Allow plugins to override other plugins

packages/jest-cli/src/__tests__/__snapshots__/watch.test.js.snap

@@ -21,6 +21,20 @@ Watch Usage
 ]
 `;
 
+exports[`Watch mode flows allows WatchPlugins to override internal plugins 1`] = `
+Array [
+  "
+Watch Usage
+ › Press a to run all tests.
+ › Press f to run only failed tests.
+ › Press t to filter by a test name regex pattern.
+ › Press q to quit watch mode.
+ › Press p to custom \\"P\\" plugin.
+ › Press Enter to trigger a test run.
+",
+]
+`;
+
 exports[`Watch mode flows shows prompts for WatchPlugins in alphabetical order 1`] = `
 Array [
   Array [

packages/jest-cli/src/__tests__/watch.test.js

@@ -317,6 +317,47 @@ describe('Watch mode flows', () => {
     expect(apply).toHaveBeenCalled();
   });
 
+  it('allows WatchPlugins to override internal plugins', async () => {
+    const run = jest.fn(() => Promise.resolve());
+    const pluginPath = `${__dirname}/__fixtures__/plugin_path_override`;
+    jest.doMock(
+      pluginPath,
+      () =>
+        class WatchPlugin {
+          constructor() {
+            this.run = run;
+          }
+          getUsageInfo() {
+            return {
+              key: 'p'.codePointAt(0),
+              prompt: 'custom "P" plugin',
+            };
+          }
+        },
+      {virtual: true},
+    );
+
+    watch(
+      Object.assign({}, globalConfig, {
+        rootDir: __dirname,
+        watchPlugins: [pluginPath],
+      }),
+      contexts,
+      pipe,
+      hasteMapInstances,
+      stdin,
+    );
+
+    await nextTick();
+
+    expect(pipe.write.mock.calls.reverse()[0]).toMatchSnapshot();
+
+    stdin.emit(toHex('p'));
+    await nextTick();
+
+    expect(run).toHaveBeenCalled();
+  });
+
   it('allows WatchPlugins to hook into file system changes', async () => {
     const fileChange = jest.fn();
     const pluginPath = `${__dirname}/__fixtures__/plugin_path_fs_change`;

packages/jest-cli/src/lib/watch_plugins_helpers.js

@@ -0,0 +1,51 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. 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.
+ *
+ * @flow
+ */
+import type {GlobalConfig} from 'types/Config';
+import type {WatchPlugin, UsageData} from '../types';
+
+export const filterInteractivePlugins = (
+  watchPlugins: Array<WatchPlugin>,
+  globalConfig: GlobalConfig,
+): Array<WatchPlugin> => {
+  const usageInfos = watchPlugins.map(
+    p => p.getUsageInfo && p.getUsageInfo(globalConfig),
+  );
+
+  return watchPlugins.filter((plugin, i, array) => {
+    if (usageInfos[i]) {
+      const {key} = usageInfos[i];
+      return !usageInfos.slice(i + 1).some(u => u && key === u.key);
+    }
+
+    return false;
+  });
+};
+
+export const getSortedUsageRows = (
+  watchPlugins: Array<WatchPlugin>,
+  globalConfig: GlobalConfig,
+): Array<UsageData> => {
+  return filterInteractivePlugins(watchPlugins, globalConfig)
+    .sort((a: WatchPlugin, b: WatchPlugin) => {
+      if (a.isInternal) {
+        return -1;
+      }
+
+      const usageInfoA = a.getUsageInfo && a.getUsageInfo(globalConfig);
+      const usageInfoB = b.getUsageInfo && b.getUsageInfo(globalConfig);
+
+      if (usageInfoA && usageInfoB) {
+        return usageInfoA.key - usageInfoB.key;
+      }
+
+      return 0;
+    })
+    .map(p => p.getUsageInfo && p.getUsageInfo(globalConfig))
+    .filter(Boolean);
+};

packages/jest-cli/src/plugins/quit.js

@@ -9,6 +9,16 @@
 import BaseWatchPlugin from '../base_watch_plugin';
 
 class QuitPlugin extends BaseWatchPlugin {
+  isInternal: true;
+
+  constructor(options: {
+    stdin: stream$Readable | tty$ReadStream,
+    stdout: stream$Writable | tty$WriteStream,
+  }) {
+    super(options);
+    this.isInternal = true;
+  }
+
   async run() {
     if (typeof this._stdin.setRawMode === 'function') {
       this._stdin.setRawMode(false);

packages/jest-cli/src/plugins/test_name_pattern.js

@@ -14,13 +14,15 @@ import Prompt from '../lib/Prompt';
 
 class TestNamePatternPlugin extends BaseWatchPlugin {
   _prompt: Prompt;
+  isInternal: true;
 
   constructor(options: {
     stdin: stream$Readable | tty$ReadStream,
     stdout: stream$Writable | tty$WriteStream,
   }) {
     super(options);
     this._prompt = new Prompt();
+    this.isInternal = true;
   }
 
   getUsageInfo() {

packages/jest-cli/src/plugins/test_path_pattern.js

@@ -15,13 +15,15 @@ import Prompt from '../lib/Prompt';
 
 class TestPathPatternPlugin extends BaseWatchPlugin {
   _prompt: Prompt;
+  isInternal: true;
 
   constructor(options: {
     stdin: stream$Readable | tty$ReadStream,
     stdout: stream$Writable | tty$WriteStream,
   }) {
     super(options);
     this._prompt = new Prompt();
+    this.isInternal = true;
   }
 
   getUsageInfo() {

packages/jest-cli/src/plugins/update_snapshots.js

@@ -12,6 +12,16 @@ import type {JestHookSubscriber} from '../jest_hooks';
 
 class UpdateSnapshotsPlugin extends BaseWatchPlugin {
   _hasSnapshotFailure: boolean;
+  isInternal: true;
+
+  constructor(options: {
+    stdin: stream$Readable | tty$ReadStream,
+    stdout: stream$Writable | tty$WriteStream,
+  }) {
+    super(options);
+    this.isInternal = true;
+  }
+
   run(
     globalConfig: GlobalConfig,
     updateConfigAndRun: Function,

packages/jest-cli/src/plugins/update_snapshots_interactive.js

@@ -14,7 +14,9 @@ import SnapshotInteractiveMode from '../snapshot_interactive_mode';
 
 class UpdateSnapshotInteractivePlugin extends BaseWatchPlugin {
   _snapshotInteractiveMode: SnapshotInteractiveMode;
+  _failedSnapshotTestPaths: Array<*>;
   _failedSnapshotTestAssertions: Array<AssertionLocation>;
+  isInternal: true;
 
   constructor(options: {
     stdin: stream$Readable | tty$ReadStream,
@@ -23,6 +25,7 @@ class UpdateSnapshotInteractivePlugin extends BaseWatchPlugin {
     super(options);
     this._failedSnapshotTestAssertions = [];
     this._snapshotInteractiveMode = new SnapshotInteractiveMode(this._stdout);
+    this.isInternal = true;
   }
 
   getFailedSnapshotTestAssertions(

packages/jest-cli/src/types.js

@@ -19,6 +19,7 @@ export type JestHooks = {
 };
 
 export interface WatchPlugin {
+  +isInternal?: boolean;
   +apply?: (hooks: JestHookSubscriber) => void;
   +getUsageInfo?: (globalConfig: GlobalConfig) => ?UsageData;
   +onKey?: (value: string) => void;

packages/jest-cli/src/watch.js

@@ -33,6 +33,10 @@ import TestNamePatternPlugin from './plugins/test_name_pattern';
 import UpdateSnapshotsPlugin from './plugins/update_snapshots';
 import UpdateSnapshotsInteractivePlugin from './plugins/update_snapshots_interactive';
 import QuitPlugin from './plugins/quit';
+import {
+  getSortedUsageRows,
+  filterInteractivePlugins,
+} from './lib/watch_plugins_helpers';
 import activeFilters from './lib/active_filters_message';
 
 let hasExitListener = false;
@@ -45,24 +49,6 @@ const INTERNAL_PLUGINS = [
   QuitPlugin,
 ];
 
-const getSortedUsageRows = (
-  watchPlugins: Array<WatchPlugin>,
-  globalConfig: GlobalConfig,
-) => {
-  const internalPlugins = watchPlugins
-    .slice(0, INTERNAL_PLUGINS.length)
-    .map(p => p.getUsageInfo && p.getUsageInfo(globalConfig))
-    .filter(Boolean);
-
-  const thirdPartyPlugins = watchPlugins
-    .slice(INTERNAL_PLUGINS.length)
-    .map(p => p.getUsageInfo && p.getUsageInfo(globalConfig))
-    .filter(Boolean)
-    .sort((a, b) => a.key - b.key);
-
-  return internalPlugins.concat(thirdPartyPlugins);
-};
-
 export default function watch(
   initialGlobalConfig: GlobalConfig,
   contexts: Array<Context>,
@@ -285,7 +271,10 @@ export default function watch(
       return;
     }
 
-    const matchingWatchPlugin = watchPlugins.find(plugin => {
+    const matchingWatchPlugin = filterInteractivePlugins(
+      watchPlugins,
+      globalConfig,
+    ).find(plugin => {
       const usageData =
         (plugin.getUsageInfo && plugin.getUsageInfo(globalConfig)) || {};
       return usageData.key === parseInt(key, 16);