Report on changed files outside of coverage reports

Previously, a file from Changeset but not in LcovParser#coverage would not
appear as flagged. This changes the behaviour, so that more untested files
are reported.

.rubocop.yml

@@ -24,6 +24,12 @@ Metrics/BlockLength:
   Exclude:
     - spec/**/*
 
+Metrics/CyclomaticComplexity:
+  Max: 10
+
+Metrics/PerceivedComplexity:
+  Max: 10
+
 Style/HashEachMethods:
   Enabled: true
 

.tool-versions

@@ -1 +1 @@
-ruby 3.3.0
+ruby 3.3.3

lib/undercover.rb

@@ -36,7 +36,7 @@ def initialize(changeset, opts)
       @results = {}
     end
 
-    # rubocop:disable Metrics/MethodLength, Metrics/AbcSize, Metrics/CyclomaticComplexity
+    # rubocop:disable Metrics/MethodLength, Metrics/AbcSize
     def build
       changeset.each_changed_line do |filepath, line_no|
         dist_from_line_no = lambda do |res|
@@ -61,7 +61,7 @@ def build
       end
       self
     end
-    # rubocop:enable Metrics/MethodLength, Metrics/AbcSize, Metrics/CyclomaticComplexity
+    # rubocop:enable Metrics/MethodLength, Metrics/AbcSize
 
     def build_warnings
       warn('Undercover::Report#build_warnings is deprecated! ' \
@@ -92,7 +92,6 @@ def load_and_parse_file(filepath)
       return if loaded_files[key]
 
       coverage = lcov.coverage(filepath)
-      return if coverage.empty?
 
       root_ast = Imagen::Node::Root.new.build_from_file(
         File.join(code_dir, filepath)

lib/undercover/result.rb

@@ -27,8 +27,9 @@ def flagged?
       @flagged
     end
 
-    # rubocop:disable Metrics/CyclomaticComplexity
     def uncovered?(line_no)
+      return true if coverage.empty?
+
       # check branch coverage for line_no
       coverage.each do |ln, _block, _branch, cov|
         return true if ln == line_no && cov && cov.zero?
@@ -38,13 +39,16 @@ def uncovered?(line_no)
       line_cov = coverage.select { |cov| cov.size == 2 }.find { |ln, _cov| ln == line_no }
       line_cov && line_cov[1].zero?
     end
-    # rubocop:enable Metrics/CyclomaticComplexity
 
     # Method `coverage_f` returns the total coverage of this Undercover::Result
     # as a % value, taking into account missing branches. Line coverage will be counted
     # as 0 if any branch is untested.
     # rubocop:disable Metrics/AbcSize, Metrics/MethodLength
     def coverage_f
+      if coverage.empty?
+        return node.children.empty? ? 1.0 : 0.0
+      end
+
       lines = {}
       coverage.each do |ln, block_or_line_cov, _, branch_cov|
         lines[ln] = 1 unless lines.key?(ln)

spec/fixtures/test_empty.lcov

@@ -0,0 +1,5 @@
+SF:./program_xyz.rb
+DA:2,1
+DA:3,1
+DA:4,1
+end_of_record

spec/report_spec.rb

@@ -108,5 +108,17 @@
       expect(warnings[1].file_path).to eq('test_two_patches.rb')
       expect(warnings[1].first_line).to eq(15)
     end
+
+    it 'reports changed files that were not in the lcov report' do
+      options.lcov = 'spec/fixtures/test_empty.lcov'
+      report.build
+      warnings = report.build_warnings.to_a
+      expect(warnings.size).to eq(2)
+
+      expect(warnings[0].file_path).to eq('test_two_patches.rb')
+      expect(warnings[0].first_line).to eq(3)
+      expect(warnings[1].file_path).to eq('test_two_patches.rb')
+      expect(warnings[1].first_line).to eq(15)
+    end
   end
 end