From 444afa301065a78d252d5358b2b79ebc7635855a Mon Sep 17 00:00:00 2001
From: Tim Seckinger <seckinger.tim@gmail.com>
Date: Mon, 6 May 2019 00:22:07 +0200
Subject: [PATCH] make watch plugin initialization errors look nice

---
 .../__snapshots__/watch.test.js.snap          | 11 +++++++
 .../jest-core/src/__tests__/watch.test.js     | 32 ++++++++++++++++++-
 packages/jest-core/src/watch.ts               | 25 +++++++++++----
 3 files changed, 61 insertions(+), 7 deletions(-)

diff --git a/packages/jest-core/src/__tests__/__snapshots__/watch.test.js.snap b/packages/jest-core/src/__tests__/__snapshots__/watch.test.js.snap
index 85d1828379c5..70a6fe598f14 100644
--- a/packages/jest-core/src/__tests__/__snapshots__/watch.test.js.snap
+++ b/packages/jest-core/src/__tests__/__snapshots__/watch.test.js.snap
@@ -50,6 +50,17 @@ Watch Usage
 ]
 `;
 
+exports[`Watch mode flows makes watch plugin initialization errors look nice 1`] = `
+[Error: Failed to initialize watch plugin '/Users/timseckinger/proj/jest/packages/jest-core/src/__tests__/__fixtures__/plugin_path_throws':
+
+  ● Test suite failed to run
+
+    initialization failure
+
+      at Object.jest.doMock [as user:/Users/timseckinger/proj/jest/packages/jest-core/src/__tests__/__fixtures__/plugin_path_throws:] (watch.test.js:584:15)
+]
+`;
+
 exports[`Watch mode flows shows prompts for WatchPlugins in alphabetical order 1`] = `
 Array [
   Array [
diff --git a/packages/jest-core/src/__tests__/watch.test.js b/packages/jest-core/src/__tests__/watch.test.js
index 3d480a29fc23..8a9e7a0968f4 100644
--- a/packages/jest-core/src/__tests__/watch.test.js
+++ b/packages/jest-core/src/__tests__/watch.test.js
@@ -108,7 +108,12 @@ describe('Watch mode flows', () => {
     isInteractive = true;
     jest.doMock('jest-util/build/isInteractive', () => isInteractive);
     watch = require('../watch').default;
-    const config = {roots: [], testPathIgnorePatterns: [], testRegex: []};
+    const config = {
+      rootDir: __dirname,
+      roots: [],
+      testPathIgnorePatterns: [],
+      testRegex: [],
+    };
     pipe = {write: jest.fn()};
     globalConfig = {watch: true};
     hasteMapInstances = [{on: () => {}}];
@@ -571,6 +576,31 @@ describe('Watch mode flows', () => {
     });
   });
 
+  it('makes watch plugin initialization errors look nice', async () => {
+    const pluginPath = `${__dirname}/__fixtures__/plugin_path_throws`;
+    jest.doMock(
+      pluginPath,
+      () => {
+        throw new Error('initialization failure');
+      },
+      {virtual: true},
+    );
+
+    await expect(
+      watch(
+        {
+          ...globalConfig,
+          rootDir: __dirname,
+          watchPlugins: [{config: {}, path: pluginPath}],
+        },
+        contexts,
+        pipe,
+        hasteMapInstances,
+        stdin,
+      ),
+    ).rejects.toMatchSnapshot();
+  });
+
   it.each`
     ok      | option
     ${'✔︎'} | ${'bail'}
diff --git a/packages/jest-core/src/watch.ts b/packages/jest-core/src/watch.ts
index 2efe8e05b165..5a4c9a891334 100644
--- a/packages/jest-core/src/watch.ts
+++ b/packages/jest-core/src/watch.ts
@@ -171,12 +171,25 @@ export default function watch(
     }
 
     for (const pluginWithConfig of globalConfig.watchPlugins) {
-      const ThirdPartyPlugin = require(pluginWithConfig.path);
-      const plugin: WatchPlugin = new ThirdPartyPlugin({
-        config: pluginWithConfig.config,
-        stdin,
-        stdout: outputStream,
-      });
+      let plugin: WatchPlugin;
+      try {
+        const ThirdPartyPlugin = require(pluginWithConfig.path);
+        plugin = new ThirdPartyPlugin({
+          config: pluginWithConfig.config,
+          stdin,
+          stdout: outputStream,
+        });
+      } catch (err) {
+        return Promise.reject(
+          new Error(
+            `Failed to initialize watch plugin '${
+              pluginWithConfig.path
+            }':\n\n${formatExecError(err, contexts[0].config, {
+              noStackTrace: false,
+            })}`,
+          ),
+        );
+      }
       checkForConflicts(watchPluginKeys, plugin, globalConfig);
 
       const hookSubscriber = hooks.getSubscriber();