Extract build_output_text method to BenchmarkRunner module

Author: rafaelfranca

lib/benchmark_runner.rb

@@ -3,6 +3,7 @@
 require 'csv'
 require 'json'
 require 'rbconfig'
+require_relative 'table_formatter'
 
 # Extracted helper methods from run_benchmarks.rb for testing
 module BenchmarkRunner
@@ -46,6 +47,28 @@ def write_csv(output_path, ruby_descriptions, table)
       out_csv_path
     end
 
+    # Build output text string with metadata, table, and legend
+    def build_output_text(ruby_descriptions, table, format, bench_failures, base_name, other_names)
+      output_str = +""
+
+      ruby_descriptions.each do |key, value|
+        output_str << "#{key}: #{value}\n"
+      end
+
+      output_str << "\n"
+      output_str << TableFormatter.new(table, format, bench_failures).to_s + "\n"
+
+      unless other_names.empty?
+        output_str << "Legend:\n"
+        other_names.each do |name|
+          output_str << "- #{name} 1st itr: ratio of #{base_name}/#{name} time for the first benchmarking iteration.\n"
+          output_str << "- #{base_name}/#{name}: ratio of #{base_name}/#{name} time. Higher is better for #{name}. Above 1 represents a speedup.\n"
+        end
+      end
+
+      output_str
+    end
+
     # Render a graph from JSON benchmark data
     def render_graph(json_path)
       png_path = json_path.sub(/\.json$/, '.png')

run_benchmarks.rb

@@ -11,7 +11,6 @@
 require_relative 'lib/cpu_config'
 require_relative 'lib/benchmark_runner'
 require_relative 'lib/benchmark_suite'
-require_relative 'lib/table_formatter'
 require_relative 'lib/argument_parser'
 require_relative 'lib/results_table_builder'
 
@@ -77,19 +76,7 @@
 BenchmarkRunner.write_csv(output_path, ruby_descriptions, table)
 
 # Save the output in a text file that we can easily refer to
-output_str = ""
-ruby_descriptions.each do |key, value|
-  output_str << "#{key}: #{value}\n"
-end
-output_str += "\n"
-output_str += TableFormatter.new(table, format, bench_failures).to_s + "\n"
-unless other_names.empty?
-  output_str << "Legend:\n"
-  other_names.each do |name|
-    output_str << "- #{name} 1st itr: ratio of #{base_name}/#{name} time for the first benchmarking iteration.\n"
-    output_str << "- #{base_name}/#{name}: ratio of #{base_name}/#{name} time. Higher is better for #{name}. Above 1 represents a speedup.\n"
-  end
-end
+output_str = BenchmarkRunner.build_output_text(ruby_descriptions, table, format, bench_failures, base_name, other_names)
 out_txt_path = output_path + ".txt"
 File.open(out_txt_path, "w") { |f| f.write output_str }
 

test/benchmark_runner_test.rb

@@ -365,6 +365,150 @@
     end
   end
 
+  describe '.build_output_text' do
+    it 'builds output text with metadata, table, and legend' do
+      ruby_descriptions = {
+        'ruby-base' => 'ruby 3.3.0',
+        'ruby-yjit' => 'ruby 3.3.0 +YJIT'
+      }
+      table = [
+        ['bench', 'ruby-base (ms)', 'stddev (%)', 'ruby-yjit (ms)', 'stddev (%)'],
+        ['fib', '100.0', '5.0', '50.0', '3.0']
+      ]
+      format = ['%s', '%.1f', '%.1f', '%.1f', '%.1f']
+      bench_failures = {}
+      base_name = 'ruby-base'
+      other_names = ['ruby-yjit']
+
+      result = BenchmarkRunner.build_output_text(
+        ruby_descriptions, table, format, bench_failures, base_name, other_names
+      )
+
+      assert_includes result, 'ruby-base: ruby 3.3.0'
+      assert_includes result, 'ruby-yjit: ruby 3.3.0 +YJIT'
+      assert_includes result, 'Legend:'
+      assert_includes result, '- ruby-yjit 1st itr: ratio of ruby-base/ruby-yjit time for the first benchmarking iteration.'
+      assert_includes result, '- ruby-base/ruby-yjit: ratio of ruby-base/ruby-yjit time. Higher is better for ruby-yjit. Above 1 represents a speedup.'
+    end
+
+    it 'includes formatted table in output' do
+      ruby_descriptions = { 'ruby' => 'ruby 3.3.0' }
+      table = [
+        ['bench', 'ruby (ms)', 'stddev (%)'],
+        ['fib', '100.0', '5.0']
+      ]
+      format = ['%s', '%.1f', '%.1f']
+      bench_failures = {}
+      base_name = 'ruby'
+      other_names = []
+
+      result = BenchmarkRunner.build_output_text(
+        ruby_descriptions, table, format, bench_failures, base_name, other_names
+      )
+
+      # Should contain table headers
+      assert_includes result, 'bench'
+      assert_includes result, 'ruby (ms)'
+      # Should contain table data
+      assert_includes result, 'fib'
+      assert_includes result, '100.0'
+    end
+
+    it 'omits legend when no other executables' do
+      ruby_descriptions = { 'ruby' => 'ruby 3.3.0' }
+      table = [['bench', 'ruby (ms)'], ['fib', '100.0']]
+      format = ['%s', '%.1f']
+      bench_failures = {}
+      base_name = 'ruby'
+      other_names = []
+
+      result = BenchmarkRunner.build_output_text(
+        ruby_descriptions, table, format, bench_failures, base_name, other_names
+      )
+
+      refute_includes result, 'Legend:'
+    end
+
+    it 'handles multiple other executables in legend' do
+      ruby_descriptions = {
+        'ruby' => 'ruby 3.3.0',
+        'ruby-yjit' => 'ruby 3.3.0 +YJIT',
+        'ruby-rjit' => 'ruby 3.3.0 +RJIT'
+      }
+      table = [['bench', 'ruby (ms)', 'ruby-yjit (ms)', 'ruby-rjit (ms)']]
+      format = ['%s', '%.1f', '%.1f', '%.1f']
+      bench_failures = {}
+      base_name = 'ruby'
+      other_names = ['ruby-yjit', 'ruby-rjit']
+
+      result = BenchmarkRunner.build_output_text(
+        ruby_descriptions, table, format, bench_failures, base_name, other_names
+      )
+
+      assert_includes result, 'ruby-yjit 1st itr'
+      assert_includes result, 'ruby-rjit 1st itr'
+      assert_includes result, 'ruby/ruby-yjit'
+      assert_includes result, 'ruby/ruby-rjit'
+    end
+
+    it 'includes benchmark failures in formatted output' do
+      ruby_descriptions = { 'ruby' => 'ruby 3.3.0' }
+      table = [['bench', 'ruby (ms)'], ['fib', '100.0']]
+      format = ['%s', '%.1f']
+      bench_failures = {
+        'ruby' => { 'failed_bench' => 'error message' }
+      }
+      base_name = 'ruby'
+      other_names = []
+
+      result = BenchmarkRunner.build_output_text(
+        ruby_descriptions, table, format, bench_failures, base_name, other_names
+      )
+
+      # TableFormatter handles displaying failures, just verify it's called
+      assert_kind_of String, result
+      assert result.length > 0
+    end
+
+    it 'handles empty ruby_descriptions' do
+      ruby_descriptions = {}
+      table = [['bench']]
+      format = ['%s']
+      bench_failures = {}
+      base_name = 'ruby'
+      other_names = []
+
+      result = BenchmarkRunner.build_output_text(
+        ruby_descriptions, table, format, bench_failures, base_name, other_names
+      )
+
+      assert_kind_of String, result
+      assert result.start_with?("\n") # Should start with newline after empty descriptions
+    end
+
+    it 'preserves order of ruby_descriptions' do
+      ruby_descriptions = {
+        'ruby-a' => 'version A',
+        'ruby-b' => 'version B',
+        'ruby-c' => 'version C'
+      }
+      table = [['bench']]
+      format = ['%s']
+      bench_failures = {}
+      base_name = 'ruby-a'
+      other_names = []
+
+      result = BenchmarkRunner.build_output_text(
+        ruby_descriptions, table, format, bench_failures, base_name, other_names
+      )
+
+      lines = result.lines
+      assert_includes lines[0], 'ruby-a: version A'
+      assert_includes lines[1], 'ruby-b: version B'
+      assert_includes lines[2], 'ruby-c: version C'
+    end
+  end
+
   describe '.render_graph' do
     it 'delegates to GraphRenderer and returns calculated png_path' do
       Dir.mktmpdir do |dir|