From 97efad806657333aa12ad8f08d2a2cafef924699 Mon Sep 17 00:00:00 2001
From: Ivan Chernov <vanyaz158@gmail.com>
Date: Tue, 28 Sep 2021 17:01:23 +0300
Subject: [PATCH 1/2] Fix accessing to config attrs

---
 .rspec                                        |  3 ++
 bc-prometheus-ruby.gemspec                    |  1 +
 .../prometheus/instrumentors/web.rb           |  8 +++-
 .../prometheus/instrumentors/web_spec.rb      | 40 +++++++++++++++++++
 spec/spec_helper.rb                           |  1 +
 5 files changed, 51 insertions(+), 2 deletions(-)
 create mode 100644 .rspec
 create mode 100644 spec/bigcommerce/prometheus/instrumentors/web_spec.rb

diff --git a/.rspec b/.rspec
new file mode 100644
index 0000000..34c5164
--- /dev/null
+++ b/.rspec
@@ -0,0 +1,3 @@
+--format documentation
+--color
+--require spec_helper
diff --git a/bc-prometheus-ruby.gemspec b/bc-prometheus-ruby.gemspec
index 016dfe7..378eea9 100644
--- a/bc-prometheus-ruby.gemspec
+++ b/bc-prometheus-ruby.gemspec
@@ -36,6 +36,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'bundler-audit', '>= 0.6'
   spec.add_development_dependency 'null-logger', '>= 0.1'
   spec.add_development_dependency 'pry', '>= 0.12'
+  spec.add_development_dependency 'railties', '>= 6.0.0'
   spec.add_development_dependency 'rake', '>= 10.0'
   spec.add_development_dependency 'rspec', '>= 3.8'
   spec.add_development_dependency 'rspec_junit_formatter', '>= 0.4'
diff --git a/lib/bigcommerce/prometheus/instrumentors/web.rb b/lib/bigcommerce/prometheus/instrumentors/web.rb
index d37b7af..72ca2d3 100644
--- a/lib/bigcommerce/prometheus/instrumentors/web.rb
+++ b/lib/bigcommerce/prometheus/instrumentors/web.rb
@@ -62,7 +62,7 @@ def server
         end
 
         def setup_before_fork
-          @app.config.before_fork_callbacks = [] unless @app.config.before_fork_callbacks
+          @app.config.before_fork_callbacks = [] unless config_defined?(:before_fork_callbacks)
           @app.config.before_fork_callbacks << lambda do
             server.add_type_collector(PrometheusExporter::Server::ActiveRecordCollector.new)
             server.add_type_collector(PrometheusExporter::Server::WebCollector.new)
@@ -75,13 +75,17 @@ def setup_before_fork
         end
 
         def setup_after_fork
-          @app.config.after_fork_callbacks = [] unless @app.config.after_fork_callbacks
+          @app.config.after_fork_callbacks = [] unless config_defined?(:after_fork_callbacks)
           @app.config.after_fork_callbacks << lambda do
             ::Bigcommerce::Prometheus::Integrations::Puma.start(client: Bigcommerce::Prometheus.client)
             @collectors.each(&:start)
           end
         end
 
+        def config_defined?(config_name)
+          @app.config.respond_to?(config_name) && @app.config.public_send(config_name)
+        end
+
         def setup_middleware
           @app.middleware.unshift(PrometheusExporter::Middleware, client: Bigcommerce::Prometheus.client)
         rescue StandardError => e
diff --git a/spec/bigcommerce/prometheus/instrumentors/web_spec.rb b/spec/bigcommerce/prometheus/instrumentors/web_spec.rb
new file mode 100644
index 0000000..c3c13a3
--- /dev/null
+++ b/spec/bigcommerce/prometheus/instrumentors/web_spec.rb
@@ -0,0 +1,40 @@
+describe Bigcommerce::Prometheus::Instrumentors::Web do
+  def run!
+    described_class.new(app: application).start
+  end
+
+  let(:application) do
+    instance_double(Rails::Application).tap do |instance|
+      allow(instance).to receive(:config).and_return(configuration)
+      allow(instance).to receive(:middleware).and_return(middleware)
+    end
+  end
+
+  let(:configuration) { Rails::Engine::Configuration.new }
+  let(:middleware) { [] }
+
+  it 'properly handles lack of the fork configs' do
+    expect(Bigcommerce::Prometheus.logger).not_to receive(:error)
+
+    run!
+
+    expect(configuration.respond_to?(:before_fork_callbacks)).to eq(true)
+    expect(configuration.respond_to?(:after_fork_callbacks)).to eq(true)
+    expect(configuration.before_fork_callbacks).to be_an_instance_of(Array)
+    expect(configuration.after_fork_callbacks).to be_an_instance_of(Array)
+  end
+
+  context 'when configuration already set' do
+    before do
+      configuration.before_fork_callbacks = [1]
+      configuration.after_fork_callbacks = [1]
+    end
+
+    it 'just adds another elements' do
+      run!
+
+      expect(configuration.before_fork_callbacks.size).to eq(2)
+      expect(configuration.after_fork_callbacks.size).to eq(2)
+    end
+  end
+end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 07e6061..9b0b19c 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -18,6 +18,7 @@
 require_relative 'simplecov_helper'
 require 'bigcommerce/prometheus'
 require 'pry'
+require 'rails'
 Dir["#{File.join(File.dirname(__FILE__), 'support')}/**/*.rb"].sort.each { |f| require f }
 
 RSpec.configure do |config|

From 767d3080ea63a0ed354b4420673692ab18437d48 Mon Sep 17 00:00:00 2001
From: Ivan Chernov <vanyaz158@gmail.com>
Date: Tue, 28 Sep 2021 17:05:53 +0300
Subject: [PATCH 2/2] Remove documentation format

---
 .rspec | 1 -
 1 file changed, 1 deletion(-)

diff --git a/.rspec b/.rspec
index 34c5164..83e16f8 100644
--- a/.rspec
+++ b/.rspec
@@ -1,3 +1,2 @@
---format documentation
 --color
 --require spec_helper