From bc6b82512856d88f7e0bebd4f31fab38ec129b83 Mon Sep 17 00:00:00 2001
From: Evan Phoenix <evan@fallingsnow.net>
Date: Fri, 31 May 2013 09:59:45 -0700
Subject: [PATCH] Error out early if there is no app configured

---
 lib/puma/cli.rb           | 10 ++++++++++
 lib/puma/configuration.rb | 11 +++++++++++
 2 files changed, 21 insertions(+)

diff --git a/lib/puma/cli.rb b/lib/puma/cli.rb
index e0f70892..e0f5d5e9 100644
--- a/lib/puma/cli.rb
+++ b/lib/puma/cli.rb
@@ -419,6 +419,11 @@ module Puma
 
       @binder.parse @options[:binds], self
 
+      unless @config.app_configured?
+        error "No application configured, nothing to run"
+        exit 1
+      end
+
       if @options[:daemon]
         Process.daemon(true, @io_redirected)
       end
@@ -651,6 +656,11 @@ module Puma
 
       @binder.parse @options[:binds], self
 
+      unless @config.app_configured?
+        error "No application configured, nothing to run"
+        exit 1
+      end
+
       read, write = Puma::Util.pipe
 
       Signal.trap "SIGCHLD" do
diff --git a/lib/puma/configuration.rb b/lib/puma/configuration.rb
index 3d14cafd..418f3b10 100644
--- a/lib/puma/configuration.rb
+++ b/lib/puma/configuration.rb
@@ -67,6 +67,17 @@ module Puma
       end
     end
 
+    # Indicate if there is a properly configured app
+    #
+    def app_configured?
+      return true if @options[:app]
+      if path = @options[:rackup]
+        return File.exists?(path)
+      end
+
+      false
+    end
+
     # Load the specified rackup file, pull an options from
     # the rackup file, and set @app.
     #