Add simplecov gem

Gemfile

@@ -20,6 +20,7 @@ gem "redis"
 gem "syntax_tree"
 gem "syntax_tree-disable_ternary"
 gem "raindrops", "~> 0.19" if !RUBY_ENGINE == "jruby"
+gem "simplecov"
 
 # Dev tools / linter
 gem "guard", require: false

gemfiles/ar_71.gemfile

@@ -16,6 +16,7 @@ gem "rake"
 gem "redis"
 gem "syntax_tree"
 gem "syntax_tree-disable_ternary"
+gem "simplecov"
 gem "guard", require: false
 gem "guard-minitest", require: false
 gem "rubocop", require: false

gemfiles/ar_72.gemfile

@@ -16,6 +16,7 @@ gem "rake"
 gem "redis"
 gem "syntax_tree"
 gem "syntax_tree-disable_ternary"
+gem "simplecov"
 gem "guard", require: false
 gem "guard-minitest", require: false
 gem "rubocop", require: false

gemfiles/ar_80.gemfile

@@ -16,6 +16,7 @@ gem "rake"
 gem "redis"
 gem "syntax_tree"
 gem "syntax_tree-disable_ternary"
+gem "simplecov"
 gem "guard", require: false
 gem "guard-minitest", require: false
 gem "rubocop", require: false

gemfiles/ar_81.gemfile

@@ -16,6 +16,7 @@ gem "rake"
 gem "redis"
 gem "syntax_tree"
 gem "syntax_tree-disable_ternary"
+gem "simplecov"
 gem "guard", require: false
 gem "guard-minitest", require: false
 gem "rubocop", require: false

lib/prometheus_exporter/server/web_server.rb

@@ -9,13 +9,22 @@ module PrometheusExporter::Server
   class WebServer
     attr_reader :collector
 
+    PAGESIZE =
+      begin
+        `getconf PAGESIZE`.to_i
+      rescue StandardError
+        4096
+      end
+    private_constant :PAGESIZE
+
     def initialize(opts)
       @port = opts[:port] || PrometheusExporter::DEFAULT_PORT
       @bind = opts[:bind] || PrometheusExporter::DEFAULT_BIND_ADDRESS
       @timeout = opts[:timeout] || PrometheusExporter::DEFAULT_TIMEOUT
       @verbose = opts[:verbose] || false
       @auth = opts[:auth]
       @realm = opts[:realm] || PrometheusExporter::DEFAULT_REALM
+      @pid = Process.pid
 
       @metrics_total =
         PrometheusExporter::Metric::Counter.new(
@@ -173,15 +182,8 @@ def metrics
     end
 
     def get_rss
-      @pagesize ||=
-        begin
-          `getconf PAGESIZE`.to_i
-        rescue StandardError
-          4096
-        end
-      @pid ||= Process.pid
       begin
-        File.read("/proc/#{@pid}/statm").split(" ")[1].to_i * @pagesize
+        File.read("/proc/#{@pid}/statm").split(" ")[1].to_i * PAGESIZE
       rescue StandardError
         0
       end

test/test_helper.rb

@@ -1,7 +1,9 @@
 # frozen_string_literal: true
 
-$LOAD_PATH.unshift File.expand_path("../../lib", __FILE__)
-require "prometheus_exporter"
+require "simplecov"
+
+# Start SimpleCov
+SimpleCov.start { add_filter "test/" }
 
 require "minitest/mock"
 require "minitest/autorun"
@@ -126,3 +128,6 @@ def get_max_metric_age
 
 # Allow stubbing process monotonic clock from any class in the suite
 Minitest::Test.send(:include, ClockHelper)
+
+# Load our gem
+require "prometheus_exporter"