# Gemfile
gem 'single_cov', group: :test

# spec/spec_helper.rb ... load single_cov before rails, libraries, minitest, or rspec
require 'single_cov'
SingleCov.setup :rspec # or :minitest

# spec/foobar_spec.rb ... add covered! call to test files
require 'spec_helper'
SingleCov.covered!

describe "xyz" do ...

# change all guessed paths
SingleCov.rewrite { |f| f.sub('lib/unit/', 'app/models/') }

# mark directory as being in app and not lib
SingleCov::RAILS_APP_FOLDERS << 'presenters'

# add 1-off
SingleCov.covered! file: 'scripts/weird_thing.rb'

SingleCov.covered! uncovered: 4

SingleCov::PREFIXES_TO_IGNORE << "public"

# needs 2 tests: one for `true` and one for `false`
raise if a == b

# needs 2 tests: one for `when b` and one for `else`
case a
when b
end

# spec/coverage_spec.rb
SingleCov.not_covered! # not testing any code in lib/

describe "Coverage" do
  # recommended
  it "does not allow new tests without coverage check" do
    # option :tests to pass custom Dir.glob results
    SingleCov.assert_used
  end

  # recommended
  it "does not allow new untested files" do
    # option :tests and :files to pass custom Dir.glob results
    # :untested to get it passing with known untested files
    SingleCov.assert_tested
  end
  
  # optional for full coverage enforcement
  it "does not reduce full coverage" do
    # make sure that nobody adds `uncovered: 123` to any test that did not have it before
    # option :tests to pass custom Dir.glob results
    # option :currently_complete for expected list of full covered tests
    # option :location for if you store that list in a separate file
    SingleCov.assert_full_coverage currently_complete: ["test/a_test.rb"]
  end
end

tests = Dir['spec/**/*_spec.rb']
command = "bundle exec rspec %{file}"

tests.each do |f|
  content = File.read(f)
  next if content.include?('SingleCov.')

  # add initial SingleCov call
  content = content.split(/\n/, -1)
  insert = content.index { |l| l !~ /require/ && l !~ /^#/ }
  content[insert...insert] = ["", "SingleCov.covered!"]
  File.write(f, content.join("\n"))

  # run the test to check coverage
  result = `#{command.sub('%{file}', f)} 2>&1`
  if $?.success?
    puts "#{f} is good!"
    next
  end

  if uncovered = result[/\((\d+) current/, 1]
    # configure uncovered
    puts "Uncovered for #{f} is #{uncovered}"
    content[insert+1] = "SingleCov.covered! uncovered: #{uncovered}"
    File.write(f, content.join("\n"))
  else
    # mark bad tests for manual cleanup
    content[insert+1] = "# SingleCov.covered! # TODO: manually fix this"
    File.write(f, content.join("\n"))
    puts "Manually fix: #{f} ... output is:\n#{result}"
  end
end

SingleCov.covered! file: 'app/modes/user.rb'
SingleCov.covered! file: 'app/mailers/user_mailer.rb'
SingleCov.covered! file: 'app/controllers/user_controller.rb'

SingleCov.coverage_report = "coverage/.resultset.json"
SingleCov.coverage_report_lines = true # only report line coverage for coverage systems that do not support branch coverage