From c919bb80d4aa0436c6f7c645bad4d9f7a31eec22 Mon Sep 17 00:00:00 2001
From: Adam Byrne <misterbyrne@gmail.com>
Date: Mon, 27 Nov 2017 12:40:09 +0000
Subject: [PATCH 1/4] Add failing tests

---
 lib/spring/test/acceptance_test.rb | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/lib/spring/test/acceptance_test.rb b/lib/spring/test/acceptance_test.rb
index c3da1ce7..a6def602 100644
--- a/lib/spring/test/acceptance_test.rb
+++ b/lib/spring/test/acceptance_test.rb
@@ -194,6 +194,23 @@ def self.omg
         assert_success app.spring_test_command
       end
 
+      test "deleting the app root should kill the server" do
+        app.run app.spring_test_command
+        assert spring_env.server_running?, "The server should be running but it isn't"
+        FileUtils.rm_rf(app.root)
+        sleep 2 # wait for the watcher to notice and react
+        assert !spring_env.server_running?, "The server should not be running but it is"
+      end
+
+      test "server restarts when the app root is deleted and recreated" do
+        assert_success app.spring_test_command
+        FileUtils.rm_rf(app.root)
+        sleep 1 # wait for the watcher to notice and react
+
+        generator.copy_to(app.root)
+        assert_success app.spring_test_command
+      end
+
       test "stop command kills server" do
         app.run app.spring_test_command
         assert spring_env.server_running?, "The server should be running but it isn't"

From 82d3bacf7d1977f3cd5e3b2a40590421f4220d20 Mon Sep 17 00:00:00 2001
From: Adam Byrne <misterbyrne@gmail.com>
Date: Mon, 27 Nov 2017 12:41:01 +0000
Subject: [PATCH 2/4] Check if child process is alive

---
 lib/spring/application_manager.rb | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/spring/application_manager.rb b/lib/spring/application_manager.rb
index ca4671fb..f790e337 100644
--- a/lib/spring/application_manager.rb
+++ b/lib/spring/application_manager.rb
@@ -32,7 +32,11 @@ def restart
     end
 
     def alive?
-      @pid
+      return false if @pid.nil?
+      Process.getpgid(@pid)
+      true
+    rescue Errno::ESRCH
+      false
     end
 
     def with_child

From f1300eb2c2a2d487ba250241738f044a858eea0c Mon Sep 17 00:00:00 2001
From: Adam Byrne <misterbyrne@gmail.com>
Date: Mon, 27 Nov 2017 12:43:12 +0000
Subject: [PATCH 3/4] Check if the child app is still alive

---
 lib/spring/application_manager.rb | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/lib/spring/application_manager.rb b/lib/spring/application_manager.rb
index f790e337..770bd47e 100644
--- a/lib/spring/application_manager.rb
+++ b/lib/spring/application_manager.rb
@@ -113,10 +113,20 @@ def start_child(preload = false)
         )
       end
 
-      start_wait_thread(pid, child) if child.gets
+      wait_for_child_to_boot
+      start_wait_thread(pid, child)
       child_socket.close
     end
 
+    def wait_for_child_to_boot
+      timeout = 1
+      loop do
+        break if IO.select([child], nil, nil, timeout)
+        raise "child has exited unexpectedly" unless alive?
+      end
+      child.gets
+    end
+
     def start_wait_thread(pid, child)
       Process.detach(pid)
 

From a44232f05bea1ad8594449dfa27eddc5fde34e50 Mon Sep 17 00:00:00 2001
From: Adam Byrne <misterbyrne@gmail.com>
Date: Mon, 4 Dec 2017 09:19:19 +0000
Subject: [PATCH 4/4] Stop the server if we cannot start a child

---
 lib/spring/application_manager.rb | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/spring/application_manager.rb b/lib/spring/application_manager.rb
index 770bd47e..ae9795ac 100644
--- a/lib/spring/application_manager.rb
+++ b/lib/spring/application_manager.rb
@@ -115,6 +115,10 @@ def start_child(preload = false)
 
       wait_for_child_to_boot
       start_wait_thread(pid, child)
+    rescue => e
+      log "error while starting child: #{e.message}"
+      abort("error while starting child: #{e.message}")
+    ensure
       child_socket.close
     end