+  private _array: Array<{
+    testPath: Config.Path;
+    config: Config.ProjectConfig;
+  } | null>;
 
   constructor() {
     this._array = [];
   }
 
-  add(testPath, config) {
+  add(testPath: Config.Path, config: Config.ProjectConfig) {
     const index = this._array.indexOf(null);
     const record = {config, testPath};
     if (index !== -1) {
@@ -45,9 +45,9 @@ class CurrentTestList {
     }
   }
 
-  delete(testPath) {
+  delete(testPath: Config.Path) {
     const record = this._array.find(
-      record => record && record.testPath === testPath,
+      record => record !== null && record.testPath === testPath,
     );
     this._array[this._array.indexOf(record || null)] = null;
   }
@@ -63,17 +63,15 @@ class CurrentTestList {
  * from the terminal.
  */
 export default class Status {
-  _cache: ?{content: string, clear: string};
-  _callback: () => void;
-  _currentTests: CurrentTestList;
-  _done: boolean;
-  _emitScheduled: boolean;
-  _estimatedTime: number;
-  _height: number;
-  _interval: IntervalID;
-  _aggregatedResults: AggregatedResult;
-  _lastUpdated: number;
-  _showStatus: boolean;
+  private _cache: {content: string; clear: string} | null;
+  private _callback?: () => void;
+  private _currentTests: CurrentTestList;
+  private _done: boolean;
+  private _emitScheduled: boolean;
+  private _estimatedTime: number;
+  private _interval?: NodeJS.Timeout;
+  private _aggregatedResults?: TestResult.AggregatedResult;
+  private _showStatus: boolean;
 
   constructor() {
     this._cache = null;
@@ -81,7 +79,6 @@ export default class Status {
     this._done = false;
     this._emitScheduled = false;
     this._estimatedTime = 0;
-    this._height = 0;
     this._showStatus = false;
   }
 
@@ -90,7 +87,7 @@ export default class Status {
   }
 
   runStarted(
-    aggregatedResults: AggregatedResult,
+    aggregatedResults: TestResult.AggregatedResult,
     options: ReporterOnStartOptions,
   ) {
     this._estimatedTime = (options && options.estimatedTime) || 0;
@@ -102,11 +99,11 @@ export default class Status {
 
   runFinished() {
     this._done = true;
-    clearInterval(this._interval);
+    if (this._interval) clearInterval(this._interval);
     this._emit();
   }
 
-  testStarted(testPath: Path, config: ProjectConfig) {
+  testStarted(testPath: Config.Path, config: Config.ProjectConfig) {
     this._currentTests.add(testPath, config);
     if (!this._showStatus) {
       this._emit();
@@ -116,9 +113,9 @@ export default class Status {
   }
 
   testFinished(
-    config: ProjectConfig,
-    testResult: TestResult,
-    aggregatedResults: AggregatedResult,
+    _config: Config.ProjectConfig,
+    testResult: TestResult.TestResult,
+    aggregatedResults: TestResult.AggregatedResult,
   ) {
     const {testFilePath} = testResult;
     this._aggregatedResults = aggregatedResults;
@@ -135,8 +132,7 @@ export default class Status {
       return {clear: '', content: ''};
     }
 
-    // $FlowFixMe
-    const width: number = process.stdout.columns;
+    const width: number = process.stdout.columns!;
     let content = '\n';
     this._currentTests.get().forEach(record => {
       if (record) {
@@ -178,13 +174,12 @@ export default class Status {
     return (this._cache = {clear, content});
   }
 
-  _emit() {
+  private _emit() {
     this._cache = null;
-    this._lastUpdated = Date.now();
-    this._callback();
+    if (this._callback) this._callback();
   }
 
-  _debouncedEmit() {
+  private _debouncedEmit() {
     if (!this._emitScheduled) {
       // Perf optimization to avoid two separate renders When
       // one test finishes and another test starts executing.
@@ -196,7 +191,7 @@ export default class Status {
     }
   }
 
-  _tick() {
+  private _tick() {
     this._debouncedEmit();
   }
 }
diff --git a/packages/jest-reporters/src/__tests__/generateEmptyCoverage.test.js b/packages/jest-reporters/src/__tests__/generateEmptyCoverage.test.js
index 00ae3f7a7ad8..678913cab672 100644
--- a/packages/jest-reporters/src/__tests__/generateEmptyCoverage.test.js
+++ b/packages/jest-reporters/src/__tests__/generateEmptyCoverage.test.js
@@ -3,8 +3,6 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
- * @flow
  */
 
 import istanbulCoverage from 'istanbul-lib-coverage';
@@ -13,7 +11,6 @@ import generateEmptyCoverage from '../generateEmptyCoverage';
 
 import path from 'path';
 import os from 'os';
-//$FlowFixMe: Converted to TS
 import {makeGlobalConfig, makeProjectConfig} from '../../../../TestUtils';
 
 jest.mock('@jest/transform', () => ({
@@ -64,6 +61,5 @@ it('generates an empty coverage object for a file without running it', () => {
     coverage = sourceMapStore.transformCoverage(coverageMap).map;
   }
 
-  // $FlowFixMe: IDK...
   expect(coverage.data).toMatchSnapshot({path: expect.any(String)});
 });
diff --git a/packages/jest-reporters/src/__tests__/get_snapshot_status.test.js b/packages/jest-reporters/src/__tests__/get_snapshot_status.test.js
index 6d722e2a7d9b..dbbaee15773b 100644
--- a/packages/jest-reporters/src/__tests__/get_snapshot_status.test.js
+++ b/packages/jest-reporters/src/__tests__/get_snapshot_status.test.js
@@ -3,7 +3,6 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
  */
 
 'use strict';
diff --git a/packages/jest-reporters/src/__tests__/notify_reporter.test.js b/packages/jest-reporters/src/__tests__/notify_reporter.test.js
index 274a2ca5d21c..9460c82ef1b7 100644
--- a/packages/jest-reporters/src/__tests__/notify_reporter.test.js
+++ b/packages/jest-reporters/src/__tests__/notify_reporter.test.js
@@ -3,7 +3,6 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
  */
 
 import type {TestSchedulerContext} from 'types/TestScheduler';
diff --git a/packages/jest-reporters/src/__tests__/utils.test.js b/packages/jest-reporters/src/__tests__/utils.test.js
index 3f45dc600d19..d842b3e5a600 100644
--- a/packages/jest-reporters/src/__tests__/utils.test.js
+++ b/packages/jest-reporters/src/__tests__/utils.test.js
@@ -3,7 +3,6 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
  */
 
 import path from 'path';
diff --git a/packages/jest-reporters/src/__tests__/verbose_reporter.test.js b/packages/jest-reporters/src/__tests__/verbose_reporter.test.js
index 206ce42ffc41..a13f6bd614bb 100644
--- a/packages/jest-reporters/src/__tests__/verbose_reporter.test.js
+++ b/packages/jest-reporters/src/__tests__/verbose_reporter.test.js
@@ -3,7 +3,6 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
  */
 
 'use strict';
diff --git a/packages/jest-reporters/src/base_reporter.js b/packages/jest-reporters/src/base_reporter.ts
similarity index 50%
rename from packages/jest-reporters/src/base_reporter.js
rename to packages/jest-reporters/src/base_reporter.ts
index 9cd86e89fb6a..36c7c57670b9 100644
--- a/packages/jest-reporters/src/base_reporter.js
+++ b/packages/jest-reporters/src/base_reporter.ts
@@ -3,46 +3,48 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
- * @flow
  */
 
-import type {AggregatedResult, TestResult} from 'types/TestResult';
-import type {Context} from 'types/Context';
-import type {Test} from 'types/TestRunner';
-import type {ReporterOnStartOptions} from 'types/Reporters';
-
+import {TestResult} from '@jest/types';
 import {preRunMessage} from 'jest-util';
+import {ReporterOnStartOptions, Context, Test, Reporter} from './types';
 
 const {remove: preRunMessageRemove} = preRunMessage;
 
-export default class BaseReporter {
-  _error: ?Error;
+export default class BaseReporter implements Reporter {
+  private _error?: Error;
 
   log(message: string) {
     process.stderr.write(message + '\n');
   }
 
-  onRunStart(results: AggregatedResult, options: ReporterOnStartOptions) {
+  onRunStart(
+    _results: TestResult.AggregatedResult,
+    _options: ReporterOnStartOptions,
+  ) {
     preRunMessageRemove(process.stderr);
   }
 
-  onTestResult(test: Test, testResult: TestResult, results: AggregatedResult) {}
+  onTestResult(
+    _test: Test,
+    _testResult: TestResult.TestResult,
+    _results: TestResult.AggregatedResult,
+  ) {}
 
-  onTestStart(test: Test) {}
+  onTestStart(_test: Test) {}
 
   onRunComplete(
-    contexts: Set<Context>,
-    aggregatedResults: AggregatedResult,
-  ): ?Promise<void> {}
+    _contexts: Set<Context>,
+    _aggregatedResults: TestResult.AggregatedResult,
+  ): Promise<void> | void {}
 
-  _setError(error: Error) {
+  protected _setError(error: Error) {
     this._error = error;
   }
 
   // Return an error that occurred during reporting. This error will
   // define whether the test run was successful or failed.
-  getLastError(): ?Error {
+  getLastError() {
     return this._error;
   }
 }
diff --git a/packages/jest-reporters/src/coverage_reporter.js b/packages/jest-reporters/src/coverage_reporter.ts
similarity index 64%
rename from packages/jest-reporters/src/coverage_reporter.js
rename to packages/jest-reporters/src/coverage_reporter.ts
index d8466110f720..c3f2004858a0 100644
--- a/packages/jest-reporters/src/coverage_reporter.js
+++ b/packages/jest-reporters/src/coverage_reporter.ts
@@ -3,49 +3,44 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
- * @flow
  */
 
-import type {
-  AggregatedResult,
-  CoverageMap,
-  FileCoverage,
-  CoverageSummary,
-  TestResult,
-} from 'types/TestResult';
-import typeof {worker} from './coverage_worker';
+// TODO: Remove this
+/// <reference path="./istanbul-lib-coverage.d.ts" />
+/// <reference path="./istanbul-api.d.ts" />
 
-import type {GlobalConfig, Path} from 'types/Config';
-import type {Context} from 'types/Context';
-import type {Test} from 'types/TestRunner';
+import path from 'path';
+import {TestResult, Config} from '@jest/types';
 
 import {clearLine, isInteractive} from 'jest-util';
 import {createReporter} from 'istanbul-api';
 import chalk from 'chalk';
-import istanbulCoverage from 'istanbul-lib-coverage';
-import libSourceMaps from 'istanbul-lib-source-maps';
+import istanbulCoverage, {
+  CoverageMap,
+  FileCoverage,
+  CoverageSummary,
+  CoverageSummaryData,
+} from 'istanbul-lib-coverage';
+import libSourceMaps, {MapStore} from 'istanbul-lib-source-maps';
 import Worker from 'jest-worker';
-import BaseReporter from './base_reporter';
-import path from 'path';
 import glob from 'glob';
+import {RawSourceMap} from 'source-map';
+import BaseReporter from './base_reporter';
+import {Context, Test, CoverageWorker, CoverageReporterOptions} from './types';
 
 const FAIL_COLOR = chalk.bold.red;
 const RUNNING_TEST_COLOR = chalk.bold.dim;
 
-type CoverageWorker = {worker: worker};
-
-export type CoverageReporterOptions = {
-  changedFiles?: Set<Path>,
-};
-
 export default class CoverageReporter extends BaseReporter {
-  _coverageMap: CoverageMap;
-  _globalConfig: GlobalConfig;
-  _sourceMapStore: any;
-  _options: CoverageReporterOptions;
-
-  constructor(globalConfig: GlobalConfig, options?: CoverageReporterOptions) {
+  private _coverageMap: CoverageMap;
+  private _globalConfig: Config.GlobalConfig;
+  private _sourceMapStore: MapStore;
+  private _options: CoverageReporterOptions;
+
+  constructor(
+    globalConfig: Config.GlobalConfig,
+    options?: CoverageReporterOptions,
+  ) {
     super();
     this._coverageMap = istanbulCoverage.createCoverageMap({});
     this._globalConfig = globalConfig;
@@ -54,9 +49,9 @@ export default class CoverageReporter extends BaseReporter {
   }
 
   onTestResult(
-    test: Test,
-    testResult: TestResult,
-    aggregatedResults: AggregatedResult,
+    _test: Test,
+    testResult: TestResult.TestResult,
+    _aggregatedResults: TestResult.AggregatedResult,
   ) {
     if (testResult.coverage) {
       this._coverageMap.merge(testResult.coverage);
@@ -64,12 +59,12 @@ export default class CoverageReporter extends BaseReporter {
       delete testResult.coverage;
 
       Object.keys(testResult.sourceMaps).forEach(sourcePath => {
-        let inputSourceMap: ?Object;
+        let inputSourceMap: RawSourceMap | undefined;
         try {
           const coverage: FileCoverage = this._coverageMap.fileCoverageFor(
             sourcePath,
           );
-          ({inputSourceMap} = coverage.toJSON());
+          ({inputSourceMap} = coverage.toJSON() as any);
         } finally {
           if (inputSourceMap) {
             this._sourceMapStore.registerMap(sourcePath, inputSourceMap);
@@ -86,7 +81,7 @@ export default class CoverageReporter extends BaseReporter {
 
   async onRunComplete(
     contexts: Set<Context>,
-    aggregatedResults: AggregatedResult,
+    aggregatedResults: TestResult.AggregatedResult,
   ) {
     await this._addUntestedFiles(this._globalConfig, contexts);
     const {map, sourceFinder} = this._sourceMapStore.transformCoverage(
@@ -121,11 +116,11 @@ export default class CoverageReporter extends BaseReporter {
     this._checkThreshold(this._globalConfig, map);
   }
 
-  async _addUntestedFiles(
-    globalConfig: GlobalConfig,
+  private async _addUntestedFiles(
+    globalConfig: Config.GlobalConfig,
     contexts: Set<Context>,
   ): Promise<void> {
-    const files = [];
+    const files: Array<{config: Config.ProjectConfig; path: string}> = [];
 
     contexts.forEach(context => {
       const config = context.config;
@@ -154,7 +149,7 @@ export default class CoverageReporter extends BaseReporter {
       );
     }
 
-    let worker: CoverageWorker;
+    let worker: CoverageWorker | Worker;
 
     if (this._globalConfig.maxWorkers <= 1) {
       worker = require('./coverage_worker');
@@ -170,7 +165,7 @@ export default class CoverageReporter extends BaseReporter {
       const filename = fileObj.path;
       const config = fileObj.config;
 
-      if (!this._coverageMap.data[filename]) {
+      if (!this._coverageMap.data[filename] && 'worker' in worker) {
         try {
           const result = await worker.worker({
             config,
@@ -210,38 +205,41 @@ export default class CoverageReporter extends BaseReporter {
       clearLine(process.stderr);
     }
 
-    if (worker && typeof worker.end === 'function') {
+    if (worker && 'end' in worker && typeof worker.end === 'function') {
       worker.end();
     }
   }
 
-  _checkThreshold(globalConfig: GlobalConfig, map: CoverageMap) {
+  private _checkThreshold(globalConfig: Config.GlobalConfig, map: CoverageMap) {
     if (globalConfig.coverageThreshold) {
-      function check(name, thresholds, actuals) {
-        return ['statements', 'branches', 'lines', 'functions'].reduce(
-          (errors, key) => {
-            const actual = actuals[key].pct;
-            const actualUncovered = actuals[key].total - actuals[key].covered;
-            const threshold = thresholds[key];
-
-            if (threshold != null) {
-              if (threshold < 0) {
-                if (threshold * -1 < actualUncovered) {
-                  errors.push(
-                    `Jest: Uncovered count for ${key} (${actualUncovered})` +
-                      `exceeds ${name} threshold (${-1 * threshold})`,
-                  );
-                }
-              } else if (actual < threshold) {
+      function check(
+        name: string,
+        thresholds: {[index: string]: number},
+        actuals: CoverageSummaryData,
+      ) {
+        return (['statements', 'branches', 'lines', 'functions'] as Array<
+          keyof CoverageSummaryData
+        >).reduce<Array<string>>((errors, key) => {
+          const actual = actuals[key].pct;
+          const actualUncovered = actuals[key].total - actuals[key].covered;
+          const threshold = thresholds[key];
+
+          if (threshold != null) {
+            if (threshold < 0) {
+              if (threshold * -1 < actualUncovered) {
                 errors.push(
-                  `Jest: "${name}" coverage threshold for ${key} (${threshold}%) not met: ${actual}%`,
+                  `Jest: Uncovered count for ${key} (${actualUncovered})` +
+                    `exceeds ${name} threshold (${-1 * threshold})`,
                 );
               }
+            } else if (actual < threshold) {
+              errors.push(
+                `Jest: "${name}" coverage threshold for ${key} (${threshold}%) not met: ${actual}%`,
+              );
             }
-            return errors;
-          },
-          [],
-        );
+          }
+          return errors;
+        }, []);
       }
 
       const THRESHOLD_GROUP_TYPES = {
@@ -251,73 +249,71 @@ export default class CoverageReporter extends BaseReporter {
       };
       const coveredFiles = map.files();
       const thresholdGroups = Object.keys(globalConfig.coverageThreshold);
-      const groupTypeByThresholdGroup = {};
-      const filesByGlob = {};
-
-      const coveredFilesSortedIntoThresholdGroup = coveredFiles.reduce(
-        (files, file) => {
-          const pathOrGlobMatches = thresholdGroups.reduce(
-            (agg, thresholdGroup) => {
-              const absoluteThresholdGroup = path.resolve(thresholdGroup);
-
-              // The threshold group might be a path:
-
-              if (file.indexOf(absoluteThresholdGroup) === 0) {
-                groupTypeByThresholdGroup[thresholdGroup] =
-                  THRESHOLD_GROUP_TYPES.PATH;
-                return agg.concat([[file, thresholdGroup]]);
-              }
+      const groupTypeByThresholdGroup: {[index: string]: string} = {};
+      const filesByGlob: {[index: string]: Array<string>} = {};
+
+      const coveredFilesSortedIntoThresholdGroup = coveredFiles.reduce<
+        Array<[string, string | undefined]>
+      >((files, file) => {
+        const pathOrGlobMatches = thresholdGroups.reduce<
+          Array<[string, string]>
+        >((agg, thresholdGroup) => {
+          const absoluteThresholdGroup = path.resolve(thresholdGroup);
+
+          // The threshold group might be a path:
+
+          if (file.indexOf(absoluteThresholdGroup) === 0) {
+            groupTypeByThresholdGroup[thresholdGroup] =
+              THRESHOLD_GROUP_TYPES.PATH;
+            return agg.concat([[file, thresholdGroup]]);
+          }
 
-              // If the threshold group is not a path it might be a glob:
+          // If the threshold group is not a path it might be a glob:
 
-              // Note: glob.sync is slow. By memoizing the files matching each glob
-              // (rather than recalculating it for each covered file) we save a tonne
-              // of execution time.
-              if (filesByGlob[absoluteThresholdGroup] === undefined) {
-                filesByGlob[absoluteThresholdGroup] = glob
-                  .sync(absoluteThresholdGroup)
-                  .map(filePath => path.resolve(filePath));
-              }
+          // Note: glob.sync is slow. By memoizing the files matching each glob
+          // (rather than recalculating it for each covered file) we save a tonne
+          // of execution time.
+          if (filesByGlob[absoluteThresholdGroup] === undefined) {
+            filesByGlob[absoluteThresholdGroup] = glob
+              .sync(absoluteThresholdGroup)
+              .map(filePath => path.resolve(filePath));
+          }
 
-              if (filesByGlob[absoluteThresholdGroup].indexOf(file) > -1) {
-                groupTypeByThresholdGroup[thresholdGroup] =
-                  THRESHOLD_GROUP_TYPES.GLOB;
-                return agg.concat([[file, thresholdGroup]]);
-              }
+          if (filesByGlob[absoluteThresholdGroup].indexOf(file) > -1) {
+            groupTypeByThresholdGroup[thresholdGroup] =
+              THRESHOLD_GROUP_TYPES.GLOB;
+            return agg.concat([[file, thresholdGroup]]);
+          }
 
-              return agg;
-            },
-            [],
-          );
+          return agg;
+        }, []);
 
-          if (pathOrGlobMatches.length > 0) {
-            return files.concat(pathOrGlobMatches);
-          }
+        if (pathOrGlobMatches.length > 0) {
+          return files.concat(pathOrGlobMatches);
+        }
 
-          // Neither a glob or a path? Toss it in global if there's a global threshold:
-          if (thresholdGroups.indexOf(THRESHOLD_GROUP_TYPES.GLOBAL) > -1) {
-            groupTypeByThresholdGroup[THRESHOLD_GROUP_TYPES.GLOBAL] =
-              THRESHOLD_GROUP_TYPES.GLOBAL;
-            return files.concat([[file, THRESHOLD_GROUP_TYPES.GLOBAL]]);
-          }
+        // Neither a glob or a path? Toss it in global if there's a global threshold:
+        if (thresholdGroups.indexOf(THRESHOLD_GROUP_TYPES.GLOBAL) > -1) {
+          groupTypeByThresholdGroup[THRESHOLD_GROUP_TYPES.GLOBAL] =
+            THRESHOLD_GROUP_TYPES.GLOBAL;
+          return files.concat([[file, THRESHOLD_GROUP_TYPES.GLOBAL]]);
+        }
 
-          // A covered file that doesn't have a threshold:
-          return files.concat([[file, undefined]]);
-        },
-        [],
-      );
+        // A covered file that doesn't have a threshold:
+        return files.concat([[file, undefined]]);
+      }, []);
 
-      const getFilesInThresholdGroup = thresholdGroup =>
+      const getFilesInThresholdGroup = (thresholdGroup: string) =>
         coveredFilesSortedIntoThresholdGroup
           .filter(fileAndGroup => fileAndGroup[1] === thresholdGroup)
           .map(fileAndGroup => fileAndGroup[0]);
 
-      function combineCoverage(filePaths) {
+      function combineCoverage(filePaths: Array<string>) {
         return filePaths
           .map(filePath => map.fileCoverageFor(filePath))
           .reduce(
             (
-              combinedCoverage: ?CoverageSummary,
+              combinedCoverage: CoverageSummary | null | undefined,
               nextFileCoverage: FileCoverage,
             ) => {
               if (combinedCoverage === undefined || combinedCoverage === null) {
@@ -329,7 +325,7 @@ export default class CoverageReporter extends BaseReporter {
           );
       }
 
-      let errors = [];
+      let errors: Array<string> = [];
 
       thresholdGroups.forEach(thresholdGroup => {
         switch (groupTypeByThresholdGroup[thresholdGroup]) {
diff --git a/packages/jest-reporters/src/coverage_worker.js b/packages/jest-reporters/src/coverage_worker.ts
similarity index 62%
rename from packages/jest-reporters/src/coverage_worker.js
rename to packages/jest-reporters/src/coverage_worker.ts
index 13c41e4dceea..6461a7973fde 100644
--- a/packages/jest-reporters/src/coverage_worker.js
+++ b/packages/jest-reporters/src/coverage_worker.ts
@@ -3,27 +3,25 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
- * @flow
  */
 
-import type {GlobalConfig, ProjectConfig, Path} from 'types/Config';
-import type {CoverageReporterOptions} from './coverage_reporter';
-
-import exit from 'exit';
 import fs from 'fs';
+import {Config} from '@jest/types';
+import exit from 'exit';
+import {CoverageReporterOptions} from './types';
+
 import generateEmptyCoverage, {
-  type CoverageWorkerResult,
+  CoverageWorkerResult,
 } from './generateEmptyCoverage';
 
-export type CoverageWorkerData = {|
-  globalConfig: GlobalConfig,
-  config: ProjectConfig,
-  path: Path,
-  options?: CoverageReporterOptions,
-|};
+export type CoverageWorkerData = {
+  globalConfig: Config.GlobalConfig;
+  config: Config.ProjectConfig;
+  path: Config.Path;
+  options?: CoverageReporterOptions;
+};
 
-export type {CoverageWorkerResult};
+export {CoverageWorkerResult};
 
 // Make sure uncaught errors are logged before we exit.
 process.on('uncaughtException', err => {
@@ -36,7 +34,7 @@ export function worker({
   globalConfig,
   path,
   options,
-}: CoverageWorkerData): ?CoverageWorkerResult {
+}: CoverageWorkerData): CoverageWorkerResult | null {
   return generateEmptyCoverage(
     fs.readFileSync(path, 'utf8'),
     path,
diff --git a/packages/jest-reporters/src/default_reporter.js b/packages/jest-reporters/src/default_reporter.ts
similarity index 79%
rename from packages/jest-reporters/src/default_reporter.js
rename to packages/jest-reporters/src/default_reporter.ts
index a842f663997a..686207e1d3ae 100644
--- a/packages/jest-reporters/src/default_reporter.js
+++ b/packages/jest-reporters/src/default_reporter.ts
@@ -3,19 +3,13 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
- * @flow
  */
 
-/* global stream$Writable, tty$WriteStream */
-
-import type {AggregatedResult, TestResult} from 'types/TestResult';
-import type {GlobalConfig, Path, ProjectConfig} from 'types/Config';
-import type {Test} from 'types/TestRunner';
-import type {ReporterOnStartOptions} from 'types/Reporters';
+import {TestResult, Config} from '@jest/types';
 
 import {clearLine, getConsoleOutput, isInteractive} from 'jest-util';
 import chalk from 'chalk';
+import {Test, ReporterOnStartOptions} from './types';
 import BaseReporter from './base_reporter';
 import Status from './Status';
 import getResultHeader from './get_result_header';
@@ -27,14 +21,14 @@ type FlushBufferedOutput = () => void;
 const TITLE_BULLET = chalk.bold('\u25cf ');
 
 export default class DefaultReporter extends BaseReporter {
-  _clear: string; // ANSI clear sequence for the last printed status
-  _err: write;
-  _globalConfig: GlobalConfig;
-  _out: write;
-  _status: Status;
-  _bufferedOutput: Set<FlushBufferedOutput>;
-
-  constructor(globalConfig: GlobalConfig) {
+  private _clear: string; // ANSI clear sequence for the last printed status
+  private _err: write;
+  protected _globalConfig: Config.GlobalConfig;
+  private _out: write;
+  private _status: Status;
+  private _bufferedOutput: Set<FlushBufferedOutput>;
+
+  constructor(globalConfig: Config.GlobalConfig) {
     super();
     this._globalConfig = globalConfig;
     this._clear = '';
@@ -50,11 +44,11 @@ export default class DefaultReporter extends BaseReporter {
     });
   }
 
-  _wrapStdio(stream: stream$Writable | tty$WriteStream) {
+  private _wrapStdio(stream: NodeJS.WritableStream | NodeJS.WriteStream) {
     const originalWrite = stream.write;
 
-    let buffer = [];
-    let timeout = null;
+    let buffer: Array<string> = [];
+    let timeout: NodeJS.Timeout | null = null;
 
     const flushBufferedOutput = () => {
       const string = buffer.join('');
@@ -88,8 +82,7 @@ export default class DefaultReporter extends BaseReporter {
       }
     };
 
-    // $FlowFixMe
-    stream.write = chunk => {
+    stream.write = (chunk: string) => {
       buffer.push(chunk);
       debouncedFlush();
       return true;
@@ -103,7 +96,7 @@ export default class DefaultReporter extends BaseReporter {
     }
   }
 
-  _clearStatus() {
+  private _clearStatus() {
     if (isInteractive) {
       if (this._globalConfig.useStderr) {
         this._err(this._clear);
@@ -113,7 +106,7 @@ export default class DefaultReporter extends BaseReporter {
     }
   }
 
-  _printStatus() {
+  private _printStatus() {
     const {content, clear} = this._status.get();
     this._clear = clear;
     if (isInteractive) {
@@ -126,7 +119,7 @@ export default class DefaultReporter extends BaseReporter {
   }
 
   onRunStart(
-    aggregatedResults: AggregatedResult,
+    aggregatedResults: TestResult.AggregatedResult,
     options: ReporterOnStartOptions,
   ) {
     this._status.runStarted(aggregatedResults, options);
@@ -139,17 +132,15 @@ export default class DefaultReporter extends BaseReporter {
   onRunComplete() {
     this.forceFlushBufferedOutput();
     this._status.runFinished();
-    // $FlowFixMe
     process.stdout.write = this._out;
-    // $FlowFixMe
     process.stderr.write = this._err;
     clearLine(process.stderr);
   }
 
   onTestResult(
     test: Test,
-    testResult: TestResult,
-    aggregatedResults: AggregatedResult,
+    testResult: TestResult.TestResult,
+    aggregatedResults: TestResult.AggregatedResult,
   ) {
     this.testFinished(test.context.config, testResult, aggregatedResults);
     if (!testResult.skipped) {
@@ -168,17 +159,17 @@ export default class DefaultReporter extends BaseReporter {
   }
 
   testFinished(
-    config: ProjectConfig,
-    testResult: TestResult,
-    aggregatedResults: AggregatedResult,
+    config: Config.ProjectConfig,
+    testResult: TestResult.TestResult,
+    aggregatedResults: TestResult.AggregatedResult,
   ) {
     this._status.testFinished(config, testResult, aggregatedResults);
   }
 
   printTestFileHeader(
-    testPath: Path,
-    config: ProjectConfig,
-    result: TestResult,
+    _testPath: Config.Path,
+    config: Config.ProjectConfig,
+    result: TestResult.TestResult,
   ) {
     this.log(getResultHeader(result, this._globalConfig, config));
     const consoleBuffer = result.console;
@@ -197,9 +188,9 @@ export default class DefaultReporter extends BaseReporter {
   }
 
   printTestFileFailureMessage(
-    testPath: Path,
-    config: ProjectConfig,
-    result: TestResult,
+    _testPath: Config.Path,
+    _config: Config.ProjectConfig,
+    result: TestResult.TestResult,
   ) {
     if (result.failureMessage) {
       this.log(result.failureMessage);
diff --git a/packages/jest-reporters/src/generateEmptyCoverage.js b/packages/jest-reporters/src/generateEmptyCoverage.ts
similarity index 74%
rename from packages/jest-reporters/src/generateEmptyCoverage.js
rename to packages/jest-reporters/src/generateEmptyCoverage.ts
index 493d251646d6..6ea3567566d9 100644
--- a/packages/jest-reporters/src/generateEmptyCoverage.js
+++ b/packages/jest-reporters/src/generateEmptyCoverage.ts
@@ -3,30 +3,30 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
- * @flow
  */
 
-import type {GlobalConfig, ProjectConfig, Path} from 'types/Config';
+// TODO: Remove this
+/// <reference path="./istanbul-lib-coverage.d.ts" />
 
+import {Config} from '@jest/types';
 import {readInitialCoverage} from 'istanbul-lib-instrument';
 import {classes} from 'istanbul-lib-coverage';
 import {shouldInstrument, ScriptTransformer} from '@jest/transform';
 
-export type CoverageWorkerResult = {|
-  coverage: any,
-  sourceMapPath: ?string,
-|};
+const FileCoverage = classes.FileCoverage;
 
-const {FileCoverage} = classes;
+export type CoverageWorkerResult = {
+  coverage: any;
+  sourceMapPath?: string | null;
+};
 
 export default function(
   source: string,
-  filename: Path,
-  globalConfig: GlobalConfig,
-  config: ProjectConfig,
-  changedFiles: ?Set<Path>,
-): ?CoverageWorkerResult {
+  filename: Config.Path,
+  globalConfig: Config.GlobalConfig,
+  config: Config.ProjectConfig,
+  changedFiles?: Set<Config.Path>,
+): CoverageWorkerResult | null {
   const coverageOptions = {
     changedFiles,
     collectCoverage: globalConfig.collectCoverage,
diff --git a/packages/jest-reporters/src/get_result_header.js b/packages/jest-reporters/src/get_result_header.ts
similarity index 85%
rename from packages/jest-reporters/src/get_result_header.js
rename to packages/jest-reporters/src/get_result_header.ts
index ada0082ce073..43c8b2301d94 100644
--- a/packages/jest-reporters/src/get_result_header.js
+++ b/packages/jest-reporters/src/get_result_header.ts
@@ -3,12 +3,9 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
- * @flow
  */
 
-import type {GlobalConfig, ProjectConfig} from 'types/Config';
-import type {TestResult} from 'types/TestResult';
+import {Config, TestResult} from '@jest/types';
 
 import chalk from 'chalk';
 import {formatTestPath, printDisplayName} from './utils';
@@ -28,9 +25,9 @@ const PASS = chalk.supportsColor
   : PASS_TEXT;
 
 export default (
-  result: TestResult,
-  globalConfig: GlobalConfig,
-  projectConfig?: ProjectConfig,
+  result: TestResult.TestResult,
+  globalConfig: Config.GlobalConfig,
+  projectConfig?: Config.ProjectConfig,
 ) => {
   const testPath = result.testFilePath;
   const status =
@@ -46,7 +43,7 @@ export default (
   }
 
   if (result.memoryUsage) {
-    const toMB = bytes => Math.floor(bytes / 1024 / 1024);
+    const toMB = (bytes: number) => Math.floor(bytes / 1024 / 1024);
     testDetail.push(`${toMB(result.memoryUsage)} MB heap size`);
   }
 
diff --git a/packages/jest-reporters/src/get_snapshot_status.js b/packages/jest-reporters/src/get_snapshot_status.ts
similarity index 93%
rename from packages/jest-reporters/src/get_snapshot_status.js
rename to packages/jest-reporters/src/get_snapshot_status.ts
index 8406fa3fa3a2..91c4e692eb90 100644
--- a/packages/jest-reporters/src/get_snapshot_status.js
+++ b/packages/jest-reporters/src/get_snapshot_status.ts
@@ -3,11 +3,9 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
- * @flow
  */
 
-import type {TestResult} from 'types/TestResult';
+import {TestResult} from '@jest/types';
 
 import chalk from 'chalk';
 
@@ -21,7 +19,7 @@ const SNAPSHOT_UPDATED = chalk.bold.green;
 const SNAPSHOT_OUTDATED = chalk.bold.yellow;
 
 export default (
-  snapshot: $PropertyType<TestResult, 'snapshot'>,
+  snapshot: TestResult.TestResult['snapshot'],
   afterUpdate: boolean,
 ): Array<string> => {
   const statuses = [];
diff --git a/packages/jest-reporters/src/get_snapshot_summary.js b/packages/jest-reporters/src/get_snapshot_summary.ts
similarity index 95%
rename from packages/jest-reporters/src/get_snapshot_summary.js
rename to packages/jest-reporters/src/get_snapshot_summary.ts
index 60eea8aa0cab..19027f821aca 100644
--- a/packages/jest-reporters/src/get_snapshot_summary.js
+++ b/packages/jest-reporters/src/get_snapshot_summary.ts
@@ -3,12 +3,9 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
- * @flow
  */
 
-import type {SnapshotSummary} from 'types/TestResult';
-import type {GlobalConfig} from 'types/Config';
+import {Config, TestResult} from '@jest/types';
 
 import chalk from 'chalk';
 import {pluralize} from 'jest-util';
@@ -26,8 +23,8 @@ const SNAPSHOT_SUMMARY = chalk.bold;
 const SNAPSHOT_UPDATED = chalk.bold.green;
 
 export default (
-  snapshots: SnapshotSummary,
-  globalConfig: GlobalConfig,
+  snapshots: TestResult.SnapshotSummary,
+  globalConfig: Config.GlobalConfig,
   updateCommand: string,
 ): Array<string> => {
   const summary = [];
diff --git a/packages/jest-reporters/src/index.js b/packages/jest-reporters/src/index.ts
similarity index 97%
rename from packages/jest-reporters/src/index.js
rename to packages/jest-reporters/src/index.ts
index c714b0cce89c..d706797ee0fd 100644
--- a/packages/jest-reporters/src/index.js
+++ b/packages/jest-reporters/src/index.ts
@@ -3,8 +3,6 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
- * @flow
  */
 
 export {default as BaseReporter} from './base_reporter';
diff --git a/packages/jest-reporters/src/istanbul-api.d.ts b/packages/jest-reporters/src/istanbul-api.d.ts
new file mode 100644
index 000000000000..d39fef7f7ee6
--- /dev/null
+++ b/packages/jest-reporters/src/istanbul-api.d.ts
@@ -0,0 +1,21 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+declare module 'istanbul-api' {
+  class Reporter {
+    constructor(config?: object, options?: object);
+    add(format: string): void;
+    addAll(formats: Array<string>): void;
+    write(coverageMap: object, options: object): void;
+    config: object;
+    dir: string;
+    reports: object;
+    summarizer: string;
+  }
+
+  function createReporter(config?: object, options?: object): Reporter;
+}
diff --git a/packages/jest-reporters/src/istanbul-lib-coverage.d.ts b/packages/jest-reporters/src/istanbul-lib-coverage.d.ts
new file mode 100644
index 000000000000..360455ca42b5
--- /dev/null
+++ b/packages/jest-reporters/src/istanbul-lib-coverage.d.ts
@@ -0,0 +1,128 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+declare module 'istanbul-lib-coverage' {
+  export interface CoverageSummaryData {
+    lines: Totals;
+    statements: Totals;
+    branches: Totals;
+    functions: Totals;
+  }
+
+  export class CoverageSummary {
+    constructor(data: CoverageSummary | CoverageSummaryData);
+    merge(obj: CoverageSummary): CoverageSummary;
+    toJSON(): CoverageSummaryData;
+    isEmpty(): boolean;
+    data: CoverageSummaryData;
+    lines: Totals;
+    statements: Totals;
+    branches: Totals;
+    functions: Totals;
+  }
+
+  export interface CoverageMapData {
+    [key: string]: FileCoverage;
+  }
+
+  export class CoverageMap {
+    constructor(data: CoverageMapData | CoverageMap);
+    addFileCoverage(
+      pathOrObject: string | FileCoverage | FileCoverageData,
+    ): void;
+    files(): Array<string>;
+    fileCoverageFor(filename: string): FileCoverage;
+    filter(callback: (key: string) => boolean): void;
+    getCoverageSummary(): CoverageSummary;
+    merge(data: CoverageMapData | CoverageMap): void;
+    toJSON(): CoverageMapData;
+    data: CoverageMapData;
+  }
+
+  export interface Location {
+    line: number;
+    column: number;
+  }
+
+  export interface Range {
+    start: Location;
+    end: Location;
+  }
+
+  export interface BranchMapping {
+    loc: Range;
+    type: string;
+    locations: Array<Range>;
+    line: number;
+  }
+
+  export interface FunctionMapping {
+    name: string;
+    decl: Range;
+    loc: Range;
+    line: number;
+  }
+
+  export interface FileCoverageData {
+    path: string;
+    statementMap: {[key: string]: Range};
+    fnMap: {[key: string]: FunctionMapping};
+    branchMap: {[key: string]: BranchMapping};
+    s: {[key: string]: number};
+    f: {[key: string]: number};
+    b: {[key: string]: Array<number>};
+  }
+
+  export interface Totals {
+    total: number;
+    covered: number;
+    skipped: number;
+    pct: number;
+  }
+
+  export interface Coverage {
+    covered: number;
+    total: number;
+    coverage: number;
+  }
+
+  export class FileCoverage implements FileCoverageData {
+    constructor(data: string | FileCoverage | FileCoverageData);
+    merge(other: FileCoverageData): void;
+    getBranchCoverageByLine(): {[line: number]: Coverage};
+    getLineCoverage(): {[line: number]: number};
+    getUncoveredLines(): Array<number>;
+    resetHits(): void;
+    computeBranchTotals(): Totals;
+    computeSimpleTotals(): Totals;
+    toSummary(): CoverageSummary;
+    toJSON(): object;
+
+    data: FileCoverageData;
+    path: string;
+    statementMap: {[key: string]: Range};
+    fnMap: {[key: string]: FunctionMapping};
+    branchMap: {[key: string]: BranchMapping};
+    s: {[key: string]: number};
+    f: {[key: string]: number};
+    b: {[key: string]: Array<number>};
+  }
+
+  export const classes: {
+    FileCoverage: typeof FileCoverage;
+  };
+
+  export function createCoverageMap(
+    data?: CoverageMap | CoverageMapData,
+  ): CoverageMap;
+  export function createCoverageSummary(
+    obj?: CoverageSummary | CoverageSummaryData,
+  ): CoverageSummary;
+  export function createFileCoverage(
+    pathOrObject: string | FileCoverage | FileCoverageData,
+  ): FileCoverage;
+}
diff --git a/packages/jest-reporters/src/node-notifier.d.ts b/packages/jest-reporters/src/node-notifier.d.ts
new file mode 100644
index 000000000000..27a27e1211dd
--- /dev/null
+++ b/packages/jest-reporters/src/node-notifier.d.ts
@@ -0,0 +1,255 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+/// <reference types="node" />
+
+// TODO: Replace with @types/node-notifier
+declare module 'node-notifier' {
+  import NotificationCenter = require('node-notifier/notifiers/notificationcenter');
+  import NotifySend = require('node-notifier/notifiers/notifysend');
+  import WindowsToaster = require('node-notifier/notifiers/toaster');
+  import WindowsBalloon = require('node-notifier/notifiers/balloon');
+  import Growl = require('node-notifier/notifiers/growl');
+
+  namespace nodeNotifier {
+    interface NodeNotifier extends NodeJS.EventEmitter {
+      notify(
+        notification?: NotificationCenter.Notification,
+        callback?: NotificationCallback,
+      ): NotificationCenter;
+      notify(
+        notification?: WindowsToaster.Notification,
+        callback?: NotificationCallback,
+      ): WindowsToaster;
+      notify(
+        notification?: WindowsBalloon.Notification,
+        callback?: NotificationCallback,
+      ): WindowsBalloon;
+      notify(
+        notification?: NotifySend.Notification,
+        callback?: NotificationCallback,
+      ): NotifySend;
+      notify(
+        notification?: Growl.Notification,
+        callback?: NotificationCallback,
+      ): Growl;
+      notify(
+        notification?: Notification,
+        callback?: NotificationCallback,
+      ): NodeNotifier;
+      notify(
+        notification?: string,
+        callback?: NotificationCallback,
+      ): NodeNotifier;
+      NotificationCenter: typeof NotificationCenter;
+      NotifySend: typeof NotifySend;
+      WindowsToaster: typeof WindowsToaster;
+      WindowsBalloon: typeof WindowsBalloon;
+      Growl: typeof Growl;
+    }
+
+    interface Notification {
+      title?: string;
+      message?: string;
+      /** Absolute path (not balloons) */
+      icon?: string;
+      /** Wait with callback until user action is taken on notification */
+      wait?: boolean;
+    }
+
+    interface NotificationMetadata {
+      activationType?: string;
+      activationAt?: string;
+      deliveredAt?: string;
+      activationValue?: string;
+      activationValueIndex?: string;
+    }
+
+    interface NotificationCallback {
+      (
+        err: Error | null,
+        response: string,
+        metadata?: NotificationMetadata,
+      ): void;
+    }
+
+    interface Option {
+      withFallback?: boolean;
+      customPath?: string;
+    }
+  }
+
+  const nodeNotifier: nodeNotifier.NodeNotifier;
+
+  export = nodeNotifier;
+}
+
+declare module 'node-notifier/notifiers/notificationcenter' {
+  import notifier = require('node-notifier');
+
+  class NotificationCenter {
+    constructor(option?: notifier.Option);
+    notify(
+      notification?: NotificationCenter.Notification,
+      callback?: notifier.NotificationCallback,
+    ): NotificationCenter;
+  }
+
+  namespace NotificationCenter {
+    interface Notification extends notifier.Notification {
+      /**
+       * Case Sensitive string for location of sound file, or use one of macOS' native sounds.
+       */
+      sound?: boolean | string;
+      subtitle?: string;
+      /** Attach image? (Absolute path) */
+      contentImage?: string;
+      /** URL to open on click */
+      open?: string;
+      /**
+       * The amount of seconds before the notification closes.
+       * Takes precedence over wait if both are defined.
+       */
+      timeout?: number;
+      /** Label for cancel button */
+      closeLabel?: string;
+      /** Action label or list of labels in case of dropdown. */
+      actions?: string | Array<string>;
+      /** Label to be used if there are multiple actions */
+      dropdownLabel?: string;
+      /**
+       * If notification should take input.
+       * Value passed as third argument in callback and event emitter.
+       */
+      reply?: boolean;
+    }
+  }
+
+  export = NotificationCenter;
+}
+
+declare module 'node-notifier/notifiers/notifysend' {
+  import notifier = require('node-notifier');
+
+  class NotifySend {
+    constructor(option?: notifier.Option);
+    notify(
+      notification?: NotifySend.Notification,
+      callback?: notifier.NotificationCallback,
+    ): NotifySend;
+  }
+
+  namespace NotifySend {
+    interface Notification {
+      title?: string;
+      message?: string;
+      icon?: string;
+      /** Specifies the urgency level  (low,  normal,  critical). */
+      urgency?: string;
+      /** Specifies  the  timeout  in  milliseconds at which to expire the notification */
+      time?: number;
+      /** Specifies the notification category */
+      category?: string;
+      /** Specifies basic extra data to pass. Valid types are int, double, string and byte. */
+      hint?: string;
+    }
+  }
+
+  export = NotifySend;
+}
+
+declare module 'node-notifier/notifiers/toaster' {
+  import notifier = require('node-notifier');
+
+  class WindowsToaster {
+    constructor(option?: notifier.Option);
+    notify(
+      notification?: WindowsToaster.Notification,
+      callback?: notifier.NotificationCallback,
+    ): WindowsToaster;
+  }
+
+  namespace WindowsToaster {
+    interface Notification extends notifier.Notification {
+      /**
+       * Defined by http://msdn.microsoft.com/en-us/library/windows/apps/hh761492.aspx
+       */
+      sound?: boolean | string;
+      /** ID to use for closing notification. */
+      id?: number;
+      /** App.ID and app Name. Defaults to no value, causing SnoreToast text to be visible. */
+      appID?: string;
+      /** Refer to previously created notification to close. */
+      remove?: number;
+      /**
+       * Creates a shortcut <path> in the start menu which point to the
+       * executable <application>, appID used for the notifications.
+       */
+      install?: string;
+    }
+  }
+
+  export = WindowsToaster;
+}
+
+declare module 'node-notifier/notifiers/growl' {
+  import notifier = require('node-notifier');
+
+  class Growl {
+    constructor(option?: Growl.Option);
+    notify(
+      notification?: Growl.Notification,
+      callback?: notifier.NotificationCallback,
+    ): Growl;
+  }
+
+  namespace Growl {
+    interface Option {
+      name?: string;
+      host?: string;
+      port?: number;
+    }
+
+    interface Notification extends notifier.Notification {
+      /** whether or not to sticky the notification (defaults to false) */
+      sticky?: boolean;
+      /** type of notification to use (defaults to the first registered type) */
+      label?: string;
+      /** the priority of the notification from lowest (-2) to highest (2) */
+      priority?: number;
+    }
+  }
+
+  export = Growl;
+}
+
+declare module 'node-notifier/notifiers/balloon' {
+  import notifier = require('node-notifier');
+
+  class WindowsBalloon {
+    constructor(option?: notifier.Option);
+    notify(
+      notification?: WindowsBalloon.Notification,
+      callback?: notifier.NotificationCallback,
+    ): WindowsBalloon;
+  }
+
+  namespace WindowsBalloon {
+    interface Notification {
+      title?: string;
+      message?: string;
+      /** How long to show balloons in ms */
+      time?: number;
+      /** Wait with callback until user action is taken on notification */
+      wait?: boolean;
+      /** The notification type */
+      type?: 'info' | 'warn' | 'error';
+    }
+  }
+
+  export = WindowsBalloon;
+}
diff --git a/packages/jest-reporters/src/notify_reporter.js b/packages/jest-reporters/src/notify_reporter.ts
similarity index 87%
rename from packages/jest-reporters/src/notify_reporter.js
rename to packages/jest-reporters/src/notify_reporter.ts
index 9a6c9a27f3cb..b6755b85b25c 100644
--- a/packages/jest-reporters/src/notify_reporter.js
+++ b/packages/jest-reporters/src/notify_reporter.ts
@@ -3,19 +3,17 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
- * @flow
  */
 
-import type {GlobalConfig} from 'types/Config';
-import type {AggregatedResult} from 'types/TestResult';
-import type {TestSchedulerContext} from 'types/TestScheduler';
-import type {Context} from 'types/Context';
+// TODO: Remove this
+/// <reference path="./node-notifier.d.ts" />
 
-import exit from 'exit';
 import path from 'path';
 import util from 'util';
+import exit from 'exit';
+import {Config, TestResult} from '@jest/types';
 import notifier from 'node-notifier';
+import {TestSchedulerContext, Context} from './types';
 import BaseReporter from './base_reporter';
 
 const isDarwin = process.platform === 'darwin';
@@ -23,12 +21,13 @@ const isDarwin = process.platform === 'darwin';
 const icon = path.resolve(__dirname, '../assets/jest_logo.png');
 
 export default class NotifyReporter extends BaseReporter {
-  _startRun: (globalConfig: GlobalConfig) => *;
-  _globalConfig: GlobalConfig;
-  _context: TestSchedulerContext;
+  private _startRun: (globalConfig: Config.GlobalConfig) => any;
+  private _globalConfig: Config.GlobalConfig;
+  private _context: TestSchedulerContext;
+
   constructor(
-    globalConfig: GlobalConfig,
-    startRun: (globalConfig: GlobalConfig) => *,
+    globalConfig: Config.GlobalConfig,
+    startRun: (globalConfig: Config.GlobalConfig) => any,
     context: TestSchedulerContext,
   ) {
     super();
@@ -37,7 +36,10 @@ export default class NotifyReporter extends BaseReporter {
     this._context = context;
   }
 
-  onRunComplete(contexts: Set<Context>, result: AggregatedResult): void {
+  onRunComplete(
+    contexts: Set<Context>,
+    result: TestResult.AggregatedResult,
+  ): void {
     const success =
       result.numFailedTests === 0 && result.numRuntimeErrorTestSuites === 0;
 
diff --git a/packages/jest-reporters/src/summary_reporter.js b/packages/jest-reporters/src/summary_reporter.ts
similarity index 87%
rename from packages/jest-reporters/src/summary_reporter.js
rename to packages/jest-reporters/src/summary_reporter.ts
index 863ab6e0db41..cf392376c53f 100644
--- a/packages/jest-reporters/src/summary_reporter.js
+++ b/packages/jest-reporters/src/summary_reporter.ts
@@ -3,17 +3,12 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
- * @flow
  */
 
-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 {TestResult, Config} from '@jest/types';
 import chalk from 'chalk';
 import {testPathPatternToRegExp} from 'jest-util';
+import {Context, ReporterOnStartOptions} from './types';
 import BaseReporter from './base_reporter';
 import {getSummary} from './utils';
 import getResultHeader from './get_result_header';
@@ -49,10 +44,10 @@ const NPM_EVENTS = new Set([
 ]);
 
 export default class SummaryReporter extends BaseReporter {
-  _estimatedTime: number;
-  _globalConfig: GlobalConfig;
+  private _estimatedTime: number;
+  private _globalConfig: Config.GlobalConfig;
 
-  constructor(globalConfig: GlobalConfig) {
+  constructor(globalConfig: Config.GlobalConfig) {
     super();
     this._globalConfig = globalConfig;
     this._estimatedTime = 0;
@@ -63,21 +58,24 @@ export default class SummaryReporter extends BaseReporter {
   // in Node.js 0.10 and still persists in Node.js 6.7+.
   // Let's print the test failure summary character by character which is safer
   // when hundreds of tests are failing.
-  _write(string: string) {
+  private _write(string: string) {
     for (let i = 0; i < string.length; i++) {
       process.stderr.write(string.charAt(i));
     }
   }
 
   onRunStart(
-    aggregatedResults: AggregatedResult,
+    aggregatedResults: TestResult.AggregatedResult,
     options: ReporterOnStartOptions,
   ) {
     super.onRunStart(aggregatedResults, options);
     this._estimatedTime = options.estimatedTime;
   }
 
-  onRunComplete(contexts: Set<Context>, aggregatedResults: AggregatedResult) {
+  onRunComplete(
+    contexts: Set<Context>,
+    aggregatedResults: TestResult.AggregatedResult,
+  ) {
     const {numTotalTestSuites, testResults, wasInterrupted} = aggregatedResults;
     if (numTotalTestSuites) {
       const lastResult = testResults[testResults.length - 1];
@@ -115,9 +113,9 @@ export default class SummaryReporter extends BaseReporter {
     }
   }
 
-  _printSnapshotSummary(
-    snapshots: SnapshotSummary,
-    globalConfig: GlobalConfig,
+  private _printSnapshotSummary(
+    snapshots: TestResult.SnapshotSummary,
+    globalConfig: Config.GlobalConfig,
   ) {
     if (
       snapshots.added ||
@@ -127,7 +125,7 @@ export default class SummaryReporter extends BaseReporter {
       snapshots.updated
     ) {
       let updateCommand;
-      const event = process.env.npm_lifecycle_event;
+      const event = process.env.npm_lifecycle_event || '';
       const prefix = NPM_EVENTS.has(event) ? '' : 'run ';
       const isYarn =
         typeof process.env.npm_config_user_agent === 'string' &&
@@ -160,9 +158,9 @@ export default class SummaryReporter extends BaseReporter {
     }
   }
 
-  _printSummary(
-    aggregatedResults: AggregatedResult,
-    globalConfig: GlobalConfig,
+  private _printSummary(
+    aggregatedResults: TestResult.AggregatedResult,
+    globalConfig: Config.GlobalConfig,
   ) {
     // If there were any failing tests and there was a large number of tests
     // executed, re-print the failing results at the end of execution output.
@@ -188,7 +186,10 @@ export default class SummaryReporter extends BaseReporter {
     }
   }
 
-  _getTestSummary(contexts: Set<Context>, globalConfig: GlobalConfig) {
+  private _getTestSummary(
+    contexts: Set<Context>,
+    globalConfig: Config.GlobalConfig,
+  ) {
     const getMatchingTestsInfo = () => {
       const prefix = globalConfig.findRelatedTests
         ? ' related to files matching '
diff --git a/packages/jest-reporters/src/types.ts b/packages/jest-reporters/src/types.ts
new file mode 100644
index 000000000000..cfdde6598abc
--- /dev/null
+++ b/packages/jest-reporters/src/types.ts
@@ -0,0 +1,98 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {Config, TestResult} from '@jest/types';
+import {JestEnvironment as Environment} from '@jest/environment';
+import {ModuleMap, FS as HasteFS} from 'jest-haste-map';
+import HasteResolver from 'jest-resolve';
+import Runtime from 'jest-runtime';
+import {worker} from './coverage_worker';
+
+export type ReporterOnStartOptions = {
+  estimatedTime: number;
+  showStatus: boolean;
+};
+
+export type Context = {
+  config: Config.ProjectConfig;
+  hasteFS: HasteFS;
+  moduleMap: ModuleMap;
+  resolver: HasteResolver;
+};
+
+export type Test = {
+  context: Context;
+  duration?: number;
+  path: Config.Path;
+};
+
+export type CoverageWorker = {worker: typeof worker};
+
+export type CoverageReporterOptions = {
+  changedFiles?: Set<Config.Path>;
+};
+
+export type OnTestStart = (test: Test) => Promise<void>;
+export type OnTestFailure = (
+  test: Test,
+  error: TestResult.SerializableError,
+) => Promise<any>;
+export type OnTestSuccess = (
+  test: Test,
+  result: TestResult.TestResult,
+) => Promise<any>;
+
+export interface Reporter {
+  readonly onTestResult: (
+    test: Test,
+    testResult: TestResult.TestResult,
+    aggregatedResult: TestResult.AggregatedResult,
+  ) => Promise<void> | void;
+  readonly onRunStart: (
+    results: TestResult.AggregatedResult,
+    options: ReporterOnStartOptions,
+  ) => Promise<void> | void;
+  readonly onTestStart: (test: Test) => Promise<void> | void;
+  readonly onRunComplete: (
+    contexts: Set<Context>,
+    results: TestResult.AggregatedResult,
+  ) => Promise<void> | void;
+  readonly getLastError: () => Error | void;
+}
+
+export type SummaryOptions = {
+  estimatedTime?: number;
+  roundTime?: boolean;
+  width?: number;
+};
+
+export type TestFramework = (
+  globalConfig: Config.GlobalConfig,
+  config: Config.ProjectConfig,
+  environment: Environment,
+  runtime: Runtime,
+  testPath: string,
+) => Promise<TestResult.TestResult>;
+
+export type TestRunnerOptions = {
+  serial: boolean;
+};
+
+export type TestRunnerContext = {
+  changedFiles?: Set<Config.Path>;
+};
+
+export type TestRunData = Array<{
+  context: Context;
+  matches: {allTests: number; tests: Array<Test>; total: number};
+}>;
+
+export type TestSchedulerContext = {
+  firstRun: boolean;
+  previousSuccess: boolean;
+  changedFiles?: Set<Config.Path>;
+};
diff --git a/packages/jest-reporters/src/utils.js b/packages/jest-reporters/src/utils.ts
similarity index 92%
rename from packages/jest-reporters/src/utils.js
rename to packages/jest-reporters/src/utils.ts
index f2f17e52f0a2..d078b584fbf0 100644
--- a/packages/jest-reporters/src/utils.js
+++ b/packages/jest-reporters/src/utils.ts
@@ -3,27 +3,18 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
- * @flow
  */
 
-import type {Path, ProjectConfig, GlobalConfig} from 'types/Config';
-import type {AggregatedResult} from 'types/TestResult';
-
 import path from 'path';
+import {Config, TestResult} from '@jest/types';
 import chalk from 'chalk';
 import slash from 'slash';
 import {pluralize} from 'jest-util';
-
-type SummaryOptions = {|
-  estimatedTime?: number,
-  roundTime?: boolean,
-  width?: number,
-|};
+import {SummaryOptions} from './types';
 
 const PROGRESS_BAR_WIDTH = 40;
 
-export const printDisplayName = (config: ProjectConfig) => {
+export const printDisplayName = (config: Config.ProjectConfig) => {
   const {displayName} = config;
 
   if (displayName) {
@@ -37,8 +28,8 @@ export const printDisplayName = (config: ProjectConfig) => {
 
 export const trimAndFormatPath = (
   pad: number,
-  config: ProjectConfig | GlobalConfig,
-  testPath: Path,
+  config: Config.ProjectConfig | Config.GlobalConfig,
+  testPath: Config.Path,
   columns: number,
 ): string => {
   const maxLength = columns - pad;
@@ -73,28 +64,31 @@ export const trimAndFormatPath = (
 };
 
 export const formatTestPath = (
-  config: GlobalConfig | ProjectConfig,
-  testPath: Path,
+  config: Config.GlobalConfig | Config.ProjectConfig,
+  testPath: Config.Path,
 ) => {
   const {dirname, basename} = relativePath(config, testPath);
   return slash(chalk.dim(dirname + path.sep) + chalk.bold(basename));
 };
 
 export const relativePath = (
-  config: GlobalConfig | ProjectConfig,
-  testPath: Path,
+  config: Config.GlobalConfig | Config.ProjectConfig,
+  testPath: Config.Path,
 ) => {
   // this function can be called with ProjectConfigs or GlobalConfigs. GlobalConfigs
   // do not have config.cwd, only config.rootDir. Try using config.cwd, fallback
   // to config.rootDir. (Also, some unit just use config.rootDir, which is ok)
-  testPath = path.relative(config.cwd || config.rootDir, testPath);
+  testPath = path.relative(
+    (config as Config.ProjectConfig).cwd || config.rootDir,
+    testPath,
+  );
   const dirname = path.dirname(testPath);
   const basename = path.basename(testPath);
   return {basename, dirname};
 };
 
 export const getSummary = (
-  aggregatedResults: AggregatedResult,
+  aggregatedResults: TestResult.AggregatedResult,
   options?: SummaryOptions,
 ) => {
   let runTime = (Date.now() - aggregatedResults.startTime) / 1000;
@@ -180,7 +174,7 @@ export const getSummary = (
   return [suites, tests, snapshots, time].join('\n');
 };
 
-const renderTime = (runTime, estimatedTime, width) => {
+const renderTime = (runTime: number, estimatedTime: number, width: number) => {
   // If we are more than one second over the estimated time, highlight it.
   const renderedTime =
     estimatedTime && runTime >= estimatedTime + 1
diff --git a/packages/jest-reporters/src/verbose_reporter.js b/packages/jest-reporters/src/verbose_reporter.ts
similarity index 79%
rename from packages/jest-reporters/src/verbose_reporter.js
rename to packages/jest-reporters/src/verbose_reporter.ts
index 4a1ecc646e08..74ac6794f27c 100644
--- a/packages/jest-reporters/src/verbose_reporter.js
+++ b/packages/jest-reporters/src/verbose_reporter.ts
@@ -3,41 +3,33 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- *
- * @flow
  */
 
-import type {GlobalConfig} from 'types/Config';
-import type {
-  AggregatedResult,
-  AssertionResult,
-  Suite,
-  TestResult,
-} from 'types/TestResult';
-import type {Test} from 'types/TestRunner';
+import {Config, TestResult} from '@jest/types';
 
 import chalk from 'chalk';
 import {specialChars} from 'jest-util';
+import {Test} from './types';
 import DefaultReporter from './default_reporter';
 
 const {ICONS} = specialChars;
 
 export default class VerboseReporter extends DefaultReporter {
-  _globalConfig: GlobalConfig;
+  protected _globalConfig: Config.GlobalConfig;
 
-  constructor(globalConfig: GlobalConfig) {
+  constructor(globalConfig: Config.GlobalConfig) {
     super(globalConfig);
     this._globalConfig = globalConfig;
   }
 
   static filterTestResults(
-    testResults: Array<AssertionResult>,
-  ): Array<AssertionResult> {
+    testResults: Array<TestResult.AssertionResult>,
+  ): Array<TestResult.AssertionResult> {
     return testResults.filter(({status}) => status !== 'pending');
   }
 
-  static groupTestsBySuites(testResults: Array<AssertionResult>) {
-    const root = {suites: [], tests: [], title: ''};
+  static groupTestsBySuites(testResults: Array<TestResult.AssertionResult>) {
+    const root: TestResult.Suite = {suites: [], tests: [], title: ''};
     testResults.forEach(testResult => {
       let targetSuite = root;
 
@@ -59,8 +51,8 @@ export default class VerboseReporter extends DefaultReporter {
 
   onTestResult(
     test: Test,
-    result: TestResult,
-    aggregatedResults: AggregatedResult,
+    result: TestResult.TestResult,
+    aggregatedResults: TestResult.AggregatedResult,
   ) {
     super.testFinished(test.context.config, result, aggregatedResults);
     if (!result.skipped) {
@@ -81,12 +73,12 @@ export default class VerboseReporter extends DefaultReporter {
     super.forceFlushBufferedOutput();
   }
 
-  _logTestResults(testResults: Array<AssertionResult>) {
+  private _logTestResults(testResults: Array<TestResult.AssertionResult>) {
     this._logSuite(VerboseReporter.groupTestsBySuites(testResults), 0);
     this._logLine();
   }
 
-  _logSuite(suite: Suite, indentLevel: number) {
+  private _logSuite(suite: TestResult.Suite, indentLevel: number) {
     if (suite.title) {
       this._logLine(suite.title, indentLevel);
     }
@@ -96,7 +88,7 @@ export default class VerboseReporter extends DefaultReporter {
     suite.suites.forEach(suite => this._logSuite(suite, indentLevel + 1));
   }
 
-  _getIcon(status: string) {
+  private _getIcon(status: string) {
     if (status === 'failed') {
       return chalk.red(ICONS.failed);
     } else if (status === 'pending') {
@@ -108,13 +100,16 @@ export default class VerboseReporter extends DefaultReporter {
     }
   }
 
-  _logTest(test: AssertionResult, indentLevel: number) {
+  private _logTest(test: TestResult.AssertionResult, indentLevel: number) {
     const status = this._getIcon(test.status);
     const time = test.duration ? ` (${test.duration.toFixed(0)}ms)` : '';
     this._logLine(status + ' ' + chalk.dim(test.title + time), indentLevel);
   }
 
-  _logTests(tests: Array<AssertionResult>, indentLevel: number) {
+  private _logTests(
+    tests: Array<TestResult.AssertionResult>,
+    indentLevel: number,
+  ) {
     if (this._globalConfig.expand) {
       tests.forEach(test => this._logTest(test, indentLevel));
     } else {
@@ -153,7 +148,7 @@ export default class VerboseReporter extends DefaultReporter {
     }
   }
 
-  _logSummedTests(
+  private _logSummedTests(
     prefix: string,
     icon: string,
     count: number,
@@ -163,7 +158,7 @@ export default class VerboseReporter extends DefaultReporter {
     this._logLine(`${icon} ${text}`, indentLevel);
   }
 
-  _logLine(str?: string, indentLevel?: number) {
+  private _logLine(str?: string, indentLevel?: number) {
     const indentation = '  '.repeat(indentLevel || 0);
     this.log(indentation + (str || ''));
   }
diff --git a/packages/jest-reporters/tsconfig.json b/packages/jest-reporters/tsconfig.json
new file mode 100644
index 000000000000..5f38de20815b
--- /dev/null
+++ b/packages/jest-reporters/tsconfig.json
@@ -0,0 +1,16 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "build"
+  },
+  "references": [
+    {"path": "../jest-environment"},
+    {"path": "../jest-haste-map"},
+    {"path": "../jest-resolve"},
+    {"path": "../jest-runtime"},
+    {"path": "../jest-types"},
+    {"path": "../jest-util"},
+    {"path": "../jest-worker"}
+  ]
+}
diff --git a/packages/jest-types/src/Config.ts b/packages/jest-types/src/Config.ts
index c2c70c829be9..cffb4ba74e32 100644
--- a/packages/jest-types/src/Config.ts
+++ b/packages/jest-types/src/Config.ts
@@ -223,6 +223,15 @@ type NotifyMode =
   | 'success-change'
   | 'failure-change';
 
+type CoverageThreshold = {
+  [path: string]: {
+    [key: string]: number;
+  };
+  global: {
+    [key: string]: number;
+  };
+};
+
 export type GlobalConfig = {
   bail: number;
   changedSince: string;
@@ -238,11 +247,7 @@ export type GlobalConfig = {
   coverageDirectory: string;
   coveragePathIgnorePatterns?: Array<string>;
   coverageReporters: Array<string>;
-  coverageThreshold: {
-    global: {
-      [key: string]: number;
-    };
-  };
+  coverageThreshold: CoverageThreshold;
   detectLeaks: boolean;
   detectOpenHandles: boolean;
   enabledTestsMap:
diff --git a/yarn.lock b/yarn.lock
index 2a165b6d6a2f..35dfdc279ddb 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1732,13 +1732,6 @@
   resolved "https://registry.yarnpkg.com/@types/natural-compare/-/natural-compare-1.4.0.tgz#b3c54f7edc339758d573c5dcac7808c58cf8c31e"
   integrity sha512-bNtBj6AF1F90jp54KRPOrYfilGNfPr2kpaUN7rMJjauAtfGBXzT/T/REZN6jb4qUs9FTxU37kir3Nrn5WsTUDw==
 
-"@types/node-notifier@^0.0.28":
-  version "0.0.28"
-  resolved "https://registry.yarnpkg.com/@types/node-notifier/-/node-notifier-0.0.28.tgz#86ba3d3aa8d918352cc3191d88de328b20dc93c1"
-  integrity sha1-hro9OqjZGDUswxkdiN4yiyDck8E=
-  dependencies:
-    "@types/node" "*"
-
 "@types/node@*", "@types/node@^11.9.6":
   version "11.9.6"
   resolved "https://registry.yarnpkg.com/@types/node/-/node-11.9.6.tgz#c632bbcc780a1349673a6e2e9b9dfa8c369d3c74"