Add at_exit block capturing unexpected termination (#397)

.rubocop_todo.yml

@@ -301,7 +301,7 @@ Metrics/MethodLength:
 # Offense count: 1
 # Configuration parameters: CountComments.
 Metrics/ModuleLength:
-  Max: 111
+  Max: 125
 
 # Offense count: 11
 Metrics/PerceivedComplexity:

lib/bugsnag.rb

@@ -43,6 +43,8 @@ def configure(validate_api_key=true)
       yield(configuration) if block_given?
 
       check_key_valid if validate_api_key
+
+      register_at_exit
     end
 
     ##
@@ -111,6 +113,30 @@ def notify(exception, auto_notify=false, &block)
       end
     end
 
+    ##
+    # Registers an at_exit function to automatically catch errors on exit
+    def register_at_exit
+      return if at_exit_handler_installed?
+      @exit_handler_added = true
+      at_exit do
+        if $!
+          Bugsnag.notify($!, true) do |report|
+            report.severity = 'error'
+            report.severity_reason = {
+              :type => Bugsnag::Report::UNHANDLED_EXCEPTION
+            }
+          end
+        end
+      end
+    end
+
+    ##
+    # Checks if an at_exit handler has been added
+    def at_exit_handler_installed?
+      @exit_handler_added ||= false
+    end
+
+    # Configuration getters
     ##
     # Returns the client's Configuration object, or creates one if not yet created.
     def configuration

lib/bugsnag/integrations/railtie.rb

@@ -17,23 +17,6 @@ class Railtie < Rails::Railtie
       load "bugsnag/tasks/bugsnag.rake"
     end
 
-    # send notifications if a command fails in a 'rails runner' call
-    if self.respond_to? :runner
-      runner do
-        at_exit do
-          if $!
-            Bugsnag.notify($!, true) do |report|
-              report.severity = "error"
-              report.severity_reason = {
-                :type => Bugsnag::Report::UNHANDLED_EXCEPTION_MIDDLEWARE,
-                :attributes => FRAMEWORK_ATTRIBUTES
-              }
-            end
-          end
-        end
-      end
-    end
-
     config.before_initialize do
       # Configure bugsnag rails defaults
       # Skipping API key validation as the key may be set later in an

spec/bugsnag_spec.rb

@@ -17,6 +17,62 @@
     end
   end
 
+  describe "add_exit_handler" do
+
+    before do
+      Bugsnag.instance_variable_set(:@exit_handler_added, false)
+    end
+
+    it "automatically adds an exit handler" do
+      expect(Bugsnag).to receive(:register_at_exit)
+      Bugsnag.configure do |conf|
+        conf.api_key = "TEST KEY"
+      end
+    end
+
+    it "calls at_exit when register_at_exit is called" do
+      expect(Bugsnag).to receive(:at_exit)
+      Bugsnag.register_at_exit
+    end
+
+    it "doesn't call at_exit on subsequent calls" do
+      expect(Bugsnag).to receive(:at_exit).once
+      Bugsnag.register_at_exit
+      Bugsnag.register_at_exit
+    end
+
+    context 'with aliased at_exit' do
+      before do
+        module Kernel
+          alias_method :old_at_exit, :at_exit
+          def at_exit
+            begin
+              raise BugsnagTestException.new("Oh no")
+            rescue
+              yield
+            end
+          end
+        end
+      end
+
+      it "sends an exception when at_exit is called" do
+        report_mock = double('report')
+        expect(report_mock).to receive(:severity=).with('error')
+        expect(report_mock).to receive(:severity_reason=).with({
+          :type => Bugsnag::Report::UNHANDLED_EXCEPTION
+        })
+        expect(Bugsnag).to receive(:notify).with(kind_of(BugsnagTestException), true).and_yield(report_mock)
+        Bugsnag.register_at_exit
+      end
+
+      after do
+        module Kernel
+          alias_method :at_exit, :old_at_exit
+        end
+      end
+    end
+  end
+
   describe 'loading integrations' do
     before do
       module Kernel

spec/configuration_spec.rb

@@ -221,4 +221,5 @@ def debug(name, &block)
   it "should have exit exception classes ignored by default" do
     expect(subject.ignore_classes).to eq(Set.new([SystemExit, Interrupt]))
   end
+
 end