From 40b385601152e27509e9c5a6c3190e35d9a85e67 Mon Sep 17 00:00:00 2001
From: Nicolas Rodriguez <nico@nicoladmin.fr>
Date: Tue, 30 Dec 2025 15:33:04 +0100
Subject: [PATCH 1/2] feat: add simplecov gem

---
 Gemfile                | 1 +
 gemfiles/ar_71.gemfile | 1 +
 gemfiles/ar_72.gemfile | 1 +
 gemfiles/ar_80.gemfile | 1 +
 gemfiles/ar_81.gemfile | 1 +
 test/test_helper.rb    | 9 +++++++--
 6 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/Gemfile b/Gemfile
index 305ae1d..555191b 100644
--- a/Gemfile
+++ b/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
diff --git a/gemfiles/ar_71.gemfile b/gemfiles/ar_71.gemfile
index 9b1a525..3e6ba1e 100644
--- a/gemfiles/ar_71.gemfile
+++ b/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
diff --git a/gemfiles/ar_72.gemfile b/gemfiles/ar_72.gemfile
index a0a5470..85139bb 100644
--- a/gemfiles/ar_72.gemfile
+++ b/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
diff --git a/gemfiles/ar_80.gemfile b/gemfiles/ar_80.gemfile
index 187b4a6..3830ca1 100644
--- a/gemfiles/ar_80.gemfile
+++ b/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
diff --git a/gemfiles/ar_81.gemfile b/gemfiles/ar_81.gemfile
index 9d3fb58..cdac364 100644
--- a/gemfiles/ar_81.gemfile
+++ b/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
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 389faf3..a96d579 100644
--- a/test/test_helper.rb
+++ b/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"

From edc82ece0d62c8770a6cc4365d180f43033d7be2 Mon Sep 17 00:00:00 2001
From: Nicolas Rodriguez <nico@nicoladmin.fr>
Date: Sat, 10 Jan 2026 17:30:18 +0100
Subject: [PATCH 2/2] Fix
 https://github.com/discourse/prometheus_exporter/issues/364

---
 lib/prometheus_exporter/server/web_server.rb | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/lib/prometheus_exporter/server/web_server.rb b/lib/prometheus_exporter/server/web_server.rb
index b371075..e3130e0 100644
--- a/lib/prometheus_exporter/server/web_server.rb
+++ b/lib/prometheus_exporter/server/web_server.rb
@@ -9,6 +9,14 @@ 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
@@ -16,6 +24,7 @@ def initialize(opts)
       @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