FIX: kwargs patching (#313)

Amends method profiler patching to use Ruby 3.0 patterns and enforces Ruby 3.0 and up.

.rubocop

@@ -0,0 +1 @@
+--ignore-unrecognized-cops

.rubocop.yml

@@ -4,4 +4,11 @@ inherit_gem:
 AllCops:
   Exclude:
     - 'gemfiles/**/*'
-    - 'vendor/**/*'
+    - 'vendor/**/*'
+
+Discourse/Plugins/NoMonkeyPatching:
+  Enabled: false
+
+Discourse/Plugins/NamespaceMethods:
+  Exclude:
+    - bin/prometheus_exporter

README.md

@@ -40,7 +40,7 @@ To learn more see [Instrumenting Rails with Prometheus](https://samsaffron.com/a
 
 ## Requirements
 
-Minimum Ruby of version 2.6.0 is required, Ruby 2.5.0 is EOL as of March 31st 2021.
+Minimum Ruby of version 3.0.0 is required, Ruby 2.7 is EOL as of March 31st 2023.
 
 ## Migrating from v0.x
 
@@ -884,7 +884,7 @@ prometheus_exporter -p 8080 \
                     --prefix 'foo_'
 ```
 
-You can use `-b` option to bind the `prometheus_exporter` web server to any IPv4 interface with `-b 0.0.0.0`, 
+You can use `-b` option to bind the `prometheus_exporter` web server to any IPv4 interface with `-b 0.0.0.0`,
 any IPv6 interface with `-b ::`, or `-b ANY` to any IPv4/IPv6 interfaces available on your host system.
 
 #### Enabling Basic Authentication

gemfiles/ar_70.gemfile

@@ -2,4 +2,6 @@
 
 source "https://rubygems.org"
 
+gem "activerecord", "~> 7.0.0"
+
 gemspec path: "../"

lib/prometheus_exporter/instrumentation/method_profiler.rb

@@ -44,7 +44,7 @@ class PrometheusExporter::Instrumentation::MethodProfiler
     patch_source_line = __LINE__ + 3
     patches = methods.map do |method_name|
       <<~RUBY
-        def #{method_name}(*args, &blk)
+        def #{method_name}(...)
           unless prof = Thread.current[:_method_profiler]
             return super
           end
@@ -75,13 +75,13 @@ class PrometheusExporter::Instrumentation::MethodProfiler
       <<~RUBY
       unless defined?(#{method_name}__mp_unpatched)
         alias_method :#{method_name}__mp_unpatched, :#{method_name}
-        def #{method_name}(*args, &blk)
+        def #{method_name}(...)
           unless prof = Thread.current[:_method_profiler]
-            return #{method_name}__mp_unpatched(*args, &blk)
+            return #{method_name}__mp_unpatched(...)
           end
           begin
             start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
-            #{method_name}__mp_unpatched(*args, &blk)
+            #{method_name}__mp_unpatched(...)
           ensure
             data = (prof[:#{name}] ||= {duration: 0.0, calls: 0})
             data[:duration] += Process.clock_gettime(Process::CLOCK_MONOTONIC) - start

prometheus_exporter.gemspec

@@ -34,7 +34,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "oj", "~> 3.0"
   spec.add_development_dependency "rack-test", "~> 0.8.3"
   spec.add_development_dependency "minitest-stub-const", "~> 0.6"
-  spec.add_development_dependency "rubocop-discourse", ">2"
+  spec.add_development_dependency "rubocop-discourse", ">= 3"
   spec.add_development_dependency "appraisal", "~> 2.3"
   spec.add_development_dependency "activerecord", "~> 6.0.0"
   spec.add_development_dependency "redis", "> 5"
@@ -42,5 +42,5 @@ Gem::Specification.new do |spec|
   if !RUBY_ENGINE == 'jruby'
     spec.add_development_dependency "raindrops", "~> 0.19"
   end
-  spec.required_ruby_version = '>= 2.6.0'
+  spec.required_ruby_version = '>= 3.0.0'
 end

test/instrumentation/method_profiler_test.rb

@@ -22,7 +22,7 @@ class PrometheusInstrumentationMethodProfilerTest < Minitest::Test
   def test_alias_method_source_location
     file, line = SomeClassPatchedUsingAliasMethod.instance_method(:some_method).source_location
     source = File.read(file).lines[line - 1].strip
-    assert_equal 'def #{method_name}(*args, &blk)', source
+    assert_equal 'def #{method_name}(...)', source
   end
 
   def test_alias_method_preserves_behavior
@@ -32,7 +32,7 @@ class PrometheusInstrumentationMethodProfilerTest < Minitest::Test
   def test_prepend_source_location
     file, line = SomeClassPatchedUsingPrepend.instance_method(:some_method).source_location
     source = File.read(file).lines[line - 1].strip
-    assert_equal 'def #{method_name}(*args, &blk)', source
+    assert_equal 'def #{method_name}(...)', source
   end
 
   def test_prepend_preserves_behavior