Add method coverage support

.github/workflows/main.yml

@@ -18,8 +18,10 @@ jobs:
           - '3.4'
           - '4.0'
           - ruby-head
-          - jruby
+          - jruby-9.4
+          - jruby-10.0
           - jruby-head
+          - truffleruby
 
     steps:
       - uses: actions/checkout@v6
@@ -30,8 +32,8 @@ jobs:
         with:
           ruby-version: ${{ matrix.ruby-version }}
           bundler-cache: true
-        continue-on-error: ${{ (matrix.ruby-version == 'ruby-head') || (matrix.ruby-version == 'jruby-head') }}
+        continue-on-error: ${{ (matrix.ruby-version == 'ruby-head') || (matrix.ruby-version == 'jruby-head') || (matrix.ruby-version == 'truffleruby') }}
 
       - run: |
           bundle exec rake
-        continue-on-error: ${{ (matrix.ruby-version == 'ruby-head') || (matrix.ruby-version == 'jruby-head') }}
+        continue-on-error: ${{ (matrix.ruby-version == 'ruby-head') || (matrix.ruby-version == 'jruby-head') || (matrix.ruby-version == 'truffleruby') }}

.mutant.yml

@@ -0,0 +1,13 @@
+usage: opensource
+integration:
+  name: minitest
+includes:
+  - lib
+  - test
+requires:
+  - simplecov
+  - simplecov-html
+matcher:
+  subjects:
+    - SimpleCov::Formatter::HTMLFormatter#coverage_css_class
+    - SimpleCov::Formatter::HTMLFormatter#strength_css_class

.rubocop.yml

@@ -23,6 +23,7 @@ Metrics/BlockNesting:
   Max: 2
 
 Metrics/ClassLength:
+  Max: 110
   CountAsOne:
     - array
     - hash
@@ -59,3 +60,6 @@ Style/TrailingCommaInHashLiteral:
 
 Style/TrailingCommaInArrayLiteral:
   EnforcedStyleForMultiline: "comma"
+
+Gemspec/RequireMFA:
+  Enabled: false

Gemfile.lock

@@ -1,10 +1,10 @@
 GIT
   remote: https://github.com/simplecov-ruby/simplecov
-  revision: 6bc01182d366be51cbe3a590bede1bd41ac71db8
+  revision: 3d8d723874ff14b06f30dee5d1453f9acc92fdf9
   specs:
     simplecov (0.22.0)
       docile (~> 1.1)
-      simplecov-html (~> 0.11)
+      simplecov-html (~> 0.12)
       simplecov_json_formatter (~> 0.1)
 
 PATH

assets/stylesheets/application.css

@@ -1,3 +1,3 @@
 //= require ./reset.css
 //= require_directory ./plugins/
-//= require ./screen.css
+//= require ./screen.css

assets/stylesheets/screen.css

@@ -488,3 +488,8 @@ thead th {
 #dark-mode-toggle:hover {
   opacity: 0.8;
 }
+
+.t-missed-method-summary ul {
+  margin: 0;
+  padding-left: 2em;
+}

lib/simplecov-html.rb

@@ -23,7 +23,8 @@ class HTMLFormatter
       }.freeze
 
       def initialize
-        @branchable_result = SimpleCov.branch_coverage?
+        @branch_coverage = SimpleCov.branch_coverage?
+        @method_coverage = SimpleCov.method_coverage?
         @templates = {}
         @inline_assets = !ENV["SIMPLECOV_INLINE_ASSETS"].nil?
         @public_assets_dir = File.join(File.dirname(__FILE__), "../public/")
@@ -44,25 +45,32 @@ def format(result)
 
     private
 
-      def branchable_result?
+      def branch_coverage?
         # cached in initialize because we truly look it up a whole bunch of times
         # and it's easier to cache here then in SimpleCov because there we might
         # still enable/disable branch coverage criterion
-        @branchable_result
+        @branch_coverage
+      end
+
+      def method_coverage?
+        # cached in initialize because we truly look it up a whole bunch of times
+        # and it's easier to cache here then in SimpleCov because there we might
+        # still enable/disable branch coverage criterion
+        @method_coverage
       end
 
       def line_status?(source_file, line)
-        branchable_result? && source_file.line_with_missed_branch?(line.number) ? "missed-branch" : line.status
+        branch_coverage? && source_file.line_with_missed_branch?(line.number) ? "missed-branch" : line.status
       end
 
       def output_message(result)
-        output = "Coverage report generated for #{result.command_name} to #{output_path}."
-        output += "\nLine Coverage: #{result.covered_percent.floor(2)}% (#{result.covered_lines} / #{result.total_lines})"
+        parts = []
+        parts << "Coverage report generated for #{result.command_name} to #{output_path}"
+        parts << "Line coverage: #{render_stats(result, :line)}"
+        parts << "Branch coverage: #{render_stats(result, :branch)}" if branch_coverage?
+        parts << "Method coverage: #{render_stats(result, :method)}" if method_coverage?
 
-        if branchable_result?
-          output += "\nBranch Coverage: #{result.coverage_statistics[:branch].percent.floor(2)}% (#{result.covered_branches} / #{result.total_branches})"
-        end
-        output
+        parts.join("\n")
       end
 
       # Returns the an erb instance for the template of given name
@@ -86,6 +94,10 @@ def assets_path(name)
         File.join("./assets", SimpleCov::Formatter::HTMLFormatter::VERSION, name)
       end
 
+      def to_id(value)
+        value.gsub(/^[^a-zA-Z]+/, "").gsub(/[^a-zA-Z0-9\-_]/, "")
+      end
+
       def asset_inline(name)
         path = File.join(@public_assets_dir, name)
         # Equivalent to `Base64.strict_encode64(File.read(path))` but without depending on Base64
@@ -102,11 +114,6 @@ def formatted_source_file(source_file)
 
       # Returns a table containing the given source files
       def formatted_file_list(title, source_files)
-        title_id = title.gsub(/^[^a-zA-Z]+/, "").gsub(/[^a-zA-Z0-9\-_]/, "")
-        # Silence a warning by using the following variable to assign to itself:
-        # "warning: possibly useless use of a variable in void context"
-        # The variable is used by ERB via binding.
-        title_id = title_id # rubocop:disable Lint/SelfAssignment
         template("file_list").result(binding)
       end
 
@@ -150,6 +157,11 @@ def shortened_filename(source_file)
       def link_to_source_file(source_file)
         %(<a href="##{id source_file}" class="src_link" title="#{shortened_filename source_file}">#{shortened_filename source_file}</a>)
       end
+
+      def render_stats(result, criterion)
+        stats = result.coverage_statistics.fetch(criterion)
+        Kernel.format("%<covered>d / %<total>d (%<percent>.2f%%)", covered: stats.covered, total: stats.total, percent: stats.percent)
+      end
     end
   end
 end

test/test_mutation.rb

@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+require "helper"
+
+# Focused tests for mutation testing — exercises private methods directly.
+# Uses cover() to explicitly tell mutant which methods each test covers.
+class TestMutation < Minitest::Test
+  cover "SimpleCov::Formatter::HTMLFormatter#coverage_css_class" if respond_to?(:cover)
+
+  def test_coverage_css_class_green
+    assert_equal "green", formatter.send(:coverage_css_class, 100)
+    assert_equal "green", formatter.send(:coverage_css_class, 91)
+    assert_equal "green", formatter.send(:coverage_css_class, 90.01)
+  end
+
+  def test_coverage_css_class_yellow
+    assert_equal "yellow", formatter.send(:coverage_css_class, 90)
+    assert_equal "yellow", formatter.send(:coverage_css_class, 81)
+    assert_equal "yellow", formatter.send(:coverage_css_class, 80.01)
+  end
+
+  def test_coverage_css_class_red
+    assert_equal "red", formatter.send(:coverage_css_class, 80)
+    assert_equal "red", formatter.send(:coverage_css_class, 50)
+    assert_equal "red", formatter.send(:coverage_css_class, 0)
+  end
+
+  cover "SimpleCov::Formatter::HTMLFormatter#strength_css_class" if respond_to?(:cover)
+
+  def test_strength_css_class_green
+    assert_equal "green", formatter.send(:strength_css_class, 2)
+    assert_equal "green", formatter.send(:strength_css_class, 1.01)
+  end
+
+  def test_strength_css_class_yellow
+    assert_equal "yellow", formatter.send(:strength_css_class, 1)
+    assert_equal "yellow", formatter.send(:strength_css_class, 1.0)
+  end
+
+  def test_strength_css_class_red
+    assert_equal "red", formatter.send(:strength_css_class, 0.99)
+    assert_equal "red", formatter.send(:strength_css_class, 0)
+  end
+
+private
+
+  def formatter
+    @formatter ||= SimpleCov::Formatter::HTMLFormatter.new
+  end
+end

test/test_simple_cov-html.rb

@@ -42,6 +42,15 @@ def test_output
     assert_branch_coverages(html_doc) if RUBY_ENGINE != "jruby"
   end
 
+  def test_output_with_method_coverage
+    return unless SimpleCov.method_coverage_supported?
+
+    SimpleCov.enable_coverage(:method)
+    html_doc = format_results("sample.rb" => CoverageFixtures::SAMPLE_RB)
+
+    assert html_doc.at_css("div#AllFiles div.t-method-summary")
+  end
+
   def test_output_without_branch_coverage
     SimpleCov.clear_coverage_criteria
     html_doc = format_results("sample.rb" => CoverageFixtures::SAMPLE_RB)

views/file_list.erb

@@ -1,4 +1,4 @@
-<div class="file_list_container" id="<%= title_id %>">
+<div class="file_list_container" id="<%= to_id(title) %>">
   <h2>
     <span class="group_name"><%= title %></span>
     (<span class="covered_percent">
@@ -13,7 +13,7 @@
     )
   </h2>
 
-  <a name="<%= title_id %>"></a>
+  <a name="<%= to_id(title) %>"></a>
 
   <div>
     <b><%= source_files.length %></b> files in total.
@@ -25,13 +25,21 @@
     <span class="red"><b><%= source_files.missed_lines %></b> lines missed. </span>
     (<%= covered_percent(source_files.covered_percent) %>)
   </div>
-<%- if branchable_result? -%>
+<%- if branch_coverage? -%>
   <div class="t-branch-summary">
     <span><b><%= source_files.total_branches %></b> total branches, </span>
     <span class="green"><b><%= source_files.covered_branches %></b> branches covered</span> and
     <span class="red"><b><%= source_files.missed_branches %></b> branches missed.</span>
     (<%= covered_percent(source_files.branch_covered_percent) %>)
   </div>
+<%- end -%>
+<%- if method_coverage? -%>
+  <div class="t-method-summary">
+    <span><b><%= source_files.total_methods %></b> total methods, </span>
+    <span class="green"><b><%= source_files.covered_methods %></b> methods covered</span> and
+    <span class="red"><b><%= source_files.missed_methods %></b> methods missed.</span>
+    (<%= covered_percent(source_files.method_covered_percent) %>)
+  </div>
 <%- end -%>
   <div class="file_list--responsive">
     <table class="file_list">
@@ -44,11 +52,17 @@
           <th class="cell--number">Lines covered</th>
           <th class="cell--number">Lines missed</th>
           <th class="cell--number">Avg. Hits / Line</th>
-<%- if branchable_result? -%>
+<%- if branch_coverage? -%>
           <th class="cell--number">Branch Coverage</th>
           <th class="cell--number">Branches</th>
           <th class="cell--number">Covered branches</th>
           <th class="cell--number">Missed branches </th>
+<%- end -%>
+<%- if method_coverage? -%>
+          <th class="cell--number">Method Coverage</th>
+          <th class="cell--number">Methods</th>
+          <th class="cell--number">Covered methods</th>
+          <th class="cell--number">Missed methods </th>
 <%- end -%>
         </tr>
       </thead>
@@ -62,11 +76,17 @@
           <td class="cell--number"><%= source_file.covered_lines.count %></td>
           <td class="cell--number"><%= source_file.missed_lines.count %></td>
           <td class="cell--number"><%= sprintf("%.2f", source_file.covered_strength) %></td>
-<%- if branchable_result? -%>
+<%- if branch_coverage? -%>
           <td class="strong cell--number t-file__branch-coverage"><%= covered_percent(source_file.branches_coverage_percent) %></td>
           <td class="cell--number"><%= source_file.total_branches.count %></td>
           <td class="cell--number"><%= source_file.covered_branches.count %></td>
           <td class="cell--number"><%= source_file.missed_branches.count %></td>
+<%- end -%>
+<%- if method_coverage? -%>
+          <td class="strong cell--number t-file__method-coverage"><%= covered_percent(source_file.methods_coverage_percent) %></td>
+          <td class="cell--number"><%= source_file.methods.count %></td>
+          <td class="cell--number"><%= source_file.covered_methods.count %></td>
+          <td class="cell--number"><%= source_file.missed_methods.count %></td>
 <%- end -%>
         </tr>
 <%- end -%>

views/layout.erb

@@ -18,7 +18,7 @@
     </script>
   </head>
 
-  <body<%= ' data-branch-coverage=true' if branchable_result? %>>
+  <body<%= ' data-branch-coverage=true' if branch_coverage? %>>
     <button id="dark-mode-toggle"></button>
     <div id="loading">
       <img src="<%= assets_path('loading.gif') %>" alt="loading"/>

views/source_file.erb

@@ -5,23 +5,46 @@
       <%= covered_percent(source_file.covered_percent) %>
       lines covered
     </h4>
-<%- if branchable_result? -%>
+<%- if branch_coverage? -%>
     <h4>
       <%= covered_percent(source_file.branches_coverage_percent) %>
       branches covered
     </h4>
+<%- end -%>
+<%- if method_coverage? -%>
+    <h4>
+      <%= covered_percent(source_file.methods_coverage_percent) %>
+      methods covered
+    </h4>
 <%- end -%>
     <div class="t-line-summary">
       <b><%= source_file.lines_of_code %></b> relevant lines.
       <span class="green"><b><%= source_file.covered_lines.count %></b> lines covered</span> and
       <span class="red"><b><%= source_file.missed_lines.count %></b> lines missed.</span>
     </div>
-<%- if branchable_result? -%>
+<%- if branch_coverage? -%>
     <div class="t-branch-summary">
         <span><b><%= source_file.total_branches.count %></b> total branches, </span>
         <span class="green"><b><%= source_file.covered_branches.count %></b> branches covered</span> and
         <span class="red"><b><%= source_file.missed_branches.count %></b> branches missed.</span>
     </div>
+<%- end -%>
+<%- if method_coverage? -%>
+    <div class="t-method-summary">
+        <span><b><%= source_file.methods.count %></b> total methods, </span>
+        <span class="green"><b><%= source_file.covered_methods.count %></b> methods covered</span> and
+        <span class="red"><b><%= source_file.missed_methods.count %></b> methods missed.</span>
+    </div>
+<%- end -%>
+<%- if method_coverage? && source_file.missed_methods.any? -%>
+    <div class="t-missed-method-summary">
+      <span>Missed methods:</span>
+      <ul>
+<%- source_file.missed_methods.each do |missed_method| -%>
+        <li><tt><%= ERB::Util.html_escape(missed_method.to_s) %></tt></li>
+<%- end -%>
+      </ul>
+    </div>
 <%- end -%>
   </div>
   <pre>
@@ -33,7 +56,7 @@
 <%- elsif line.skipped? -%>
         <span class="hits">skipped</span>
 <%- end -%>
-<%- if branchable_result? -%>
+<%- if branch_coverage? -%>
 <%- source_file.branches_for_line(line.number).each do |branch_type, hit_count| -%>
         <span class="hits" title="<%= branch_type%> branch hit <%= hit_count %> times"><%= branch_type %>: <%= hit_count %></span>
 <%- end -%>