Fix Metrics/AbcSize offenses by refactoring

Drop the `Metrics/AbcSize: Max: 25` override from .rubocop.yml and clear
the three offenses that surface against the default cap of 17.

Author: sferik

.rubocop.yml

@@ -62,10 +62,6 @@ Lint/Void:
   Exclude:
     - "spec/fixtures/html_formatter/**/*"
 
-Metrics/AbcSize:
-  Description: Checks that the ABC size of methods is not higher than the configured maximum.
-  Max: 25 # TODO: Lower to 15
-
 Metrics/BlockLength:
   Description: Checks if the length of a block exceeds some maximum value.
   Exclude:

lib/simplecov.rb

@@ -153,15 +153,16 @@ def filtered(files)
     # Applies the configured groups to the given array of SimpleCov::SourceFile items
     #
     def grouped(files)
-      grouped = {}
-      grouped_files = []
-      groups.each do |name, filter|
-        grouped[name] = SimpleCov::FileList.new(files.select { |source_file| filter.matches?(source_file) })
-        grouped_files += grouped[name]
-      end
-      if !groups.empty? && !(other_files = files.reject { |source_file| grouped_files.include?(source_file) }).empty?
-        grouped["Ungrouped"] = SimpleCov::FileList.new(other_files)
+      return {} if groups.empty?
+
+      grouped = groups.transform_values do |filter|
+        SimpleCov::FileList.new(files.select { |source_file| filter.matches?(source_file) })
       end
+
+      in_group  = grouped.values.flat_map(&:to_a)
+      ungrouped = files.reject { |source_file| in_group.include?(source_file) }
+      grouped["Ungrouped"] = SimpleCov::FileList.new(ungrouped) if ungrouped.any?
+
       grouped
     end
 

lib/simplecov/source_file.rb

@@ -284,15 +284,18 @@ def build_lines
     end
 
     def process_skipped_lines(lines)
-      # the array the lines are kept in is 0-based whereas the line numbers in the nocov
-      # chunks are 1-based and are expected to be like this in other parts (and it's also
-      # arguably more understandable)
-      no_cov_chunks.each { |chunk| lines[(chunk.begin - 1)..(chunk.end - 1)].each(&:skipped!) }
-      directive_chunks.fetch(:line).each { |chunk| lines[(chunk.begin - 1)..(chunk.end - 1)].each(&:skipped!) }
-
+      mark_chunks_skipped(lines, no_cov_chunks)
+      mark_chunks_skipped(lines, directive_chunks.fetch(:line))
       lines
     end
 
+    # The array the lines are kept in is 0-based whereas the line numbers
+    # in the chunks are 1-based (more understandable elsewhere), so each
+    # range needs to be shifted down by one to slice into `lines`.
+    def mark_chunks_skipped(lines, chunks)
+      chunks.each { |chunk| lines[(chunk.begin - 1)..(chunk.end - 1)].each(&:skipped!) }
+    end
+
     def lines_strength
       lines.sum { |line| line.coverage.to_i }
     end

spec/coverage_statistics_spec.rb

@@ -71,13 +71,15 @@ def empty_statistics
   end
 
   def expect_all_empty(statistics)
-    expect(statistics.covered).to eq 0
-    expect(statistics.missed).to eq 0
-    expect(statistics.omitted).to eq 0
-
-    expect(statistics.total).to eq 0
-    # might be counter-intuitive but think of it as "we covered everything we could"
-    expect(statistics.percent).to eq 100.0
-    expect(statistics.strength).to eq 0.0
+    # 100% / 0.0 strength might be counter-intuitive but think of it as "we
+    # covered everything we could".
+    expect(statistics).to have_attributes(
+      covered:  0,
+      missed:   0,
+      omitted:  0,
+      total:    0,
+      percent:  100.0,
+      strength: 0.0
+    )
   end
 end