Single Cov CI

rspec spec/foobar_spec.rb
......
114 example, 0 failures
lib/foobar.rb new uncovered lines introduced (2 current vs 0 configured)
Uncovered lines:
lib/foobar.rb:22
lib/foobar.rb:23:6-19

# 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 ...

Missing target file

# 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'

Known uncovered

SingleCov.covered! uncovered: 4

Making a folder not get prefixed with lib/

SingleCov::PREFIXES_TO_IGNORE << "public"

Missing coverage for implicit else in if or case statements

# 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

Verify all code has tests & coverage

# 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

Automatic bootstrap

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

Cover multiple files from a single test

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

Generating a coverage report

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

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