add Lamian::SidekiqRavenMiddleware spec + minor fixes

lib/lamian/engine.rb

@@ -10,7 +10,9 @@ class Engine < ::Rails::Engine
     paths["app/views"] << "lib/lamian/rails_views"
 
     initializer "lamian.use_rack_middleware" do |app|
+      # :nocov:
       app.config.middleware.unshift(Lamian::Middleware)
+      # :nocov:
     end
   end
 end

lib/lamian/raven_context_extension.rb

@@ -5,7 +5,8 @@ module Lamian::RavenContextExtension
   # Adds current lamian log to the extra part of all raven events generated inside Lamian.run block
   # @see https://www.rubydoc.info/gems/sentry-raven/0.9.2/Raven/Context#extra-instance_method
   def extra
-    log = Lamian.dump(format: :txt) or return super
+    log = Lamian.dump(format: :txt)
+    return super unless log
     extra = super || {}
     extra.merge(lamian_log: log)
   end

spec/lamian/raven_context_extension_spec.rb

@@ -29,7 +29,7 @@
   context "outside of Lamian.run block" do
     it "doesn't add lamian log" do
       Raven.capture_message("msg")
-      expect(extra_info["lamian_log"]).to eq(nil)
+      expect(extra_info).not_to have_key("lamian_log")
     end
   end
 end

spec/lamian/sidekiq_raven_middleware_spec.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+describe Lamian::SidekiqRavenMiddleware, :cool_loggers do
+  it "call Raven.extra_context with proper lamian_log" do
+    expect(Raven).to receive(:extra_context).with(lamian_log: "some log\n")
+
+    middleware_call = proc do
+      Lamian::SidekiqRavenMiddleware.new.call do
+        generic_logger.info "some log"
+        raise "some error"
+      end
+    end
+
+    expect(middleware_call).to raise_error(RuntimeError, "some error")
+  end
+end