Add main formatter

lib/simplecov/inline.rb

@@ -1,4 +1,5 @@
 require_relative 'inline/version'
+require_relative 'inline/formatter'
 
 module SimpleCov
   module Inline

lib/simplecov/inline/formatter.rb

@@ -0,0 +1,101 @@
+module Simplecov
+  module Inline
+    class Formatter
+      Result = Struct.new(:file, :start_line, :end_line, :type) do
+        def to_s
+          lines = [start_line, end_line].uniq.join('-')
+          "#{file}:#{lines} (#{type})"
+        end
+      end
+
+      Config = Struct.new(:files) do
+        def no_output!(reason:)
+          @no_output = reason
+        end
+
+        attr_reader :no_output
+      end
+
+      @config = Config.new
+
+      def self.config(&block)
+        return @config if block.nil?
+
+        block.call(@config)
+
+        return if @config.files.nil?
+
+        @config.files = @config.files.to_set.freeze
+      end
+
+      def format(result, putter: Kernel)
+        missing_coverage = process_files(filtered_files(result:).reject { |file| fully_covered?(file) })
+        success_message = build_success_message(missing_coverage:)
+
+        if success_message
+          putter.puts success_message
+          return
+        end
+
+        putter.puts
+        putter.puts 'Missing coverage:'.yellow
+        putter.puts missing_coverage.yellow
+        putter.puts
+      end
+
+      private
+
+      def build_success_message(missing_coverage:)
+        return "Coverage output skipped. Reason: #{self.class.config.no_output}.".yellow if self.class.config.no_output
+        return "All branches covered (#{human_filter} files) ✔ ".green if missing_coverage.empty?
+
+        nil
+      end
+
+      def fully_covered?(file)
+        [file.covered_percent, file.branches_coverage_percent].all? { |coverage| coverage == 100 }
+      end
+
+      def human_filter
+        self.class.config.files&.length || 'all'
+      end
+
+      def filtered_files(result:)
+        filter = self.class.config.files
+
+        return result.files if filter.nil?
+
+        result.files.filter { |file| filter.include?(file.filename) }
+      end
+
+      def process_files(files)
+        files.map do |file|
+          [
+            build_line_coverage(file),
+            build_branch_coverage(file),
+          ]
+        end.flatten.compact.join("\n")
+      end
+
+      def build_line_coverage(file)
+        file.missed_lines.each_with_object([]) do |uncovered, object|
+          # uncovered is a SimpleCov::SourceFile::Line
+          cursor = object.last
+
+          if cursor&.end_line == uncovered.line_number - 1
+            cursor.end_line = uncovered.line_number
+          else
+            object.push(Result.new(file.project_filename, uncovered.line_number, uncovered.line_number, 'line'))
+          end
+        end
+      end
+
+      def build_branch_coverage(file)
+        file.missed_branches.map do |uncovered|
+          # uncovered is a SimpleCov::SourceFile::Branch
+          Result.new(file.project_filename, uncovered.report_line, uncovered.report_line, "branch:#{uncovered.type}")
+        end
+      end
+    end
+  end
+end

spec/lib/simplecov/inline/formatter_spec.rb

@@ -0,0 +1,36 @@
+RSpec.describe Simplecov::Inline::Formatter do
+  describe '#format' do
+    subject { described_class.new.format(result, putter:) }
+
+    let(:result) do
+      SimpleCov::Result.new({
+        'file1.rb' => {'lines' => [nil, 1, 1]},
+        'file2.rb' => {'lines' => [1, nil]},
+      })
+    end
+
+    let(:putter) { instance_double(Kernel) }
+
+    before { allow(putter).to receive(:puts) }
+
+    it 'outputs missing lines and branches' do
+      subject
+
+      expect(putter).to have_received('Missing coverage:')
+    end
+  end
+
+  describe '.config' do
+    subject { described_class.config }
+
+    it { is_expected.to have_attributes files: nil }
+    it { is_expected.to respond_to :no_output! }
+
+    it 'can change the files' do
+      expect { described_class.config { |config| config.files = ['test.txt'] } }
+        .to change { described_class.config.files }
+        .from(nil)
+        .to(['test.txt'])
+    end
+  end
+end