Actionable code coverage.
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
- Missing coverage on every π test run
- Catch coverage issues before making PRs
- Easily add coverage enforcement for legacy apps
- 2-5% runtime overhead on small files, compared to 20% for
SimpleCov
- Branch coverage (disable via
branches: false
) - Use with forking_test_runner for exact per test coverage
# 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 ...
Each covered!
call expects to find a matching file, if it does not:
# 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'
Add the inline comment # uncovered
to ignore uncovered code.
Prevent addition of new uncovered code, without having to cover all existing code by marking how many lines are uncovered:
SingleCov.covered! uncovered: 4
For example packwerk components are hosted in public
and not lib/public
SingleCov::PREFIXES_TO_IGNORE << "public"
When a report shows for example 1:14-16 # else
, that indicates that the implicit else is not covered.
# 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
Run this from irb
to get SingleCov added to all test files.
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
When a single integration test covers multiple source files.
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
Michael Grosser
[email protected]
License: MIT