From bbe410e6f257ae45e65ca97c708118c8d7ec01ce Mon Sep 17 00:00:00 2001
From: Loonride <knagaitsev1@gmail.com>
Date: Thu, 8 Aug 2019 05:41:14 -0500
Subject: [PATCH] fix(server): fix setupExitSignals usage (#2181)

* fix(server): pass server data to exit signal setup as object

* test(server): add exit signal tests

* style(test): fix lint problem
---
 bin/webpack-dev-server.js                  | 11 ++++-
 lib/utils/setupExitSignals.js              |  6 +--
 test/server/utils/setupExitSignals.test.js | 57 ++++++++++++++++++++++
 3 files changed, 69 insertions(+), 5 deletions(-)
 create mode 100644 test/server/utils/setupExitSignals.test.js

diff --git a/bin/webpack-dev-server.js b/bin/webpack-dev-server.js
index 7c3456f5d3..286cad93b9 100755
--- a/bin/webpack-dev-server.js
+++ b/bin/webpack-dev-server.js
@@ -19,8 +19,14 @@ const getVersions = require('../lib/utils/getVersions');
 const options = require('./options');
 
 let server;
-
-setupExitSignals(server);
+const serverData = {
+  server: null,
+};
+// we must pass an object that contains the server object as a property so that
+// we can update this server property later, and setupExitSignals will be able to
+// recognize that the server has been instantiated, because we will set
+// serverData.server to the new server object.
+setupExitSignals(serverData);
 
 // Prefer the local installation of webpack-dev-server
 if (importLocal(__filename)) {
@@ -98,6 +104,7 @@ function startDevServer(config, options) {
 
   try {
     server = new Server(compiler, options, log);
+    serverData.server = server;
   } catch (err) {
     if (err.name === 'ValidationError') {
       log.error(colors.error(options.stats.colors, err.message));
diff --git a/lib/utils/setupExitSignals.js b/lib/utils/setupExitSignals.js
index 786fc6b2f3..105b2b4273 100644
--- a/lib/utils/setupExitSignals.js
+++ b/lib/utils/setupExitSignals.js
@@ -2,11 +2,11 @@
 
 const signals = ['SIGINT', 'SIGTERM'];
 
-function setupExitSignals(server) {
+function setupExitSignals(serverData) {
   signals.forEach((signal) => {
     process.on(signal, () => {
-      if (server) {
-        server.close(() => {
+      if (serverData.server) {
+        serverData.server.close(() => {
           // eslint-disable-next-line no-process-exit
           process.exit();
         });
diff --git a/test/server/utils/setupExitSignals.test.js b/test/server/utils/setupExitSignals.test.js
new file mode 100644
index 0000000000..0f6f835591
--- /dev/null
+++ b/test/server/utils/setupExitSignals.test.js
@@ -0,0 +1,57 @@
+'use strict';
+
+const setupExitSignals = require('../../../lib/utils/setupExitSignals');
+
+describe('setupExitSignals', () => {
+  let server;
+  let exitSpy;
+  const signals = ['SIGINT', 'SIGTERM'];
+
+  beforeAll(() => {
+    exitSpy = jest.spyOn(process, 'exit').mockImplementation(() => {});
+    server = {
+      close: jest.fn((callback) => {
+        callback();
+      }),
+    };
+  });
+
+  afterEach(() => {
+    exitSpy.mockReset();
+    server.close.mockClear();
+    signals.forEach((signal) => {
+      process.removeAllListeners(signal);
+    });
+  });
+
+  signals.forEach((signal) => {
+    it(`should exit process (${signal}, server never defined)`, (done) => {
+      setupExitSignals({
+        server: null,
+      });
+      process.emit(signal);
+      setTimeout(() => {
+        expect(exitSpy.mock.calls.length).toEqual(1);
+        done();
+      }, 1000);
+    });
+
+    it(`should close server, then exit process (${signal}, server defined before signal)`, (done) => {
+      const serverData = {
+        server: null,
+      };
+      setupExitSignals(serverData);
+
+      setTimeout(() => {
+        serverData.server = server;
+        process.emit(signal);
+      }, 500);
+
+      setTimeout(() => {
+        expect(server.close.mock.calls.length).toEqual(1);
+        expect(exitSpy.mock.calls.length).toEqual(1);
+        done();
+      }, 1500);
+    });
+  });
+});